Major interaction on record — check this product against your medications before combining. Check your meds →
Dietary supplement

Citrigen Ingredients & Drug Interactions

by Genestra Brands

Citrigen label
See full label image
Capsule Category: Botanical
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Citrigen against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Major

Citrigen is a dietary supplement by Genestra Brands with 4 active ingredients. Its ingredients are commonly taken for irritable bowel syndrome (ibs), indigestion and gas, nausea.Based on those ingredients, 1,476 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Green Tea, Grapefruit (Citrus paradisi) fruit extract, Echinacea. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Citrigen by Genestra Brands

Ask about any prescription or over-the-counter medication and we check it for interactions with Citrigen by Genestra Brands — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
Prefer a human? Send your question to our licensed pharmacists — free, answered by email within 24 hours.

HelloPharmacist Scorecard of Citrigen by Genestra Brands

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 12, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 4 of its 4 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

Citrigen contains four active ingredients. Peppermint is included for its digestive and anti-spasm properties—it's rated likely effective for irritable bowel syndrome and possibly effective for indigestion and nausea.

Green tea is added for its antioxidant activity and has been studied for hormone-related conditions and cholesterol. Echinacea, an immune-stimulating herb, appears in this formula, though the evidence for its effectiveness is currently insufficient to rate for most uses.

Grapefruit (citrus) fruit extract rounds out the blend; its effectiveness is similarly unproven in the data we hold. The product also contains inactive ingredients—hypromellose, cellulose, magnesium silicate, and magnesium stearate—which are binders and fillers that hold the capsule together.

Does it work?

Strong evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed

This product doesn't appear to be marketed for a specific use, so we graded its ingredients' overall clinical evidence instead.

Strong

Strong clinical evidence supports its ingredients for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredients' overall clinical evidence instead.
  • On file: Irritable bowel syndrome (IBS) — rated "Likely Effective" (Peppermint) (Natural Medicines).
  • On file: Human papillomavirus (HPV) — rated "Likely Effective" (Green Tea) (Natural Medicines).
  • On file: Barium enema-related colonic spasm — rated "Possibly Effective" (Peppermint) (Natural Medicines).
  • On file: Cardiovascular disease (CVD) — rated "Possibly Effective" (Green Tea) (Natural Medicines).
  • On file: Chemotherapy-induced nausea and vomiting (CINV) — rated "Possibly Effective" (Peppermint) (Natural Medicines).

The evidence supporting Citrigen's active ingredients is mixed. Peppermint alone has solid backing: it's rated likely effective for irritable bowel syndrome and possibly effective for indigestion, nausea from chemotherapy, and certain procedures.

For green tea, echinacea, and grapefruit extract, however, the data we hold shows insufficient or no established evidence for their intended uses in a formula like this. Green tea has been studied for hormone-related cancers and cholesterol, but results vary.

Echinacea and grapefruit extract have no proven effectiveness ratings in our records.

The evidence, ingredient by ingredient Peppermint Green Tea Echinacea Grapefruit

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 4 of the 4 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 4 of 4.
  • General safety write-ups exist for 4 of 4.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Peppermint is rated likely safe in pregnancy and lactation, and it's generally well tolerated when taken orally—though it may cause abdominal pain, heartburn, nausea, diarrhea, or dry mouth in some people. Green tea is possibly safe in pregnancy and lactation, but concentrated extracts at high doses carry a rare risk of liver injury; keep intake moderate.

Echinacea is possibly safe in pregnancy, with insufficient safety data for lactation; allergic reactions (especially in people sensitive to ragweed or related plants) and rare cases of liver inflammation have been reported. Grapefruit is generally well tolerated when eaten as whole fruit, but the product here contains a concentrated extract whose safety profile is not well studied.

Large quantities of grapefruit can cause heart rhythm problems, and regular high consumption has been linked in preliminary research to increased breast cancer risk in postmenopausal women.

Side effects, ingredient by ingredient Peppermint Green Tea Echinacea Grapefruit

Meds to double-check

Major interaction found
Known Interaction Concern · database check
Major identified

At least one ingredient has a documented Major-severity interaction. Check your medications for a personalized result.

Why this rating?
  • 4 of the 4 matched ingredients can interact with medications — Peppermint, Grapefruit, Green Tea, Echinacea.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs; diabetes medications; heart-rhythm medications; lithium.
  • For scale: 1,477 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking Citrigen, double-check with your pharmacist or doctor if you take any of the following. Most critical: nadolol or other beta-blockers (green tea can slash nadolol levels by 85%), atorvastatin or other cholesterol drugs (green tea may reduce effectiveness), buspirone, amiodarone, dextromethorphan, scopolamine, cyclosporine, or ephedrine—grapefruit and green tea can dangerously raise their levels.

Also ask about seizure medications like phenytoin, valproate, felbamate, and ethosuximide (green tea's caffeine may weaken them), immunosuppressants (echinacea may interfere), and any drug metabolized by CYP2C19, CYP2C9, or CYP3A4 enzymes (peppermint and echinacea may change levels).

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with strong clinical evidence behind its ingredients' uses. Major medication interactions have been identified, and safety information is well characterized.

This product combines peppermint—which has good evidence for digestive complaints—with three ingredients whose effectiveness is unproven or unrated. More importantly, the four-ingredient blend carries major interactions with common heart medications, blood pressure drugs, seizure treatments, and immunosuppressants.

If you take any prescription medications, check them against this product's interaction list before starting. Talk to your pharmacist or doctor about whether Citrigen is right for you, especially if you're on cardiac, psychiatric, or seizure medications.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 4 of 4 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated May 28, 2019.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Citrigen, straight from the product label.

Brand Genestra Brands
Barcode (UPC) 883196100316
Net contents 90 Vegetarian Capsule(s)
Market status On market
Date entered into DSLD May 28, 2019
DSLD ID 203135
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years)
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Citrigen by Genestra Brands, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
2 Capsule(s)
Maximum serving Sizes:
2 Capsule(s)
Servings per container
45
UPC/BARCODE
883196100316
IngredientAmount% DV
Peppermint20 mg--
Green Tea40 mg--
Echinacea500 mg--
Grapefruit (Citrus paradisi) fruit extract240 mg--

Other ingredients: Hypromellose, Cellulose, Magnesium Silicate, Magnesium Stearate

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Suggested/Recommended/Usage/Directions

Recommended dose: Take 2 capsules daily with a meal or as recommended by your health professional.

Precautions

Warning: If you are pregnant or lactating, do not use. If you have any health condition or are taking medication, consult your health professional before use.

Keep out of the reach of children.

Use only if safety seal is intact.

Storage

Store in a cool, dry place.

FDA Disclaimer Statement

This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

General Statements

Contents may not fill package in order to accommodate required labeling. Please rely on stated quantity. Scan to learn about our quality excellence

Traditional support for healthy immune function

General

V5 528-90U

FDA Statement of Identity

Dietary Supplement

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Citrigen by Genestra Brands label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Citrigen label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Citrigen by Genestra Brands

These are the 4 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 Capsule(s) Dosage formCapsule Servings per container45 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Peppermint

Interacts with
796 drugs
20 mg per serving

Peppermint is a popular herb with the best evidence supporting enteric-coated peppermint oil for easing IBS symptoms. It is generally well tolerated f...

Peppermint monograph & interactions

Green Tea

Interacts with
1,293 drugs
40 mg per serving

Green tea is a popular beverage rich in antioxidants called catechins, and drinking it in normal amounts is considered safe for most people. Concentra...

Green Tea monograph & interactions

Echinacea

Interacts with
816 drugs
500 mg per serving

Echinacea is a popular herb taken to help prevent or shorten the common cold, but study results are mixed and the overall benefit appears small at bes...

Echinacea monograph & interactions

Grapefruit (Citrus paradisi) fruit extract

Interacts with
990 drugs
240 mg per serving Form: Bioflavonoids

Grapefruit is a nutritious citrus fruit rich in vitamin C and other nutrients, and it is generally safe to eat. However, grapefruit is famous for seri...

Grapefruit (Citrus paradisi) fruit extract monograph & interactions

Other (inactive) ingredients: Hypromellose, Cellulose, Magnesium Silicate, Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

Citrigen by Genestra Brands Drug Interactions

Want to check YOUR meds against Citrigen?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
1,476Drugs
785 Major 618 Moderate 73 Minor

Ingredients driving the most interactions

Green Tea 1,293
Grapefruit (Citrus paradisi) fruit extract 990
Echinacea 816
Peppermint 796

Individual Drug Interactions

The ingredients in Citrigen interact with 1,476 drugs. Click any drug to see the details.

4 of the 4 ingredients in Citrigen interact with drugs. Each result below shows which ingredient is responsible. Green Tea Grapefruit (Citrus paradisi) fruit extract Echinacea Peppermint

Each ingredient & the kinds of drugs it affects

For each ingredient in Citrigen with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Green Tea58 drug types · 1,293 drugs

Atorvastatin (Lipitor)

Green tea extract seems to reduce the levels and clinical effects of atorvastatin.
In healthy humans, taking green tea extract 300 mg or 600 mg along with atorvastatin reduces plasma levels of atorvastatin by approximately 24%. The elimination of atorvastatin is not affected. Atorvastatin is a substrate of organic anion-transporting polypeptides (OATPs). Research shows that two of the major catechins found in green tea, epicatechin gallate (ECG) and epigallocatechin gallate (EGCG), inhibit OATPs. Some OATPs are expressed in the small intestine and are responsible for the uptake of drugs and other compounds, which may have resulted in reduced plasma levels of atorvastatin. It is not clear if drinking green tea alters the absorption of atorvastatin.

Likelihood Likely Evidence B
Ephedrine

Theoretically, concomitant use might increase the risk for stimulant adverse effects.
Green tea contains caffeine. There is evidence that using ephedrine with caffeine might increase the risk of serious life-threatening or debilitating adverse effects such as hypertension, myocardial infarction, stroke, seizures, and death.

Likelihood Probable Evidence D
Nadolol (Corgard)

Green tea seems to reduce the levels and clinical effects of nadolol.
Preliminary clinical research shows that green tea consumption reduces plasma concentrations of nadolol. Compared to a control group, both peak levels and total drug exposure (AUC) of nadolol were reduced by approximately 85% in subjects who drank green tea daily for two weeks. Drinking green tea with nadolol also significantly reduced nadolol's systolic blood pressure lowering effect. Other clinical research shows that a single dose of green tea can affect plasma nadolol levels for at least one hour. Green tea catechins have been shown to inhibit organic anion transporting polypeptides (OATP), one of which, OATP1A2, is involved in the uptake of nadolol in the intestine The interaction is thought to be due primarily to the epigallocatechin gallate (EGCG) content of green tea.

Likelihood Likely Evidence B
5-Fluorouracil

Theoretically, high doses of green tea might increase the effects and side effects of 5-fluorouracil.
Animal research shows that taking green tea in amounts equivalent to about 6 cups daily in humans for 4 weeks prior to receiving a single injection of 5-fluorouracil increases the maximum plasma levels of 5-fluorouracil by about 2.5-fold and the area under the curve by 425%.

Likelihood Possible Evidence D
Adenosine (Adenocard)

Theoretically, green tea might decrease the vasodilatory effects of adenosine and interfere with its use prior to stress testing.
Green tea contains caffeine. Caffeine is a competitive inhibitor of adenosine at the cellular level. However, caffeine doesn't seem to affect supplemental adenosine because high interstitial levels of adenosine overcome the antagonistic effects of caffeine. It is recommended that methylxanthines and methylxanthine-containing products be stopped 24 hours prior to pharmacological stress tests. However, methylxanthines appear more likely to interfere with dipyridamole (Persantine) than adenosine-induced stress testing.

Likelihood Possible Evidence B
Anticoagulant/Antiplatelet Drugs

Theoretically, green tea may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Conflicting reports exist regarding the effect of green tea on bleeding risk when used with anticoagulant or antiplatelet drugs; however, most evidence suggests that drinking green tea in moderate amounts is unlikely to cause a significant interaction. Green tea contains small amounts of vitamin K, approximately 7 mcg per cup. Some case reports have associated the antagonism of warfarin with the vitamin K content of green tea. However, these reports are rare, and very large doses of green tea (about 8-16 cups daily) appear to be needed to cause these effects. Furthermore, the catechins and caffeine in green tea are reported to have antiplatelet activity.

Likelihood Unlikely Evidence D
Beta-Adrenergic Agonists

Green tea contains caffeine. Theoretically, concomitant use of large amounts of caffeine might increase cardiac inotropic effects of beta-agonists.

Likelihood Probable Evidence D
Bortezomib (Velcade)

Theoretically, green tea might interfere with the effects of bortezomib.
In vitro research shows that green tea polyphenols, such as epigallocatechin gallate (EGCG), interact with bortezomib and block its proteasome inhibitory action. This prevents the induction of cell death in multiple myeloma or glioblastoma cancer cell lines. Advise patients taking bortezomib, not to take green tea.

Likelihood Possible Evidence D
Carbamazepine (Tegretol)

Theoretically, green tea might reduce the effects of carbamazepine and increase the risk for convulsions.
Green tea contains caffeine. Animal research suggests that taking caffeine can lower the anticonvulsant effects of carbamazepine and can induce seizures when taken in doses above 400 mg/kg. Human research has shown that taking caffeine 300 mg in three divided doses along with carbamazepine 200 mg reduces the bioavailability of carbamazepine by 32% and prolongs the plasma half-life of carbamazepine 2-fold in healthy individuals.

Likelihood Possible Evidence D
Celiprolol (Celicard)

Theoretically, green tea might reduce the levels and clinical effects of celiprolol.
In a small human study, taking green tea daily for 4 days appears to decrease blood and urine levels of celiprolol by at least 98%. This interaction is possibly due to the inhibition of organic anion transporting polypeptide (OATP). Green tea catechins have been shown to inhibit organic anion transporting polypeptides (OATP), one of which, OATP1A2, is found in the intestine The interaction is thought to be due primarily to the epigallocatechin gallate (EGCG) content of green tea.

Likelihood Possible Evidence D
Cimetidine (Tagamet)

Theoretically, concomitant use might increase the effects and adverse effects of caffeine in green tea.
Green tea contains caffeine. Cimetidine can reduce caffeine clearance by 31% to 42%.

Likelihood Likely Evidence B
Clozapine (Clozaril)

Theoretically, green tea might increase the levels and adverse effects of clozapine and acutely exacerbate psychotic symptoms.
Animal research suggests that, although green tea extract does not affect the elimination of clozapine, it delays the time to reach peak concentration and reduces the peak plasma levels. Also, concomitant administration of green tea and clozapine might theoretically cause acute exacerbation of psychotic symptoms due to the caffeine in green tea. Caffeine can increase the effects and toxicity of clozapine. Caffeine doses of 400-1000 mg daily inhibit clozapine metabolism. Clozapine is metabolized by cytochrome P450 1A2 (CYP1A2). Researchers speculate that caffeine might inhibit CYP1A2. However, there is no reliable evidence that caffeine affects CYP1A2. There is also speculation that genetic factors might make some patients be more sensitive to the interaction between clozapine and caffeine.

Likelihood Possible Evidence B
Contraceptive Drugs

Theoretically, concomitant use might increase the effects and adverse effects of caffeine found in green tea.
Green tea contains caffeine. Oral contraceptives can decrease caffeine clearance by 40% to 65%.

Likelihood Probable Evidence B
Cytochrome P450 1A2 (Cyp1A2) Inhibitors

Theoretically, concomitant use might increase the levels and adverse effects of caffeine.
Green tea contains caffeine. Caffeine is metabolized by cytochrome P450 1A2 (CYP1A2),. Theoretically, drugs that inhibit CYP1A2 may decrease the clearance rate of caffeine from green tea and increase caffeine levels.

Likelihood Possible Evidence D
Dipyridamole (Persantine)

Theoretically, green tea might decrease the vasodilatory effects of dipyridamole and interfere with its use prior to stress testing.
Green tea contains caffeine. Caffeine might inhibit dipyridamole-induced vasodilation. It is recommended that methylxanthines and methylxanthine-containing products be stopped 24 hours prior to pharmacological stress tests. Methylxanthines appear more likely to interfere with dipyridamole (Persantine) than adenosine-induced stress testing.

Likelihood Probable Evidence B
Disulfiram (Antabuse)

Theoretically, disulfiram might increase the risk of adverse effects from caffeine.
In human research, disulfiram decreases the clearance and increases the half-life of caffeine.

Likelihood Probable Evidence B
Diuretic Drugs

Theoretically, using green tea with diuretic drugs might increase the risk of hypokalemia.
Green tea contains caffeine. In excessive amounts, caffeine can reduce potassium levels due to stimulation of the sodium-potassium pump. Diuretics can also cause lower potassium levels.

Likelihood Possible Evidence D
Estrogens

Theoretically, estrogens might increase the levels and adverse effects of caffeine.
Green tea contains caffeine. Estrogen inhibits caffeine metabolism.

Likelihood Probable Evidence B
Ethosuximide (Zarontin)

Theoretically, green tea might reduce the effects of ethosuximide and increase the risk for convulsions.
Green tea contains caffeine. Animal research suggests that caffeine 92.4 mg/kg can decrease the anticonvulsant activity of ethosuximide. However, this effect has not been reported in humans.

Likelihood Possible Evidence D
Felbamate (Felbatol)

Theoretically, green tea might reduce the effects of felbamate and increase the risk for convulsions.
Green tea contains caffeine. Animal research suggests that a high dose of caffeine 161.7 mg/kg can decreases the anticonvulsant activity of felbamate. However, this effect has not been reported in humans.

Likelihood Possible Evidence D
Fexofenadine (Allegra)

Green tea can decrease blood levels of fexofenadine.
Clinical research shows that green tea can significantly decrease blood levels and excretion of fexofenadine. Taking green tea extract with a dose of fexofenadine decreased bioavailability of fexofenadine by about 30%. In vitro, green tea inhibits the cellular accumulation of fexofenadine by inhibiting the organic anion transporting polypeptide (OATP) drug transporter. Research shows that two of the major catechins found in green tea, epicatechin gallate (ECG) and epigallocatechin gallate (EGCG), inhibit OATPs, specifically OATP1A2, OATP1B1, and OATP2B1. In addition, green tea has been shown to reduce the absorption of some drugs that are OATP substrates.

Likelihood Probable Evidence B
Flutamide (Eulexin)

Theoretically, green tea might increase the levels and adverse effects of flutamide.
Green tea contains caffeine. In vitro evidence suggests that caffeine can inhibit the metabolism of flutamide. Theoretically, concomitant use of caffeine and flutamide might increase serum concentrations of flutamide and increase the risk adverse effects.

Likelihood Possible Evidence D
Fluvoxamine (Luvox)

Theoretically, fluvoxamine might increase the levels and adverse effects of caffeine.
Green tea contains caffeine. Fluvoxamine reduces caffeine metabolism.

Likelihood Probable Evidence D
Hepatotoxic Drugs

Theoretically, concomitant use might have additive adverse hepatotoxic effects.
Green tea extract supplements have been linked to several cases of hepatotoxicity and might have additive hepatotoxic effects with other drugs..

Likelihood Unlikely Evidence D
Imatinib (Gleevec)

Theoretically, green tea might reduce the levels and clinical effects of imatinib.
In animal research, a single dose of green tea extract reduces the area under the curve (AUC) of imatinib by up to approximately 64% and its main metabolite N-desmethyl imatinib by up to approximately 81%. This interaction has not been shown in humans. The mechanism of action is unclear but may involve multiple pathways.

Likelihood Possible Evidence D
Green Tea full monograph & all 58 interactions

Grapefruit (Citrus paradisi) fruit extract62 drug types · 990 drugs

Amiodarone (Cordarone)

Grapefruit juice can increase blood levels of amiodarone, potentially increasing the effects and adverse effects of amiodarone.
Clinical research shows that grapefruit juice inhibits metabolism and increases absorption of amiodarone. Grapefruit juice increases amiodarone plasma levels by 50% and peak concentration by 84%.

Likelihood Probable Evidence B
Artemether (Artenam, Paluther)

Grapefruit juice can increase blood levels of oral artemether, potentially increasing the effects and adverse effects of artemether.
Clinical research shows that grapefruit juice increases the levels of oral artemether by 90% to 250% in healthy males.

Likelihood Likely Evidence B
Benzodiazepines

Grapefruit juice might increase blood levels of some oral benzodiazepines, potentially increasing the effects and adverse effects of these drugs.
Clinical research shows that grapefruit juice can increase plasma triazolam concentrations. Repeated consumption of grapefruit juice greatly increases triazolam concentrations and prolongs the half-life, probably due to inhibition of cytochrome P450 3A4 (CYP3A4). Some studies show that grapefruit juice, particularly when taken in large quantities, reduces the clearance and increases the maximum blood levels, area under the plasma concentration curve (AUC), and duration of effect of midazolam. However, there is no effect on intravenous midazolam. Grapefruit juice has also been shown to increase the maximum blood levels and duration of effect of diazepam, but the clinical significance of this is not known. This interaction does not appear to occur with alprazolam.

Likelihood Likely Evidence B
Buspirone (Buspar)

Grapefruit juice can increase blood levels of buspirone, potentially increasing the effects and adverse effects of buspirone.
Clinical research shows that grapefruit juice increases absorption and plasma concentrations of buspirone.

Likelihood Likely Evidence B
Calcium Channel Blockers

Grapefruit juice can increase blood levels of oral calcium channel blockers, potentially increasing the effects and adverse effects of these drugs.
Clinical research shows that grapefruit juice increases absorption and plasma concentrations of amlodipine, nifedipine, nisoldipine, verapamil, felodipine, nimodipine, nicardipine, diltiazem, pranidipine, nitrendipine, and manidipine, This interaction is likely the result of the inhibition of intestinal metabolism of these drugs by CYP3A4, although some research suggests grapefruit may alter plasma drug levels by reducing the rate of gastric emptying. Consuming grapefruit juice 1 liter daily increases steady state concentrations of verapamil by as much as 50%. However, some references dispute the clinical relevance of the interactions with amlodipine, diltiazem, and verapamil. Other research in healthy individuals suggests plasma levels of felodipine and nifedipine are not affected when given intravenously. There is considerable interindividual variability in the effect of grapefruit juice on drug metabolism, which might account for inconsistent study results. In healthy older adults, the hemodynamic response to felodipine plus grapefruit juice might be influenced by altered autonomic regulation. In older healthy adults, a single dose of grapefruit juice and felodipine enhanced the blood pressure-lowering effects of felodipine. However, after a week of grapefruit juice and felodipine (steady state), the hypotensive activity was reduced, possibly due to compensatory tachycardia. Research indicates it is necessary to withhold grapefruit juice for as long as 3 days to avoid interactions with felodipine and nisoldipine.

Likelihood Likely Evidence B
Carbamazepine (Tegretol)

Grapefruit juice can increase blood levels of carbamazepine, potentially increasing the effects and adverse effects of carbamazepine.
Clinical research shows that grapefruit juice increases absorption and plasma concentrations of carbamazepine.

Likelihood Likely Evidence B
Carvedilol (Coreg)

Grapefruit juice can increase blood levels of carvedilol, potentially increasing the effects and adverse effects of carvedilol.
Clinical research shows that grapefruit juice increases the bioavailability of a single dose of carvedilol by 16%.

Likelihood Likely Evidence B
Celiprolol (Celicard)

Grapefruit juice can decrease blood levels of celiprolol, potentially decreasing the clinical effects of celiprolol.
In human research, taking grapefruit juice within two hours of celiprolol appears to decrease absorption and blood levels of celiprolol by approximately 85%. This interaction is due to grapefruit-induced inhibition of organic anion transporting polypeptide (OATP). Grapefruit juice is thought to affect OATP for only a short time. Therefore, separating drug administration and consumption of grapefruit by at least 4 hours is likely to prevent this interaction.

Likelihood Probable Evidence B
Cisapride (Propulsid)

Grapefruit juice can increase blood levels of cisapride, potentially increasing the effects and adverse effects of cisapride.
Clinical research shows that grapefruit juice increases the absorption and plasma concentrations of cisapride. According to the cisapride prescribing information, grapefruit juice is contraindicated in patients taking cisapride.

Likelihood Likely Evidence B
Clomipramine (Anafranil)

Theoretically, grapefruit juice might increase blood levels of clomipramine, potentially increasing the effects and adverse effects of clomipramine.
Case reports have shown that clomipramine trough levels increase significantly after the addition of grapefruit juice to the therapeutic regimen.

Likelihood Probable Evidence D
Clopidogrel (Plavix)

Grapefruit juice can decrease blood levels of the active metabolite of clopidogrel, thereby decreasing the antiplatelet effect of clopidogrel.
Clopidogrel is an antiplatelet prodrug that is metabolized primarily by cytochrome P450 2C19 (CYP2C19) to form the active metabolite. A small clinical study shows that taking grapefruit juice with clopidogrel decreases plasma levels of the active metabolite by more than 80% and impairs the antiplatelet effect of clopidogrel. This effect is possibly due to grapefruit-induced inhibition of CYP2C19.

Likelihood Probable Evidence B
Cyclosporine (Neoral, Sandimmune)

Grapefruit juice can increase blood levels of oral cyclosporine, potentially increasing the effects and adverse effects of cyclosporine.
Clinical research shows that grapefruit juice increases the absorption and plasma concentrations of cyclosporine. The mechanism of action is unclear. However, there is no effect on intravenous cyclosporine.

Likelihood Likely Evidence B
Cytochrome P450 3A4 (Cyp3A4) Substrates

Grapefruit juice can increase levels of drugs metabolized by CYP3A4.
Clinical research shows that grapefruit juice can inhibit CYP3A4 metabolism of drugs, causing increased drug levels and potentially increasing the risk of adverse effects. When taken orally, effects of grapefruit juice on CYP3A4 levels appear to last at least 48 hours. Grapefruit's ability to inhibit CYP3A4 has even been harnessed to intentionally increase levels of venetoclax, which is metabolized by CYP3A4, in an elderly patient with acute myeloid leukemia who could not afford full dose venetoclax. The lower dose of venetoclax in combination with grapefruit juice resulted in serum levels of venetoclax in the therapeutic reference range of full dose venetoclax and positive treatment outcomes for the patient.
Professional consensus recommends the consideration of patient age, existing medical conditions, additional medications, and the potential for additive adverse effects when evaluating the risks of concomitant use of grapefruit juice with any medication metabolized by CYP3A4. While all patients are at risk for interactions with grapefruit juice consumption, patients older than 70 years of age and those taking multiple medications are at the greatest risk for a serious or fatal interaction with grapefruit juice.

Likelihood Likely Evidence B
Dextromethorphan (Robitussin Dm, Others)

Grapefruit juice can increase blood levels of dextromethorphan, potentially increasing the effects and adverse effects of dextromethorphan.
Clinical research shows that grapefruit juice can inhibit cytochrome P450 3A4 (CYP3A4) metabolism, causing increased dextromethorphan levels.

Likelihood Probable Evidence B
Estrogens

Grapefruit juice can increase blood levels of estrogens, potentially increasing the effects and adverse effects of estrogens.
Clinical research shows that grapefruit increases the levels of endogenous and exogenous estrogens by inhibiting cytochrome P450 3A4 (CYP3A4) enzymes. Grapefruit juice increases exogenously administered 17-beta-estradiol by about 20% in females without ovaries and ethinyl-estradiol in healthy females.

Likelihood Probable Evidence B
Etoposide (Vepesid)

Grapefruit juice can decrease blood levels of etoposide, potentially decreasing the clinical effects of etoposide.
Clinical research shows that grapefruit juice decreases the absorption and plasma concentrations of etoposide. There is some evidence that grapefruit juice co-administered with oral etoposide can reduce levels of etoposide by about 26%. Grapefruit juice seems to inhibit organic anion transporting polypeptide (OATP), which is a drug transporter in the gut, liver, and kidney. Grapefruit juice is thought to affect OATP for only a short time. Therefore, separating drug administration and consumption of grapefruit by at least 4 hours is likely to prevent this interaction.

Likelihood Probable Evidence B
Halofantrine

Grapefruit juice can increase blood levels of halofantrine, potentially increasing the effects and adverse effects of halofantrine.
Clinical research shows that grapefruit juice inhibits cytochrome P450 3A4 (CYP3A4) metabolism, which increases halofantrine levels and peak concentration, as well as a marker of ventricular tachyarrhythmia potential.

Likelihood Probable Evidence B
Hmg-Coa Reductase Inhibitors ("Statins")

Grapefruit juice can increase blood levels of statins that are metabolized by cytochrome P450 3A4 (CYP3A4), potentially increasing the effects and adverse effects of these statins. Additionally, grapefruit juice might interfere with the bioavailability of statins that are substrates of organic anion transporting polypeptides (OATP).
Clinical research shows that grapefruit juice inhibits metabolism and increases absorption and plasma concentrations of statins that are metabolized by CYP3A4. These include lovastatin, simvastatin, and atorvastatin. Keep in mind that there is considerable variability in the effect of grapefruit juice on drug metabolism, so individual patient response is difficult to predict.
Some statins, including pravastatin, fluvastatin, pitavastatin, and rosuvastatin, are not metabolized by CYP3A4. However, grapefruit juice might still affect the bioavailability of these statins. These statins are substrates of OATP. Grapefruit juice can inhibit OATP. Therefore, grapefruit juice may reduce the bioavailability or increase drug levels of these statins depending on the type of OATP. However, grapefruit juice affects OATP for only a short time. Therefore, separating drug administration by at least 4 hours is likely to avoid this interaction.

Likelihood Likely Evidence B
Methadone (Dolophine)

Grapefruit juice can increase blood levels of methadone, potentially increasing the effects and adverse effects of methadone.
Clinical research shows that grapefruit juice inhibits the metabolism of methadone, increasing methadone levels and peak concentrations. In one case, a 51-year-old male taking methadone 90 mg daily and no other medications was found unresponsive. The patient reported drinking grapefruit juice 500 mL daily for 3 days prior to the event. Methadone is a substrate of cytochrome P450 3A4 (CYP3A4), and grapefruit juice-induced inhibition of CYP3A4 is the likely cause of this interaction.

Likelihood Probable Evidence B
Methylprednisolone

Grapefruit juice can increase blood levels of methylprednisolone, potentially increasing the effects and adverse effects of methylprednisolone.
Clinical research shows that grapefruit juice can increase the plasma concentration of orally administered methylprednisolone. Grapefruit juice 200 mL three times daily given with methylprednisolone 16 mg increased methylprednisolone half-life by 35%, peak plasma concentration by 27%, and total area under the curve by 75%.

Likelihood Likely Evidence B
Organic Anion-Transporting Polypeptide Substrates (Oatp)

Grapefruit juice can decrease levels of drugs that are substrates of OATP.
In vitro and clinical research show that consuming grapefruit juice inhibits OATP, which reduces the bioavailability of oral drugs that are substrates of OATP. Various clinical studies have shown reduced absorption of OATP substrates when taken with grapefruit, including fexofenadine, acebutolol, aliskiren, celiprolol, levothyroxine, nadolol, and pitavastatin. Grapefruit juice is thought to affect OATP for only a short time. Therefore, separating drug administration and consumption of grapefruit by at least 4 hours is likely to prevent this interaction.

Likelihood Likely Evidence B
Praziquantel (Biltricide)

Grapefruit juice can increase blood levels of praziquantel, potentially increasing the effects and adverse effects of praziquantel.
Clinical research shows that grapefruit juice can inhibit cytochrome P450 3A4 (CYP3A4) metabolism of praziquantel. Plasma concentrations of praziquantel can increase by as much as 160% when administered with 250 mL of commercially available grapefruit juice.

Likelihood Probable Evidence B
Qt Interval-Prolonging Drugs

Grapefruit or grapefruit juice, especially if consumed in large amounts, can cause additive QT interval prolongation when taken with QT interval-prolonging drugs, potentially increasing the risk of ventricular arrhythmias.
Clinical research in healthy volunteers shows that drinking 6 liters of grapefruit juice over 6 hours prolonged the QTc by a peak amount of 14 milliseconds (ms). This prolongation was similar to the QT prolongation caused by the drug moxifloxacin. In individuals with long QT syndrome, a smaller dose of grapefruit juice, 1.5 liters, resulted in a greater peak QTc prolongation of about 30 ms. The effect of smaller quantities of grapefruit juice on the QT interval is unclear.

Likelihood Probable Evidence B
Quetiapine (Seroquel)

Grapefruit juice may increase blood levels of quetiapine, increasing the effects and adverse effects of quetiapine.
Quetiapine is metabolized by cytochrome P450 3A4 (CYP3A4). Grapefruit can inhibit CYP3A4. In one case report, a healthy 28-year-old female with bipolar disorder stabilized on quetiapine 800 mg daily presented with quetiapine toxicity considered to be related to consuming a gallon of grapefruit juice over the past 24 hours.

Likelihood Probable Evidence B
Quinidine

Grapefruit juice can alter blood levels of quinidine, potentially increasing or decreasing the clinical effects of quinidine.
Clinical research shows that grapefruit juice decreases quinidine absorption, clearance, and metabolism, and prolongs the half-life by about 20%.

Likelihood Probable Evidence B
Grapefruit (Citrus paradisi) fruit extract full monograph & all 62 interactions

Echinacea12 drug types · 816 drugs

Caffeine

Echinacea can increase plasma levels of caffeine by inhibiting its metabolism.
Echinacea seems to increase plasma concentrations of caffeine by around 30%. This is likely due to inhibition of cytochrome P450 1A2 (CYP1A2) by echinacea.

Likelihood Probable Evidence B
Cytochrome P450 1A2 (Cyp1A2) Substrates

Echinacea might inhibit the metabolism of CYP1A2 and increase plasma levels of some drugs.
Echinacea appears to inhibit CYP1A2 enzymes in humans. Additionally, echinacea seems to increase plasma concentrations of caffeine, a CYP1A2 substrate, by around 30%. Theoretically, echinacea might increase levels of other drugs metabolized by CYP1A2.

Likelihood Possible Evidence B
Cytochrome P450 3A4 (Cyp3A4) Substrates

Echinacea may induce hepatic CYP3A4 and inhibit intestinal CYP3A4. This may increase or decrease levels of drugs metabolized by CYP3A4.
Several clinical trials have shown that taking echinacea for up to one month does not significantly affect the metabolism of various CYP3A4 substrates, including midazolam, docetaxel, etravirine, lopinavir-ritonavir, and darunavir-ritonavir. However, other clinical research shows that echinacea may increase the clearance of midazolam, suggesting that echinacea might induce CYP3A4. The discrepancy is thought to be due to differing effects of echinacea on intestinal versus hepatic CYP3A4 enzymes. Echinacea appears to induce hepatic CYP3A4 but inhibit intestinal CYP3A4. In some cases, these effects might cancel each other out, but in others, drug levels may be increased or decreased depending on the level of effect at hepatic and intestinal sites. The effect of echinacea on CYP3A4 activity may differ depending on the CYP3A4 substrate.

Likelihood Possible Evidence B
Etoposide (Vepesid)

Echinacea may increase levels of etoposide.
In one report, concomitant use of etoposide and echinacea was associated with more severe thrombocytopenia than the use of etoposide alone, suggesting inhibition of etoposide metabolism. Etoposide is a cytochrome P450 3A4 (CYP3A4) substrate. Echinacea has variable effects on CYP3A4, but some studies have reported inhibition of the enzyme.

Likelihood Possible Evidence D
Immunosuppressants

Echinacea has immunostimulant activity which may interfere with immunosuppressant therapy.
Theoretically, echinacea may interfere with immunosuppressant therapy because of its immunostimulant activity.

Likelihood Possible Evidence B
Darunavir (Prezista)

Theoretically, echinacea may interfere with the metabolism of darunavir; however, a small clinical study found no effect.
Darunavir is metabolized by cytochrome P450 3A4 (CYP3A4) and is administered with the CYP3A4 inhibitor ritonavir to increase its plasma concentrations. Echinacea has variable effects on CYP3A4, but administration of an E. purpurea root extract (Arkocapsulas Echinacea, Arkopharma) 500 mg four times daily for 14 days did not affect darunavir/ritonavir pharmacokinetics in 15 HIV-infected patients.

Likelihood Unlikely Evidence B
Dayquil Severe

Echinacea is reported to have varying effects on a number of Cytochrome P450 metabolizing enzymes in the liver, including CYP1A2 and CYP3A4, which play a role in acetaminophen and dextromethorphan metabolism (both contained in DayQuil Severe), respectively. Studies have reported both enzyme inhibition and induction, making it difficult to predict clinically significant drug interactions with reliability. Specific drug interaction studies reporting definitive results are rare, and potential drug interactions involving echinacea should likely be taken on a case-by-case basis. Based on what we know about how acetaminophen and dextromethorphan are metabolized, the risk of a clinically significant interaction between echinacea and DayQuil Severe is low.

Likelihood Unlikely Evidence A
Docetaxel (Taxotere)

Theoretically, echinacea may interfere with the metabolism of docetaxel; however, a small clinical study found no effect.
Docetaxel is metabolized by cytochrome P450 3A4 (CYP3A4). Echinacea has variable effects on CYP3A4, but taking E. purpurea whole plant extract (Echinaforce, A. Vogel Biopharma AG) 20 drops three times daily for 2 weeks did not alter the pharmacokinetics of docetaxel in one clinical study.

Likelihood Unlikely Evidence B
Etravirine (Intelence)

Theoretically, echinacea may interfere with the metabolism of etravirine; however, a small clinical study found no effect.
Etravirine is metabolized by cytochrome P450 3A4 (CYP3A4). Echinacea has variable effects on CYP3A4, but taking E. purpurea root extract (Arkocapsulas Echinacea, Arkopharma) 500 mg three times daily for 14 days did not alter the pharmacokinetics of etravirine in HIV-infected patients.

Likelihood Unlikely Evidence B
Lopinavir/Ritonavir (Kaletra)

Theoretically, echinacea may interfere with the metabolism of lopinavir; however, a small clinical study found no effect.
Lopinavir is metabolized by cytochrome P450 3A4 (CYP3A4) and is administered with the CYP3A4 inhibitor ritonavir to increase its plasma concentrations. Echinacea has variable effects on CYP3A4, but taking E. purpurea (Echinamide, Natural Factors Nutritional Products, Inc.) 500 mg three times daily for 14 days did not alter the pharmacokinetics of lopinavir/ritonavir in healthy volunteers.

Likelihood Unlikely Evidence B
Midazolam (Versed)

Theoretically, echinacea may increase the metabolism of intravenous midazolam.
Echinacea induces hepatic CYP3A4 and might decrease plasma levels of midazolam by about 20%, reducing the effectiveness of intravenous midazolam. Echinacea also appears to inhibit intestinal CYP3A4, which could theoretically increase the bioavailability of oral midazolam. This may cancel out the decrease in availability caused by induction of hepatic CYP3A4, such that overall plasma levels after oral administration of midazolam are not affected by echinacea.

Likelihood Possible Evidence B
Warfarin (Coumadin)

Echinacea seems to increase the clearance of warfarin, although the effect may not be clinically significant.
Preliminary clinical research in healthy male volunteers suggests that taking echinacea increases the clearance of the active S-isomer of warfarin after a single dose of warfarin, but there was not a clinically significant effect on the INR.

Likelihood Possible Evidence B
Echinacea full monograph & interactions

Peppermint5 drug types · 796 drugs

Cyclosporine (Neoral, Sandimmune)

Theoretically, peppermint oil might increase the levels and adverse effects of cyclosporine.
In animal research, peppermint oil inhibits cyclosporine metabolism and increases cyclosporine levels. Inhibition of cytochrome P450 3A4 (CYP3A4) may be partially responsible for this interaction. An interaction between peppermint oil and cyclosporine has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2C19 (Cyp2C19) Substrates

Theoretically, peppermint might increase the levels of CYP2C19 substrates.
In vitro research shows that peppermint oil inhibits CYP2C19. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2C9 (Cyp2C9) Substrates

Theoretically, peppermint might increase the levels of CYP2C9 substrates.
In vitro research shows that peppermint oil inhibits CYP2C9. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, peppermint might increase the levels of CYP3A4 substrates.
Clinical research in healthy volunteers shows that a single dose of peppermint oil 600 mg inhibits CYP3A4 enzymes and increases the AUC of felodipine, a CYP3A4 substrate. However, in vitro research suggests that peppermint oil only inhibits CYP3A4 at very high concentrations.

Likelihood Possible Evidence B
Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, peppermint might increase the levels of CYP1A2 substrates.
In vitro and animal research shows that peppermint oil and peppermint leaf inhibit CYP1A2. However, in clinical research, peppermint tea did not significantly affect the metabolism of caffeine, a CYP1A2 substrate. It is possible that the 6-day duration of treatment may have been too short to identify a difference.

Likelihood Possible Evidence B
Peppermint full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Citrigen, from the product label.

Genestra Brands

Name
Seroyal USA
City
Pittsburgh
State
PA
ZipCode
15275
Phone Number
1-888-737-6925
Web Address
seroyal.com
Pharmacist Counseling Corner

Citrigen by Genestra Brands: Common Questions

Does Citrigen by Genestra Brands interact with any medications?
Yes. Based on its ingredients, Citrigen has a known interaction with 1,476 medications, including 785 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Citrigen contains 4 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Is peppermint in this product safe during pregnancy or while breastfeeding?
Peppermint is rated likely safe during both pregnancy and lactation. However, if you're pregnant or nursing, it's always wise to check with your doctor or pharmacist before starting any supplement.
Can I use this if I'm taking a seizure medication?
The green tea in this product contains caffeine, which animal studies suggest may reduce the effectiveness of seizure drugs like phenytoin, valproate, ethosuximide, and felbamate—though this hasn't been confirmed in humans. Talk to your doctor or pharmacist before using it with a seizure medication.
What does echinacea do in this formula?
Echinacea is included for its immune-stimulating effects. However, the evidence supporting its effectiveness for specific health conditions is currently insufficient to rate. It does carry a moderate risk of raising caffeine levels and affecting drug metabolism.
Is the grapefruit extract in this product the same as eating a grapefruit?
No. The product contains a concentrated extract, not whole fruit. While eating grapefruit as food is generally safe, concentrated extracts haven't been as thoroughly studied for safety. The extract can still affect how your body metabolizes many medications.
What are the most common side effects I might experience?
Peppermint may cause abdominal pain, heartburn, nausea, diarrhea, dry mouth, or belching. Green tea can cause bloating, constipation, diarrhea, nausea, or indigestion—especially at higher doses. Echinacea may cause stomach upset, nausea, rashes, or diarrhea. Allergic reactions are rare but possible, particularly in people sensitive to ragweed.
Will this product work for my digestive issues?
Peppermint, one of the four ingredients, is rated likely effective for irritable bowel syndrome and possibly effective for indigestion and some types of nausea. Whether the full formula helps depends on your specific condition—your pharmacist or doctor can advise whether Citrigen is appropriate for you.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if Citrigen is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Citrigen label
Go deeper

The Full Monographs Behind Citrigen’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Peppermint

Interacts with 796 drugs

Peppermint is a popular herb with the best evidence supporting enteric-coated peppermint oil for easing IBS symptoms. It is generally well tolerated for most adults, but it can cause heartbu...

Read the full Peppermint monograph → Herb & supplement monograph

Green Tea

Interacts with 1,293 drugs

Green tea is a popular beverage rich in antioxidants called catechins, and drinking it in normal amounts is considered safe for most people. Concentrated green tea extracts are a different s...

Read the full Green Tea monograph → Herb & supplement monograph

Echinacea

Interacts with 816 drugs

Echinacea is a popular herb taken to help prevent or shorten the common cold, but study results are mixed and the overall benefit appears small at best. It is generally well tolerated for sh...

Read the full Echinacea monograph → Herb & supplement monograph

Grapefruit

Interacts with 990 drugs

Grapefruit is a nutritious citrus fruit rich in vitamin C and other nutrients, and it is generally safe to eat. However, grapefruit is famous for serious interactions with many prescription...

Read the full Grapefruit monograph →
Sources

Sources & How We Checked

Citrigen's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 468 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Peppermint 41 references
  1. Liu JH, Chen GH, Yeh HZ, et al. Enteric-coated peppermint-oil capsules in the treatment of irritable bowel syndrome: a prospective, randomized trial. J Gastroenterol 1997;32:765-8. PubMed
  2. Pittler MH, Ernst E. Peppermint oil for irritable bowel syndrome: a critical review and metaanalysis. Am J Gastroenterol 1998;93:1131-5. PubMed
  3. Kline RM, Kline JJ, Di Palma J, Barbero GJ. Enteric-coated, pH-dependent peppermint oil capsules for the treatment of irritable bowel syndrome in children. J Pediatr 2001;138:125-8. PubMed
  4. Madisch A, Heydenreich CJ, Wieland V, et al. Treatment of functional dyspepsia with a fixed peppermint oil and caraway oil combination preparation as compared to cisapride. A multicenter, reference-controlled, double-blind equivalence study. Arzneimittel
  5. May B, Kuntz HD, Kieser M, Kohler S. Efficacy of a fixed peppermint oil/caraway oil combination in non-ulcer dyspepsia. Arzneimittelforschung 1996;46:1149-53.
  6. Micklefield GH, Greving I, May B. Effects of peppermint oil and caraway oil on gastroduodenal motility. Phytother Res 2000;14:20-3. DOI
  7. Morton CA, Garioch J, Todd P, et al. Contact sensitivity to menthol and peppermint in patients with intra-oral symptoms. Contact Dermatitis 1995;32:281-4. PubMed
  8. May B, Kohler S, Schneider B. Efficacy and tolerability of a fixed combination of peppermint oil and caraway oil in patients suffering from functional dyspepsia. Aliment Pharmacol Ther 2000;14:1671-7. PubMed
  9. Nash P, Gould SR, Bernardo DE. Peppermint oil does not relieve the pain of irritable bowel syndrome. Br J Clin Pract 1986;40:292-3. DOI
  10. Rees WD, Evans BK, Rhodes J. Treating irritable bowel syndrome with peppermint oil. Br Med J 1979;2:835-6. PubMed
  11. Davies SJ, Harding LM, Baranowski AP. A novel treatment of postherpetic neuralgia using peppermint oil. Clin J Pain 2002;18:200-2. PubMed
  12. Weston CF. Anal burning and peppermint oil. Postgrad Med J 1987;63:717. PubMed
  13. Dresser GK, Wacher V, Wong S, et al. Evaluation of peppermint oil and ascorbyl palmitate as inhibitors of cytochrome P4503A4 activity in vitro and in vivo. Clin Pharmacol Ther 2002;72:247-55. PubMed
  14. Wacher VJ, Wong S, Wong HT. Peppermint oil enhances cyclosporine oral bioavailability in rats: comparison with D-alpha-tocopheryl poly(ethylene glycol 1000) succinate (TPGS) and ketoconazole. J Pharm Sci 2002;91:77-90.
  15. Lawson MJ, Knight RE, Tran K, et al. Failure of enteric-coated peppermint oil in the irritable bowel syndrome: a randomized double-blind crossover study. J Gastroenterol Hepatol 1988;3:235-8. DOI
  16. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
  17. Maliakal PP, Wanwimolruk S. Effect of herbal teas on hepatic drug metabolizing enzymes in rats. J Pharm Pharmacol 2001;53:1323-9. PubMed
  18. Rogers SN, Pahor AL. A form of stomatitis induced by excessive peppermint consumption. Dent Update 1995;22:36-7.
  19. Cappello G, Spezzaferro M, Grossi L, et al. Peppermint oil (Mintoil) in the treatment of irritable bowel syndrome: a prospective double blind placebo-controlled randomized trial. Dig Liver Dis 2007;39:530-6. PubMed
  20. Moghadam BK, Gier R, and Thurlow T. Extensive oral mucosal ulcerations caused by misuse of a commercial mouthwash. Cutis 1999;64:131-134.
  21. Andersen, K. E. Contact allergy to toothpaste flavors. Contact Dermatitis 1978;4(4):195-198. PubMed
  22. Barnard, D. R. Repellency of essential oils to mosquitoes (Diptera: Culicidae). J Med Entomol. 1999;36(5):625-629. PubMed
  23. Tamir, S., Davidovich, Z., Attal, P., and Eliashar, R. Peppermint oil chemical burn. Otolaryngol.Head Neck Surg. 2005;133(5):801-802. PubMed
  24. Kalavala, M., Hughes, T. M., Goodwin, R. G., Anstey, A. V., and Stone, N. M. Allergic contact dermatitis to peppermint foot spray. Contact Dermatitis 2007;57(1):57-58. PubMed
  25. Vermaat, H., van Meurs, T., Rustemeyer, T., Bruynzeel, D. P., and Kirtschig, G. Vulval allergic contact dermatitis due to peppermint oil in herbal tea. Contact Dermatitis 2008;58(6):364-365. PubMed
  26. Merat, S., Khalili, S., Mostajabi, P., Ghorbani, A., Ansari, R., and Malekzadeh, R. The effect of enteric-coated, delayed-release peppermint oil on irritable bowel syndrome. Dig.Dis.Sci. 2010;55(5):1385-1390. PubMed
  27. Tran, A., Pratt, M., and DeKoven, J. Acute allergic contact dermatitis of the lips from peppermint oil in a lip balm. Dermatitis 2010;21(2):111-115. DOI
  28. Hitz, Lindenmuller, I and Lambrecht, J. T. Oral care. Curr Probl.Dermatol 2011;40:107-115.
  29. Shavakhi, A., Ardestani, S. K., Taki, M., Goli, M., and Keshteli, A. H. Premedication with peppermint oil capsules in colonoscopy: a double blind placebo-controlled randomized trial study. Acta Gastroenterol Belg 2012;75(3):349-353.
  30. Lech, Y., Olesen, K. M., Hey, H., Rask-Pedersen, E., Vilien, M., and Ostergaard, O. [Treatment of irritable bowel syndrome with peppermint oil. A double- blind study with a placebo]. Ugeskr.Laeger 10-3-1988;150(40):2388-2389.
  31. Parys, B. T. Chemical burns resulting from contact with peppermint oil mar: a case report. Burns Incl.Therm.Inj. 1983;9(5):374-375. PubMed
  32. Bayat R, Borici-Mazi R. A case of anaphylaxis to peppermint. Allergy Asthma Clin Immunol. 2014;10(1):6. PubMed
  33. Rich G, Shah A, Koloski N, et al. A randomized placebo-controlled trial on the effects of Menthacarin, a proprietary peppermint- and caraway-oil-preparation, on symptoms and quality of life in patients with functional dyspepsia. Neurogastroenterol Motil 2 PubMed
  34. Douros A, Bronder E, Andersohn F, et al. Herb-Induced Liver Injury in the Berlin Case-Control Surveillance Study. Int J Mol Sci 2016;17(1). PubMed
  35. Begas E, Tsioutsiouliti A, Kouvaras E, et al. Effects of peppermint tea consumption on the activities of CYP1A2, CYP2A6, Xanthine Oxidase, N-acetyltranferase-2 and UDP-glucuronosyltransferases-1A1/1A6 in healthy volunteers. Food Chem Toxicol 2017;100:80-9 PubMed
  36. Cash BD, Epstein MS, Shah SM. A Novel Delivery System of Peppermint Oil Is an Effective Therapy for Irritable Bowel Syndrome Symptoms. Dig Dis Sci 2016;61(2):560-71. PubMed
  37. Elsaie LT, El Mohsen AM, Ibrahim IM, Mohey-Eddin MH, Elsaie ML. Effectiveness of topical peppermint oil on symptomatic treatment of chronic pruritus. Clin Cosmet Investig Dermatol 2016;9:333-8. PubMed
  38. Wu J, Xu R, Zhan R, et al. Effective symptomatic treatment for severe and intractable pruritus associated with severe burn-induced hypertrophic scars: A prospective, multicenter, controlled trial. Burns 2016;42(5):1059-66. PubMed
  39. Weerts ZZRM, Masclee AAM, Witteman BJM, et al. Efficacy and safety of peppermint oil in a randomized, double-blind trial of patients with irritable bowel syndrome. Gastroenterology. 2020;158(1):123-136. PubMed
  40. Nee J, Ballou S, Kelley JM, et al. Peppermint Oil Treatment for Irritable Bowel Syndrome: A Randomized Placebo-Controlled Trial. Am J Gastroenterol 2021;116(11):2279-2285. PubMed
  41. Ingrosso MR, Ianiro G, Nee J, et al. Systematic review and meta-analysis: efficacy of peppermint oil in irritable bowel syndrome. Aliment Pharmacol Ther 2022;56(6):932-41. PubMed

See these in context on the Peppermint monograph →

Green Tea 219 references
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Harder S, Fuhr U, Staib AH, Wolff T. Ciprofloxacin-caffeine: a drug interaction established using in vivo and in vitro investigations. Am J Med 1989;87:89S-91S. PubMed
  3. Carbo M, Segura J, De la Torre R, et al. Effect of quinolones on caffeine disposition. Clin Pharmacol Ther 1989;45:234-40. PubMed
  4. Healy DP, Polk RE, Kanawati L, et al. Interaction between oral ciprofloxacin and caffeine in normal volunteers. Antimicrob Agents Chemother 1989;33:474-8. PubMed
  5. Mester R, Toren P, Mizrachi I, et al. Caffeine withdrawal increases lithium blood levels. Biol Psychiatry 1995;37:348-50. PubMed
  6. Jefferson JW. Lithium tremor and caffeine intake: two cases of drinking less and shaking more. J Clin Psychiatry 1988;49:72-3.
  7. Mitscher LA, Mitscher LA, Jung M, Shankel D, et al. Chemoprotection: a review of the potential therapeutic antioxidant properties of green tea (Camellia sinensis) and certain of its constituents. Med Res Rev 1997;17:327-65.
  8. Joeres R, Klinker H, Heusler H, et al. Influence of mexiletine on caffeine elimination. Pharmacol Ther 1987;33:163-9. PubMed
  9. Vahedi K, Domingo V, Amarenco P, Bousser MG. Ischemic stroke in a sportsman who consumed MaHuang extract and creatine monohydrate for bodybuilding. J Neurol Neurosurg Psychiatr 2000;68:112-3.
  10. Wakabayashi K, Kono S, Shinchi K, et al. Habitual coffee consumption and blood pressure: A study of self-defense officials in Japan. Eur J Epidemiol 1998;14:669-73. PubMed
  11. Hodgson JM, Puddey IB, Burke V, et al. Effects on blood pressure of drinking green and black tea. J Hypertens 1999;17:457-63. PubMed
  12. Booth SL, Madabushi HT, Davidson KW, et al. Tea and coffee brews are not dietary sources of vitamin K-1 (phylloquinone). J Am Diet Assoc 1995;95:82-3. PubMed
  13. Lou FQ, Zhang MF, Zhang XG, et al. A study on tea-pigment in prevention of atherosclerosis. Chin Med J (Engl) 1989;102:579-83.
  14. Graham HN. Green tea composition, consumption, and polyphenol chemistry. Prev Med 1992;21:334-50. PubMed
  15. Rapuri PB, Gallagher JC, Kinyamu HK, Ryschon KL. Caffeine intake increases the rate of bone loss in elderly women and interacts with vitamin D receptor genotypes. Am J Clin Nutr 2001;74:694-700. PubMed
  16. The National Toxicology Program (NTP). Caffeine. Center for the Evaluation of Risks to Human Reproduction (CERHR). Available at: http://cerhr.niehs.nih.gov/common/caffeine.html.
  17. Klebanoff MA, Levine RJ, DerSimonian R, et al. Maternal serum paraxanthine, a caffeine metabolite, and the risk of spontaneous abortion. N Engl J Med 1999;341:1639-44. PubMed
  18. Eskenazi B. Caffeine—filtering the facts. N Engl J Med 1999;341:1688-9. PubMed
  19. Fernandes O, Sabharwal M, Smiley T, et al. Moderate to heavy caffeine consumption during pregnancy and relationship to spontaneous abortion and abnormal fetal growth: a meta-analysis. Reprod Toxicol 1998;12:435-44. PubMed
  20. Pollock BG, Wylie M, Stack JA, et al. Inhibition of caffeine metabolism by estrogen replacement therapy in postmenopausal women. J Clin Pharmacol 1999;39:936-40. PubMed
  21. Dews PB, Curtis GL, Hanford KJ, O'Brien CP. The frequency of caffeine withdrawal in a population-based survey and in a controlled, blinded pilot experiment. J Clin Pharmacol 1999;39:1221-32. PubMed
  22. FDA. Proposed rule: dietary supplements containing ephedrine alkaloids. Available at: www.verity.fda.gov (Accessed 25 January 2000).
  23. Weisburger JH. Tea and health: the underlying mechanisms. Proc Soc Exp Biol Med 1999;220:271-5. PubMed
  24. Taylor JR, Wilt VM. Probable antagonism of warfarin by green tea. Ann Pharmacother 1999;33:426-8. PubMed
  25. Briggs GB, Freeman RK, Yaffe SJ. Drugs in Pregnancy and Lactation. 5th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 1998.
  26. Hagg S, Spigset O, Mjorndal T, Dahlqvist R. Effect of caffeine on clozapine pharmacokinetics in healthy volunteers. Br J Clin Pharmacol 2000;49:59-63. PubMed
  27. Watson JM, Jenkins EJ, Hamilton P, et al. Influence of caffeine on the frequency and perception of hypoglycemia in free-living patients with type 1 diabetes. Diabetes Care 2000;23:455-9. PubMed
  28. Lloyd T, Johnson-Rollings N, Eggli DF, et al. Bone status among postmenopausal women with different habitual caffeine intakes: a longitudinal investigation. J Am Coll Nutr 2000;19:256-61. PubMed
  29. American Academy of Pediatrics. The transfer of drugs and other chemicals into human milk. Pediatrics 2001;108:776-89. PubMed
  30. Heck AM, DeWitt BA, Lukes AL. Potential interactions between alternative therapies and warfarin. Am J Health Syst Pharm 2000;57:1221-7. DOI
  31. Sinclair CJ, Geiger JD. Caffeine use in sports. A pharmacological review. J Sports Med Phys Fitness 2000;40:71-9.
  32. Haller CA, Benowitz NL. Adverse cardiovascular and central nervous system events associated with dietary supplements containing ephedra alkaloids. N Engl J Med 2000;343:1833-8. PubMed
  33. Ali M, Afzal M. A potent inhibitor of thrombin stimulated platelet thromboxane formation from unprocessed tea. Prostaglandins Leukot Med 1987;27:9-13. PubMed
  34. Ardlie NG, Glew G, Schultz BG, Schwartz CJ. Inhibition and reversal of platelet aggregation by methyl xanthines. Thromb Diath Haemorrh 1967;18:670-3. DOI
  35. Ferrini RL, Barrett-Connor E. Caffeine intake and endogenous sex steroid levels in postmenopausal women. The Rancho Bernardo Study. Am J Epidemiol 1996:144:642-4. PubMed
  36. Pisters KM, Newman RA, Coldman B, et al. Phase I trial of oral green tea extract in adult patients with solid tumors. J Clin Oncol 2001;19:1830-8. PubMed
  37. Haller CA, Jacob P 3rd, Benowitz NL. Pharmacology of ephedra alkaloids and caffeine after single-dose dietary supplement use. Clin Pharmacol Ther 2002;71:421-32. PubMed
  38. Bell DG, Jacobs I, Ellerington K. Effect of caffeine and ephedrine ingestion on anaerobic exercise performance. Med Sci Sports Exerc 2001;33:1399-403. PubMed
  39. Horner NK, Lampe JW. Potential mechanisms of diet therapy for fibrocystic breast conditions show inadequate evidence of effectiveness. J Am Diet Assoc 2000;100:1368-80. PubMed
  40. Bracken MB, Triche EW, Belanger K, et al. Association of maternal caffeine consumption with decrements in fetal growth. Am J Epidemiol 2003;157:456-66.. PubMed
  41. McGowan JD, Altman RE, Kanto WP Jr. Neonatal withdrawal symptoms after chronic maternal ingestion of caffeine. South Med J 1988;81:1092-4.. PubMed
  42. Nehlig A, Debry G. Consequences on the newborn of chronic maternal consumption of coffee during gestation and lactation: a review. J Am Coll Nutr 1994;13:6-21.. PubMed
  43. Massey LK. Is caffeine a risk factor for bone loss in the elderly? Am J Clin Nutr 2001;74:569-70. PubMed
  44. Kockler DR, McCarthy MW, Lawson CL. Seizure activity and unresponsiveness after hydroxycut ingestion. Pharmacotherapy 2001;21:647-51.. PubMed
  45. Nix D, Zelenitsky S, Symonds W, et al. The effect of fluconazole on the pharmacokinetics of caffeine in young and elderly subjects. Clin Pharmacol Ther 1992;51:183. DOI
  46. Ahn WS, Yoo J, Huh SW, et al. Protective effects of green tea extracts (polyphenon E and EGCG) on human cervical lesions. Eur J Cancer Prev 2003;12:383-90. PubMed
  47. Infante S, Baeza ML, Calvo M, et al. Anaphylaxis due to caffeine. Allergy 2003;58:681-2. PubMed
  48. Massey LK, Whiting SJ. Caffeine, urinary calcium, calcium metabolism and bone. J Nutr 1993;123:1611-4. PubMed
  49. Shirai T, Hayakawa H, Akiyama J, et al. Food allergy to green tea. J Allergy Clin Immunol 2003;112:805-6. PubMed
  50. Jatoi A, Ellison N, Burch PA, et al. A phase II trial of green tea in the treatment of patients with androgen independent metastatic prostate carcinoma. Cancer 2003;97:1442-6.. PubMed
  51. Nawrot P, Jordan S, Eastwood J, et al. Effects of caffeine on human health. Food Addit Contam 2003;20:1-30. PubMed
  52. May DC, Jarboe CH, VanBakel AB, Williams WM. Effects of cimetidine on caffeine disposition in smokers and nonsmokers. Clin Pharmacol Ther 1982;31:656-61. PubMed
  53. Brown NJ, Ryder D, Branch RA. A pharmacodynamic interaction between caffeine and phenylpropanolamine. Clin Pharmacol Ther 1991;50:363-71. PubMed
  54. Sanderink GJ, Bournique B, Stevens J, et al. Involvement of human CYP1A isoenzymes in the metabolism and drug interactions of riluzole in vitro. Pharmacol Exp Ther 1997;282:1465-72. DOI
  55. Wahllander A, Paumgartner G. Effect of ketoconazole and terbinafine on the pharmacokinetics of caffeine in healthy volunteers. Eur J Clin Pharmacol 1989;37:279-83. PubMed
  56. Carrillo JA, Benitez J. Clinically significant pharmacokinetic interactions between dietary caffeine and medications. Clin Pharmacokinet 2000;39:127-53. PubMed
  57. Underwood DA. Which medications should be held before a pharmacologic or exercise stress test? Cleve Clin J Med 2002;69:449-50. PubMed
  58. Aqel RA, Zoghbi GJ, Trimm JR, et al. Effect of caffeine administered intravenously on intracoronary-administered adenosine-induced coronary hemodynamics in patients with coronary artery disease. Am J Cardiol 2004;93:343-6. PubMed
  59. Zheng XM, Williams RC. Serum caffeine levels after 24-hour abstention: clinical implications on dipyridamole (201)Tl myocardial perfusion imaging. J Nucl Med Technol 2002;30:123-7.
  60. Institute of Medicine. Caffeine for the Sustainment of Mental Task Performance: Formulations for Military Operations. Washington, DC: National Academy Press, 2001. Available at: http://books.nap.edu/books/0309082587/html/index.html. DOI
  61. Dews PB, O'Brien CP, Bergman J. Caffeine: behavioral effects of withdrawal and related issues. Food Chem Toxicol 2002;40:1257-61. PubMed
  62. Beach CA, Mays DC, Guiler RC, et al. Inhibition of elimination of caffeine by disulfiram in normal subjects and recovering alcoholics. Clin Pharmacol Ther 1986;39:265-70. PubMed
  63. Yang YC, Lu FH, Wu JS, et al. The protective effect of habitual tea consumption on hypertension. Arch Intern Med 2004 26;164:1534-40. PubMed
  64. Son DJ, Cho MR, Jin YR, et al. Antiplatelet effect of green tea catechins: a possible mechanism through arachidonic acid pathway. Prostaglandins Leukot Essent Fatty Acids 2004;71:25-31. PubMed
  65. Juliano LM, Griffiths RR. A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features. Psychopharmacology (Berl) 2004;176:1-29. PubMed
  66. Winkelmayer WC, Stampfer MJ, Willett WC, Curhan GC. Habitual caffeine intake and the risk of hypertension in women. JAMA 2005;294:2330-5. PubMed
  67. Raaska K, Raitasuo V, Laitila J, Neuvonen PJ. Effect of caffeine-containing versus decaffeinated coffee on serum clozapine concentrations in hospitalised patients. Basic Clin Pharmacol Toxicol 2004;94:13-8. DOI
  68. Forrest WH Jr, Bellville JW, Brown BW Jr. The interaction of caffeine with pentobarbital as a nighttime hypnotic. Anesthesiology 1972;36:37-41. PubMed
  69. Lake CR, Rosenberg DB, Gallant S, et al. Phenylpropanolamine increases plasma caffeine levels. Clin Pharmacol Ther 1990;47:675-85. PubMed
  70. Bonkovsky HL. Hepatotoxicity associated with supplements containing Chinese green tea (Camellia sinensis). Ann Intern Med 2006;144:68-71.
  71. Gloro R, Hourmand-Ollivier I, Mosquet B, et al. Fulminant hepatitis during self-medication with hydroalcoholic extract of green tea. Eur J Gastroenterol Hepatol 2005;17:1135-7. PubMed
  72. Donovan JL, Chavin KD, Devane CL, et al. Green tea (Camellia sinensis) extract does not alter cytochrome P450 3A4 or 2D6 activity in healthy volunteers. Drug Metab Dispos 2004;32:906-8. PubMed
  73. Chu KO, Wang CC, Chu CY, et al. Pharmacokinetic studies of green tea catechins in maternal plasma and fetuses in rats. J Pharm Sci 2006;95:1372-81. PubMed
  74. Isbrucker RA, Edwards JA, Wolz E, et al. Safety studies on epigallocatechin gallate (EGCG) preparations. Part 3: teratogenicity and reproductive toxicity studies in rats. Food Chem Toxicol 2006;44:651-61. PubMed
  75. Navarro-Peran E, Cabezas-Herrera J, Garcia-Canovas F, et al. The antifolate activity of tea catechins. Cancer Res 2005;65:2059-64. PubMed
  76. Jimenez-Saenz M, Martinez-Sanchez, MDC. Acute hepatitis associated with the use of green tea infusions. J Hepatol 2006;44:616-9. PubMed
  77. Bradley Pharmaceuticals. Veregen Prescribing Information. October 2006.
  78. Correa A, Stolley A, Liu Y. Prenatal tea consumption and risks of anencephaly and spina bifida. Ann Epidemiol 2000;10:476-7. PubMed
  79. Weng X, Odouli R, Li DK. Maternal caffeine consumption during pregnancy and the risk of miscarriage: a prospective cohort study. Am J Obstet Gynecol 2008;198:279.e1-8. PubMed
  80. Savitz DA, Chan RL, Herring AH, et al. Caffeine and miscarriage risk. Epidemiology 2008;19:55-62. PubMed
  81. Golden ED, Lam PY, Kardosh A, et al. Green tea polyphenols block the anticancer effects of bortezomib and other boronic acid-based proteasome inhibitors. Blood 2009;113:5927-37. PubMed
  82. Misaka S, Yatabe J, Muller F, et al. Green Tea Ingestion Greatly Reduces Plasma Concentrations of Nadolol in Healthy Subjects. Clin Pharmacol Ther 2014. [Epub ahead of print]. PubMed
  83. Roth M, Timmermann BN, Hagenbuch B. Interactions of green tea catechins with organic anion-transporting polypeptides. Drug Metab Dispos 2011;39:920-6. PubMed
  84. Kato Y, Miyazaki T, Kano T, et al. Involvement of influx and efflux transport systems in gastrointestinal absorption of celiprolol. J Pharm Sci 2009;98:2529-39. PubMed
  85. Chan, H. T., So, L. T., Li, S. W., Siu, C. W., Lau, C. P., and Tse, H. F. Effect of herbal consumption on time in therapeutic range of warfarin therapy in patients with atrial fibrillation. J.Cardiovasc.Pharmacol. 2011;58(1):87-90. PubMed
  86. Nishikawa, M., Ariyoshi, N., Kotani, A., Ishii, I., Nakamura, H., Nakasa, H., Ida, M., Nakamura, H., Kimura, N., Kimura, M., Hasegawa, A., Kusu, F., Ohmori, S., Nakazawa, K., and Kitada, M. Effects of continuous ingestion of green tea or grape seed extrac
  87. Shet, M. S., McPhaul, M., Fisher, C. W., Stallings, N. R., and Estabrook, R. W. Metabolism of the antiandrogenic drug (Flutamide) by human CYP1A2. Drug Metab Dispos. 1997;25(11):1298-1303.
  88. Staib, A. H., Stille, W., Dietlein, G., Shah, P. M., Harder, S., Mieke, S., and Beer, C. Interaction between quinolones and caffeine. Drugs 1987;34 Suppl 1:170-174. PubMed
  89. Stille, W., Harder, S., Mieke, S., Beer, C., Shah, P. M., Frech, K., and Staib, A. H. Decrease of caffeine elimination in man during co-administration of 4-quinolones. J.Antimicrob.Chemother. 1987;20(5):729-734. PubMed
  90. Fuhr, U., Strobl, G., Manaut, F., Anders, E. M., Sorgel, F., Lopez-de-Brinas, E., Chu, D. T., Pernet, A. G., Mahr, G., Sanz, F., and . Quinolone antibacterial agents: relationship between structure and in vitro inhibition of the human cytochrome P450 isof
  91. Kot, M. and Daniel, W. A. Effect of diethyldithiocarbamate (DDC) and ticlopidine on CYP1A2 activity and caffeine metabolism: an in vitro comparative study with human cDNA-expressed CYP1A2 and liver microsomes. Pharmacol Rep. 2009;61(6):1216-1220. PubMed
  92. Gasior, M., Borowicz, K., Buszewicz, G., Kleinrok, Z., and Czuczwar, S. J. Anticonvulsant activity of phenobarbital and valproate against maximal electroshock in mice during chronic treatment with caffeine and caffeine discontinuation. Epilepsia 1996;37(3 PubMed
  93. Jankiewicz, K., Chroscinska-Krawczyk, M., Blaszczyk, B., and Czuczwar, S. J. [Caffeine and antiepileptic drugs: experimental and clinical data]. Przegl.Lek. 2007;64(11):965-967.
  94. Luszczki, J. J., Zuchora, M., Sawicka, K. M., Kozinska, J., and Czuczwar, S. J. Acute exposure to caffeine decreases the anticonvulsant action of ethosuximide, but not that of clonazepam, phenobarbital and valproate against pentetrazole-induced seizures i
  95. Chroscinska-Krawczyk, M., Jargiello-Baszak, M., Walek, M., Tylus, B., and Czuczwar, S. J. Caffeine and the anticonvulsant potency of antiepileptic drugs: experimental and clinical data. Pharmacol.Rep. 2011;63(1):12-18. PubMed
  96. Vaz, J., Kulkarni, C., David, J., and Joseph, T. Influence of caffeine on pharmacokinetic profile of sodium valproate and carbamazepine in normal human volunteers. Indian J.Exp.Biol. 1998;36(1):112-114.
  97. Gasior, M., Swiader, M., Przybylko, M., Borowicz, K., Turski, W. A., Kleinrok, Z., and Czuczwar, S. J. Felbamate demonstrates low propensity for interaction with methylxanthines and Ca2+ channel modulators against experimental seizures in mice. Eur.J Phar PubMed
  98. Mohiuddin, M., Azam, A. T., Amran, M. S., and Hossain, M. A. In vive effects of gliclazide and metformin on the plasma concentration of caffeine in healthy rats. Pak.J Biol Sci 5-1-2009;12(9):734-737.
  99. Mays, D. C., Camisa, C., Cheney, P., Pacula, C. M., Nawoot, S., and Gerber, N. Methoxsalen is a potent inhibitor of the metabolism of caffeine in humans. Clin.Pharmacol.Ther. 1987;42(6):621-626. PubMed
  100. Wojcikowski, J. and Daniel, W. A. Perazine at therapeutic drug concentrations inhibits human cytochrome P450 isoenzyme 1A2 (CYP1A2) and caffeine metabolism--an in vitro study. Pharmacol Rep. 2009;61(5):851-858. PubMed
  101. Daniel, W. A., Syrek, M., Rylko, Z., and Kot, M. Effects of phenothiazine neuroleptics on the rate of caffeine demethylation and hydroxylation in the rat liver. Pol.J Pharmacol 2001;53(6):615-621.
  102. Norager, C. B., Jensen, M. B., Weimann, A., and Madsen, M. R. Metabolic effects of caffeine ingestion and physical work in 75-year old citizens. A randomized, double-blind, placebo-controlled, cross-over study. Clin Endocrinol (Oxf) 2006;65(2):223-228. PubMed
  103. Wang, X. and Yeung, J. H. Effects of the aqueous extract from Salvia miltiorrhiza Bunge on caffeine pharmacokinetics and liver microsomal CYP1A2 activity in humans and rats. J Pharm Pharmacol 2010;62(8):1077-1083.
  104. Kot M, Daniel WA. Caffeine as a marker substrate for testing cytochrome P450 activity in human and rat. Pharmacol Rep 2008;60:789-97.
  105. Kjaerstad MB, Nielsen F, Nohr-Jensen L, et al. Systemic uptake of miconazole during vaginal suppository use and effect on CYP1A2 and CYP3A4 associated enzyme activities in women. Eur J Clin Pharmacol 2010;66:1189-97. PubMed
  106. Goh BC, Reddy NJ, Dandamudi UB, et al. An evaluation of the drug interaction potential of pazopanib, an oral vascular endothelial growth factor receptor tyrosine kinase inhibitor, using a modified Cooperstown 5+1 cocktail in patients with advanced solid t
  107. Chen Y, Kang Z, Yan J, et al. Liu wei di huang wan, a well-known traditional Chinese medicine induces CYP1A2 while suppressing CYP2A6 and N-acetyltransferase 2 acivities in man. J Ethnopharmacol 2010;132:213-8.
  108. Suzuki S, Murayama Y, Sugiyama E, et al. Estimating pediatric doses of drugs metabolized by cytochrome P450 (CYP) isozymes, based on physiological liver development and serum protein levels. Yakugaku Zasshi 2010;130:613-20. PubMed
  109. Chien CF, Wu YT, Lee WC, et al. Herb-drug interaction of Andrographis paniculata extract and andrographolide on the pharmacokinetics of theophylline in rats. Chem Biol Interact 2010;184:458-65. PubMed
  110. Mills BM, Zaya MJ, Walters RR, et al. Current cytochrome P450 phenotyping methods applied to metabolic drug -drug interaction prediction in dogs. Drug Metab Dispos 2010;38:396-404. PubMed
  111. Turpault S, Brian W, Van Horn R, et al. Pharmacokinetic assessment of a five-probe cocktail for CYPs 1A2, 2C9, 2C19, 2D6, and 3A. Br J Clin Pharmacol 2009;68:928-35. PubMed
  112. Filimonova AA, Ziganshina LE, Ziganshin AU, Chichirov AA. On the possibility of patient phenotyping on the basis of cytochrome p-450 1A2 isoenzyme activity using caffeine as the test substrate. Eksp Klin Farmakol 2009;72:61-5.
  113. Jenkins J, Williams D, Deng Y, et al. Eltrombopag, an oral thrombopoietin receptor agonist, has no impact on the pharmacokinetic profile of probe drugs for cytochrome P450 isoenzymes CYP3A4, CYP1A2, CYP2C9 and CYP2C19 in healthy men: a cocktail analysis.
  114. Chow, H. H., Cai, Y., Hakim, I. A., Crowell, J. A., Shahi, F., Brooks, C. A., Dorr, R. T., Hara, Y., and Alberts, D. S. Pharmacokinetics and safety of green tea polyphenols after multiple-dose administration of epigallocatechin gallate and polyphenon E i
  115. Gross, G., Meyer, K. G., Pres, H., Thielert, C., Tawfik, H., and Mescheder, A. A randomized, double-blind, four-arm parallel-group, placebo-controlled Phase II/III study to investigate the clinical efficacy of two galenic formulations of Polyphenon E in
  116. Stockfleth, E., Beti, H., Orasan, R., Grigorian, F., Mescheder, A., Tawfik, H., and Thielert, C. Topical Polyphenon E in the treatment of external genital and perianal warts: a randomized controlled trial. Br.J Dermatol. 2008;158(6):1329-1338.
  117. Smits, P., Temme, L., and Thien, T. The cardiovascular interaction between caffeine and nicotine in humans. Clin Pharmacol Ther 1993;54(2):194-204. PubMed
  118. MacKenzie, T., Comi, R., Sluss, P., Keisari, R., Manwar, S., Kim, J., Larson, R., and Baron, J. A. Metabolic and hormonal effects of caffeine: randomized, double-blind, placebo-controlled crossover trial. Metabolism 2007;56(12):1694-1698. PubMed
  119. Lopez-Garcia, E., Rodriguez-Artalejo, F., Rexrode, K. M., Logroscino, G., Hu, F. B., and van Dam, R. M. Coffee consumption and risk of stroke in women. Circulation 3-3-2009;119(8):1116-1123. PubMed
  120. Zhang, W., Lopez-Garcia, E., Li, T. Y., Hu, F. B., and van Dam, R. M. Coffee consumption and risk of cardiovascular diseases and all-cause mortality among men with type 2 diabetes. Diabetes Care 2009;32(6):1043-1045. PubMed
  121. Moisey, L. L., Robinson, L. E., and Graham, T. E. Consumption of caffeinated coffee and a high carbohydrate meal affects postprandial metabolism of a subsequent oral glucose tolerance test in young, healthy males. Br.J Nutr. 2010;103(6):833-841. PubMed
  122. Chroscinska-Krawczyk, M., Ratnaraj, N., Patsalos, P. N., and Czuczwar, S. J. Effect of caffeine on the anticonvulsant effects of oxcarbazepine, lamotrigine and tiagabine in a mouse model of generalized tonic-clonic seizures. Pharmacol Rep. 2009;61(5):819 PubMed
  123. Simmonds, M. J., Minahan, C. L., and Sabapathy, S. Caffeine improves supramaximal cycling but not the rate of anaerobic energy release. Eur.J Appl Physiol 2010;109(2):287-295. PubMed
  124. Buscemi, S., Verga, S., Batsis, J. A., Donatelli, M., Tranchina, M. R., Belmonte, S., Mattina, A., Re, A., and Cerasola, G. Acute effects of coffee on endothelial function in healthy subjects. Eur.J Clin Nutr. 2010;64(5):483-489. PubMed
  125. Rigato, I., Blarasin, L., and Kette, F. Severe hypokalemia in 2 young bicycle riders due to massive caffeine intake. Clin J Sport Med. 2010;20(2):128-130. PubMed
  126. Ernest, D., Chia, M., and Corallo, C. E. Profound hypokalaemia due to Nurofen Plus and Red Bull misuse. Crit Care Resusc. 2010;12(2):109-110. DOI
  127. Conen, D., Chiuve, S. E., Everett, B. M., Zhang, S. M., Buring, J. E., and Albert, C. M. Caffeine consumption and incident atrial fibrillation in women. Am J Clin Nutr 2010;92(3):509-514. PubMed
  128. Reis, J. P., Loria, C. M., Steffen, L. M., Zhou, X., van, Horn L., Siscovick, D. S., Jacobs, D. R., Jr., and Carr, J. J. Coffee, decaffeinated coffee, caffeine, and tea consumption in young adulthood and atherosclerosis later in life: the CARDIA study. A PubMed
  129. Clausen, T. Hormonal and pharmacological modification of plasma potassium homeostasis. Fundam.Clin Pharmacol 2010;24(5):595-605. PubMed
  130. Gronroos, N. N. and Alonso, A. Diet and risk of atrial fibrillation - epidemiologic and clinical evidence -. Circ.J 2010;74(10):2029-2038. PubMed
  131. Perera, V., Gross, A. S., and McLachlan, A. J. Caffeine and paraxanthine HPLC assay for CYP1A2 phenotype assessment using saliva and plasma. Biomed.Chromatogr. 2010;24(10):1136-1144. PubMed
  132. Orozco-Gregorio, H., Mota-Rojas, D., Bonilla-Jaime, H., Trujillo-Ortega, M. E., Becerril-Herrera, M., Hernandez-Gonzalez, R., and Villanueva-Garcia, D. Effects of administration of caffeine on metabolic variables in neonatal pigs with peripartum asphyxia PubMed
  133. Izzo, A. A. and Ernst, E. Interactions between herbal medicines and prescribed drugs: an updated systematic review. Drugs 2009;69(13):1777-1798. PubMed
  134. Laurie, S. A., Miller, V. A., Grant, S. C., Kris, M. G., and Ng, K. K. Phase I study of green tea extract in patients with advanced lung cancer. Cancer Chemother.Pharmacol. 2005;55(1):33-38. PubMed
  135. Chiu, A. E., Chan, J. L., Kern, D. G., Kohler, S., Rehmus, W. E., and Kimball, A. B. Double-blinded, placebo-controlled trial of green tea extracts in the clinical and histologic appearance of photoaging skin. Dermatol Surg. 2005;31(7 Pt 2):855-860. PubMed
  136. Javaid, A. and Bonkovsky, H. L. Hepatotoxicity due to extracts of Chinese green tea (Camellia sinensis): a growing concern. J Hepatol 2006;45(2):334-335. PubMed
  137. Martinez-Sierra, C., Rendon, Unceta P., and Martin, Herrera L. [Acute hepatitis after green tea ingestion]. Med Clin (Barc.) 6-17-2006;127(3):119.
  138. Molinari, M., Watt, K. D., Kruszyna, T., Nelson, R., Walsh, M., Huang, W. Y., Nashan, B., and Peltekian, K. Acute liver failure induced by green tea extracts: case report and review of the literature. Liver Transpl. 2006;12(12):1892-1895. PubMed
  139. Chow, H. H., Hakim, I. A., Vining, D. R., Crowell, J. A., Cordova, C. A., Chew, W. M., Xu, M. J., Hsu, C. H., Ranger-Moore, J., and Alberts, D. S. Effects of repeated green tea catechin administration on human cytochrome P450 activity. Cancer Epidemiol.B PubMed
  140. Federico, A., Tiso, A., and Loguercio, C. A case of hepatotoxicity caused by green tea. Free Radic.Biol Med 8-1-2007;43(3):474. PubMed
  141. Sarma, D. N., Barrett, M. L., Chavez, M. L., Gardiner, P., Ko, R., Mahady, G. B., Marles, R. J., Pellicore, L. S., Giancaspro, G. I., and Low, Dog T. Safety of green tea extracts : a systematic review by the US Pharmacopeia. Drug Saf 2008;31(6):469-484. PubMed
  142. Engdal, S. and Nilsen, O. G. In vitro inhibition of CYP3A4 by herbal remedies frequently used by cancer patients. Phytother.Res. 2009;23(7):906-912.
  143. Bergman, J. and Schjott, J. Hepatitis caused by Lotus-f3? Basic Clin Pharmacol.Toxicol. 2009;104(5):414-416. PubMed
  144. Kalus, U., Kiesewetter, H., and Radtke, H. Effect of CYSTUS052 and green tea on subjective symptoms in patients with infection of the upper respiratory tract. Phytother.Res. 2010;24(1):96-100.
  145. Tatti, S., Stockfleth, E., Beutner, K. R., Tawfik, H., Elsasser, U., Weyrauch, P., and Mescheder, A. Polyphenon E: a new treatment for external anogenital warts. Br.J Dermatol. 2010;162(1):176-184.
  146. Tsao, A. S., Liu, D., Martin, J., Tang, X. M., Lee, J. J., El-Naggar, A. K., Wistuba, I., Culotta, K. S., Mao, L., Gillenwater, A., Sagesaka, Y. M., Hong, W. K., and Papadimitrakopoulou, V. Phase II randomized, placebo-controlled trial of green tea extra
  147. Liatsos, G. D., Moulakakis, A., Ketikoglou, I., and Klonari, S. Possible green tea-induced thrombotic thrombocytopenic purpura. Am.J Health Syst.Pharm. 4-1-2010;67(7):531-534. PubMed
  148. Josic, J., Olsson, A. T., Wickeberg, J., Lindstedt, S., and Hlebowicz, J. Does green tea affect postprandial glucose, insulin and satiety in healthy subjects: a randomized controlled trial. Nutr.J. 2010;9:63. PubMed
  149. Miller, R. J., Jackson, K. G., Dadd, T., Mayes, A. E., Brown, A. L., and Minihane, A. M. The impact of the catechol-O-methyltransferase genotype on the acute responsiveness of vascular reactivity to a green tea extract. Br.J.Nutr. 2011;105(8):1138-1144.
  150. Rohde, J., Jacobsen, C., and Kromann-Andersen, H. [Toxic hepatitis triggered by green tea]. Ugeskr.Laeger 1-17-2011;173(3):205-206.
  151. Tzellos, T. G., Sardeli, C., Lallas, A., Papazisis, G., Chourdakis, M., and Kouvelas, D. Efficacy, safety and tolerability of green tea catechins in the treatment of external anogenital warts: a systematic review and meta-analysis. J.Eur.Acad.Dermatol.Ve PubMed
  152. Otera, H., Tada, K., Sakurai, T., Hashimoto, K., and Ikeda, A. Hypersensitivity pneumonitis associated with inhalation of catechin-rich green tea extracts. Respiration 2011;82(4):388-392. PubMed
  153. Yellapu, R. K., Mittal, V., Grewal, P., Fiel, M., and Schiano, T. Acute liver failure caused by 'fat burners' and dietary supplements: a case report and literature review. Can.J.Gastroenterol. 2011;25(3):157-160. PubMed
  154. Karth, A., Holoshitz, N., Kavinsky, C. J., Trohman, R., and McBride, B. F. A case report of atrial fibrillation potentially induced by hydroxycut: a multicomponent dietary weight loss supplement devoid of sympathomimetic amines. J.Pharm.Pract. 2010;23(3) PubMed
  155. Hsu, C. H., Liao, Y. L., Lin, S. C., Tsai, T. H., Huang, C. J., and Chou, P. Does supplementation with green tea extract improve insulin resistance in obese type 2 diabetics? A randomized, double-blind, and placebo-controlled clinical trial. Altern.Med.R
  156. Zheng XX, Xu YL, Li SH, et al. Green tea intake lowers fasting serum total and LDL cholesterol in adults: a meta-analysis of 14 randomized controlled trials. Am.J.Clin.Nutr. 2011;94:601-610. PubMed
  157. Miller, R. J., Jackson, K. G., Dadd, T., Mayes, A. E., Brown, A. L., Lovegrove, J. A., and Minihane, A. M. The impact of the catechol-O-methyltransferase genotype on vascular function and blood pressure after acute green tea ingestion. Mol.Nutr.Food Res.
  158. Bogdanski, P., Suliburska, J., Szulinska, M., Stepien, M., Pupek-Musialik, D., and Jablecka, A. Green tea extract reduces blood pressure, inflammatory biomarkers, and oxidative stress and improves parameters associated with insulin resistance in obese, h
  159. Jurgens, T. M., Whelan, A. M., Killian, L., Doucette, S., Kirk, S., and Foy, E. Green tea for weight loss and weight maintenance in overweight or obese adults. Cochrane.Database.Syst.Rev. 2012;12:CD008650. PubMed
  160. Sakamoto, O., Saita, N., Yamasaki, H., Tamanoi, M., and Ando, M. Pulmonary granulomatosis caused by aspirated green tea. Chest 1994;106(1):308-309. PubMed
  161. Jiménez-Encarnación E, Ríos G, Muñoz-Mirabal A, Vilá LM. Euforia-induced acute hepatitis in a patient with scleroderma. BMJ Case Rep 2012;2012. PubMed
  162. Choi JS, Burm JP. Effects of oral epigallocatechin gallate on the pharmacokinetics of nicardipine in rats. Arch Pharm Res. 2009 Dec;32(12):1721-5. PubMed
  163. Chung JH, Choi DH, Choi JS. Effects of oral epigallocatechin gallate on the oral pharmacokinetics of verapamil in rats. Biopharm Drug Dispos. 2009 Mar;30(2):90-3. PubMed
  164. Crew KD, Brown P, Greenlee H, Bevers TB, Arun B, Hudis C, McArthur HL, Chang J, Rimawi M, Vornik L, Cornelison TL, Wang A, Hibshoosh H, Ahmed A, Terry MB, Santella RM, Lippman SM, Hershman DL. Phase IB randomized, double-blinded, placebo-controlled, dose
  165. Dryden GW, Lam A, Beatty K, Qazzaz HH, McClain CJ. A pilot study to evaluate the safety and efficacy of an oral dose of (-)-epigallocatechin-3-gallate-rich polyphenon E in patients with mild to moderate ulcerative colitis. Inflamm Bowel Dis. 2013 Aug;19(9 PubMed
  166. Gallo E, Maggini V, Berardi M, Pugi A, Notaro R, Talini G, Vannozzi G, Bagnoli S, Forte P, Mugelli A, Annese V, Firenzuoli F, Vannacci A. Is green tea a potential trigger for autoimmune hepatitis? Phytomedicine. 2013 Oct 15;20(13):1186-9. PubMed
  167. Liu K, Zhou R, Wang B, Chen K, Shi LY, Zhu JD, Mi MT. Effect of green tea on glucose control and insulin sensitivity: a meta-analysis of 17 randomized controlled trials. Am J Clin Nutr. 2013 Aug;98(2):340-8. PubMed
  168. Onakpoya I, Spencer E, Heneghan C, Thompson M. The effect of green tea on blood pressure and lipid profile: a systematic review and meta-analysis of randomized clinical trials. Nutr Metab Cardiovasc Dis. 2014 Aug;24:823-36. PubMed
  169. Patel SS, Beer S, Kearney DL, Phillips G, Carter BA. Green tea extract: a potential cause of acute liver failure. World J Gastroenterol. 2013 Aug 21;19(31):5174-7. PubMed
  170. Pillukat MH, Bester C, Hensel A, Lechtenberg M, Petereit F, Beckebaum S, Müller KM, Schmidt HH. Concentrated green tea extract induces severe acute hepatitis in a 63-year-old woman--a case report with pharmaceutical analysis. J Ethnopharmacol. 2014 Aug 8; PubMed
  171. Schönthal AH. Adverse effects of concentrated green tea extracts. Mol Nutr Food Res. 2011 Jun;55(6):874-85. PubMed
  172. Shiraishi M, Haruna M, Matsuzaki M, Ota E, Murayama R, Murashima S. Association between the serum folate levels and tea consumption during pregnancy. Biosci Trends. 2010 Oct;4(5):225-30.
  173. Jang EH, Choi JY, Park CS, Lee SK, Kim CE, Park HJ, Kang JS, Lee JW, Kang JH. Effects of green tea extract administration on the pharmacokinetics of clozapine in rats. J Pharm Pharmacol. 2005 Mar;57(3):311-6. PubMed
  174. Trudel D, Labbé DP, Araya-Farias M, Doyen A, Bazinet L, Duchesne T, Plante M, Grégoire J, Renaud MC, Bachvarov D, Têtu B, Bairati I. A two-stage, single-arm, phase II study of EGCG-enriched green tea drink as a maintenance therapy in women with advanced s
  175. Zheng XX, Xu YL, Li SH, Hui R, Wu YJ, Huang XH. Effects of green tea catechins with or without caffeine on glycemic control in adults: a meta-analysis of randomized controlled trials. Am J Clin Nutr. 2013 Apr;97(4):750-62. PubMed
  176. Caldeira D, Martins C, Alves LB, Pereira H, Ferreira JJ, Costa J. Caffeine does not increase the risk of atrial fibrillation: a systematic review and meta-analysis of observational studies. Heart. 2013;99(19):1383-9. doi: 10.1136/heartjnl-2013-303950. Re PubMed
  177. Cheng M, Hu Z, Lu X, Huang J, Gu D. Caffeine intake and atrial fibrillation incidence: dose response meta-analysis of prospective cohort studies. Can J Cardiol. 2014 Apr;30(4):448-54. doi: 10.1016/j.cjca.2013.12.026. Epub 2014 2. Review. PubMed
  178. van der Hoeven N, Visser I, Schene A, van den Born BJ. Severe hypertension related to caffeinated coffee and tranylcypromine: a case report. Ann Intern Med. 2014 May 6;160(9):657-8. doi: 10.7326/L14-5009-8. No abstract available. PubMed
  179. Dixit S, Stein PK, Dewland TA, Dukes JW, Vittinghoff E, Heckbert SR, Marcus GM. Consumption of Caffeinated Products and Cardiac Ectopy. J Am Heart Assoc. 2016 26;5(1). pii: e002503. doi: 10.1161/JAHA.115.002503. PubMed
  180. Health Canada. Health Product Info Watch. October 2016; 5-6. Available at: http://www.hc-sc.gc.ca/dhp-mps/medeff/bulletin/hpiw-ivps_2016-10-eng.php#a15.
  181. Green Tea Extract-Containing Natural Health Products - Rare Risk of Serious Liver Injury. Recalls & alerts. November 15, 2017. http://healthycanadians.gc.ca/recall-alert-rappel-avis/hc-sc/2017/65100a-eng.php. Accessed November 10, 2017.
  182. Mazzanti G, Di Sotto A, Vitalone A. Hepatotoxicity of green tea: an update. Arch Toxicol. 2015;89(8):1175-91. PubMed
  183. Isomura T, Suzuki S, Origasa H, et al. Liver-related safety assessment of green tea extracts in humans: a systematic review of randomized controlled trials. Eur J Clin Nutr. 2016;70(11):1221-1229. PubMed
  184. Drug Record: Green Tea (Camellia Sinesis). LiverTox: National Institutes of Health, U.S. Department of Health & Human Services, March 2014. https://livertox.nlm.nih.gov//GreenTea.htm. Accessed November 20, 2017.
  185. Yates AA, Erdman JW Jr, Shao A, Dolan LC, Griffiths JC. Bioactive nutrients - Time for tolerable upper intake levels to address safety. Regul Toxicol Pharmacol. 2017;84:94-101. PubMed
  186. Younes M, Aggett P, Aguilar F, et al. EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS). Scientific opinion on the safety of green tea catechins. EFSA Journal 2018;16(4):5239. PubMed
  187. Zuchinali P, Riberio PA, Pimentel M, da Rosa PR, Zimerman LI, Rohde LE. Effect of caffeine on ventricular arrhythmia: a systematic review and meta-analysis of experimental and clinical studies. Europace 2016 Feb;18(2):257-66. PubMed
  188. Dostal AM, Samavat H, Bedell S, et al. The safety of green tea extract supplementation in postmenopausal women at risk for breast cancer: results of the Minnesota Green Tea Trial. Food Chem Toxicol. 2015 Sep;83:26-35. PubMed
  189. Shamekhi Z, Amani R, Habibagahi Z, Namjoyan F, Ghadiri A, Saki Malehi A. A Randomized, Double-blind, Placebo-controlled Clinical Trial Examining the Effects of Green Tea Extract on Systemic Lupus Erythematosus Disease Activity and Quality of Life. Phytoth PubMed
  190. Lagier D, Nee L, Guieu R, et al. Peri-operative oral caffeine does not prevent postoperative atrial fibrillation after heart valve surgery with cardiopulmonary bypass: a randomized controlled clinical trial. Eur J Anaesthesiol. 2018 Apr 26. [Epub ahead of DOI
  191. Voskoboinik A, Kalman JM, Kistler PM. Caffeine and arrhythmias: time to grind the data. JACC: Clin Electrophysiol. 2018;4(4):425-32. PubMed
  192. Chong SJ, Howard KA, Knox C. Hypokalaemia and drinking green tea: a literature review and report of 2 cases. BMJ Case Rep. 2016;2016. pii: bcr2016214425. PubMed
  193. Qiao J, Gu C, Shang W, et al. Effect of green tea on pharmacokinetics of 5-fluorouracil in rats and pharmacodynamics in human cell lines in vitro. Food Chem Toxicol. 2011;49(6):1410-5. PubMed
  194. Abe O, Ono T, Sato H, et al. Role of (-)-epigallocatechin gallate in the pharmacokinetic interaction between nadolol and green tea in healthy volunteers. Eur J Clin Pharmacol 2018;74(6):775-83. doi: 10.1007/s00228-018-2436-2. PubMed
  195. Wikoff D, Welsh BT, Henderson R, et al. Systematic review of the potential adverse effects of caffeine consumption in healthy adults, pregnant women, adolescents, and children. Food Chem Toxicol 2017;109:585-648. PubMed
  196. Nutescu EA, Shapiro NL, Ibrahim S, et al. Warfarin and its interactions with foods, herbs and other dietary supplements. Expert Opin Drug Saf. 2006;5(3):433-51. PubMed
  197. Abdelkawy KS, Abdelaziz RM, Abdelmageed AM, Donia AM, El-Khodary NM. Effects of green tea extract on atorvastatin pharmacokinetics in healthy volunteers. Eur J Drug Metab Pharmacokinet. 2020;45(3):351-360. PubMed
  198. Filippini T, Malavolti M, Borrelli F, et al. Green tea (Camellia sinensis) for the prevention of cancer. Cochrane Database Syst Rev. 2020;3(3):CD005004. PubMed
  199. Huang S, Xu Q, Liu L, et al. Effect of green tea and (-)-epigallocatechin gallate on the pharmacokinetics of rosuvastatin. Curr Drug Metab. 2020. PubMed
  200. Mahmoodi M, Hosseini R, Kazemi A, Ofori-Asenso R, Mazidi M, Mazloomi SM. Effects of green tea or green tea catechin on liver enzymes in healthy individuals and people with nonalcoholic fatty liver disease: A systematic review and meta-analysis of randomiz
  201. Misaka S, Abe O, Ono T, et al. Effects of single green tea ingestion on pharmacokinetics of nadolol in healthy volunteers. Br J Clin Pharmacol. 2020. PubMed
  202. Oketch-Rabah HA, Roe AL, Rider CV, et al. United States Pharmacopeia (USP) comprehensive review of the hepatotoxicity of green tea extracts. Toxicol Rep. 2020;7:386-402. PubMed
  203. Kim TE, Ha N, Kim Y, et al. Effect of epigallocatechin-3-gallate, major ingredient of green tea, on the pharmacokinetics of rosuvastatin in healthy volunteers. Drug Des Devel Ther. 2017;11:1409-1416. PubMed
  204. Misaka S, Ono Y, Uchida A, et al. Impact of green tea catechin ingestion on the pharmacokinetics of lisinopril in healthy volunteers. Clin Transl Sci. 2020. PubMed
  205. Darweesh RS, El-Elimat T, Zayed A, et al. The effect of grape seed and green tea extracts on the pharmacokinetics of imatinib and its main metabolite, N-desmethyl imatinib, in rats. BMC Pharmacol Toxicol. 2020;21(1):77. PubMed
  206. Sonoda J, Ogata K, Yoshikawa N, Sato K, Ikeda R, Shimodozono Y. Impact of green tea intake on the pharmacokinetics of celiprolol in healthy subjects. Int J Clin Pharmacol Ther. 2020. PubMed
  207. Kim S, Park TH, Kim WI, Park S, Kim JH, Cho MK. The effects of green tea on acne vulgaris: A systematic review and meta-analysis of randomized clinical trials. Phytother Res. 2021;35(1):374-383. PubMed
  208. Percevault S, Charpiat B, Lebossé F, Mabrut JY, Vial T, Colom M. Green tea and hepatoxicity: Two case reports. Therapie 2021. PubMed
  209. Kajita N, Miyama S, Kinoshita K, Yoshida K, Narita M. Green tea-induced anaphylaxis: The first pediatric case report. Allergol Int 2021;70(4):507-508. PubMed
  210. Zheng KH, Zhu K, Wactawski-Wende J, et al. Caffeine intake from coffee and tea and invasive breast cancer incidence among postmenopausal women in the Women's Health Initiative. Int J Cancer 2021;149(12):2032-2044. PubMed
  211. Wang S, Li X, Yang Y, et al. Does coffee, tea and caffeine consumption reduce the risk of incident breast cancer? A systematic review and network meta-analysis. Public Health Nutr 2021;24(18):6377-6389. PubMed
  212. Alshabi AM, Alkahtani SA, Shaikh IA, Habeeb MS. Caffeine modulates pharmacokinetic and pharmacodynamic profiles of pioglitazone in diabetic rats: Impact on therapeutics. Saudi Med J 2021;42(2):151-160. PubMed
  213. Gleason JL, Sundaram R, Mitro SD, et al. Association of maternal caffeine consumption during pregnancy with child growth. JAMA Netw Open. 2022;5(10):e2239609. PubMed
  214. Seufferlein T, Ettrich TJ, Menzler S, et al. Green tea extract to prevent colorectal adenomas, results of a randomized, placebo-controlled clinical trial. Am J Gastroenterol 2022;117(6):884-894. PubMed
  215. Teramoto M, Yamagishi K, Muraki I, Tamakoshi A, Iso H. Coffee and green tea consumption and cardiovascular disease mortality among people with and without hypertension. J Am Heart Assoc 2023;12(2):e026477. PubMed
  216. Veerman GDM, van der Werff SC, Koolen SLW, et al. The influence of green tea extract on nintedanib's bioavailability in patients with pulmonary fibrosis. Biomed Pharmacother 2022;151:113101. PubMed
  217. Misaka S, Ono Y, Taudte RV, et al. Exposure of fexofenadine, but not pseudoephedrine, is markedly decreased by green tea extract in healthy volunteers. Clin Pharmacol Ther 2022;112(3):627-634. PubMed
  218. Zhao H, Zhu W, Zhao X, et al. Efficacy of epigallocatechin-3-gallate in preventing dermatitis in patients with breast cancer receiving postoperative radiotherapy: A double-blind, placebo-controlled, phase 2 randomized clinical trial. JAMA Dermatol 2022;15 PubMed
  219. Pochet S, Lechon AS, Lescrainier C, et al. Herb-anticancer drug interactions in real life based on VigiBase, the WHO global database. Sci Rep 2022;12(1):14178. PubMed

See these in context on the Green Tea monograph →

Echinacea 51 references
  1. Mullins RJ. Echinacea-associated anaphylaxis. Med J Aust 1998;168:170-1. PubMed
  2. Mullins RJ. Allergic reactions to Echinacea. J Allergy Clin Immunol 2000;104:S340-341 (Abstract 1003).
  3. Chavez ML, Chavez PI. Echinacea. Hosp Pharm 1998;33:180-8.
  4. Grimm W, Muller HH. A randomized controlled trial of the effect of fluid extract of Echinacea purpurea on the incidence and severity of colds and respiratory infections. Am J Med 1999;106:138-43. PubMed
  5. Taylor JA, Weber W, Standish L, et al. Efficacy and safety of echinacea in treating upper respiratory tract infections in children: a randomized controlled trial. JAMA 2003;290:2824-30.. PubMed
  6. Luettig B, Steinmuller C, Gifford GE, et al. Macrophage activation by the polysaccharide arabinogalactan isolated from plant cell cultures of Echinacea purpurea. J Natl Cancer Inst 1989;81:669-75. PubMed
  7. Stimpel M, Proksch A, Wagner H, et al. Macrophage activation and induction of macrophage cytotoxicity by purified polysaccharide fractions from the plant Echinacea purpurea. Infect Immun 1984;46:845-9. PubMed
  8. Budzinski JW, Foster BC, Vandenhoek S, Arnason JT. An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine 2000;7:273-82. PubMed
  9. Gallo M, Sarkar M, Au W, et al. Pregnancy outcome following gestational exposure to echinacea: A prospective controlled study. Arch Intern Med 2000;160:3141-3. PubMed
  10. Soon SL, Crawford RI. Recurrent erythema nodosum associated with echinacea herbal therapy. J Am Acad Dermatol 2001;44:298-9. PubMed
  11. Mullins RJ, Heddle R. Adverse reactions associated with echinacea: the Australian experience. Ann Allergy Asthma Immunol 2002;88:42-51. PubMed
  12. Logan JL, Ahmed J. Critical hypokalemic renal tubular acidosis due to Sjogren's syndrome: association with the purported immune stimulant echinacea. Clin Rheumatol 2003;22:158-9.
  13. Schulten B, Bulitta M, Ballering-Bruhl B, et al. Efficacy of Echinacea purpurea in patients with a common cold. A placebo-controlled, randomised, double-blind clinical trial. Arzneimittelforschung 2001;51:563-8.. PubMed
  14. Yale SH, Glurich I. Analysis of the inhibitory potential of Ginkgo biloba, Echinacea purpurea, and Serenoa repens on the metabolic activity of cytochrome P450 3A4, 2D6, and 2C9. J Altern Complement Med 2005;11:433-9.
  15. Yale SH, Liu K. Echinacea purpurea therapy for the treatment of the common cold: a randomized, double-blind, placebo-controlled clinical trial. Arch Intern Med 2004;164:1237-41. PubMed
  16. Gorski JC, Huang S, Zaheer NA, et al. The effect of echinacea (Echinacea purpurea root) on cytochrome P450 activity in vivo.Clin Pharmacol Ther 2003;73 (Abstract PDII-A-8):P94. PubMed
  17. Lee AN, Werth VP. Activation of autoimmunity following use of immunostimulatory herbal supplements. Arch Dermatol 2004;140:723-7. PubMed
  18. Goel V, Lovlin R, Barton R, et al. Efficacy of a standardized echinacea preparation (Echinilin) for the treatment of the common cold: a randomized, double-blind, placebo-controlled trial. J Clin Pharm Ther 2004;29:75-83.
  19. Barrett B. Medicinal properties of Echinacea: a critical review. Phytomedicine 2003;10:66-86. PubMed
  20. Huntley AL, Thompson Coon J, Ernst E. The safety of herbal medicinal products derived from Echinacea species: a systematic review. Drug Saf 2005;28:387-400. PubMed
  21. Turner RB, Bauer R, Woelkart K, et al. An evaluation of Echinacea angustifolia in experimental rhinovirus infections. N Engl J Med 2005;353:341-8.
  22. Gurley BJ, Gardner SF, Hubbard MA, et al. In vivo assessment of botanical supplementation on human cytochrome P450 phenotypes: Citrus aurantium, Echinacea purpurea, milk thistle, and saw palmetto. Clin Pharmacol Ther 2004;76:428-40. .
  23. Perri D, Dugoua JJ, Mills E, Koren G. Safety and efficacy of echinacea (Echinacea augustafolia, e. purpurea and e. pallida) during pregnancy and lactation. Can J Clin Pharmacol 2006;13:e262-7.
  24. Kocaman O, Hulagu S, Senturk O. Echinacea-induced severe acute hepatitis with features of cholestatic autoimmune hepatitis. Eur J Intern Med 2008;19:148. PubMed
  25. Barrett B, Brown R, Rakel D. et al. Echinacea for treating the common cold: a randomized trial. Ann Intern Med 2010;153:769-77. PubMed
  26. Press Release: Echinacea herbal products should not be used in children under 12 years old. Medicines and Healthcare Products Regulatory Agency (UK). August 20, 2012. Available at: www.mhra.gov.uk/NewsCentre/Pressreleases/CON180627. (Accessed 21 October
  27. Barrett B, Brown R, Rakel D, Rabago D, et al. Placebo effects and the common cold: a randomized controlled trial. Ann.Fam.Med 2011;9:312-22. PubMed
  28. Haller J, Freund, TF, Pelczer, KG, et al. The anxiolytic potential and psychotropic side effects of an echinacea preparation in laboratory animals and healthy volunteers. Phytother.Res. 2013;27:54-61.
  29. Grbic J, Wexler I, Celenti R, et al. A phase II trial of a transmucosal herbal patch for the treatment of gingivitis. J Am Dent.Assoc. 2011;142:1168-75. PubMed
  30. Schapowal A, Berger D, Klein P, et al. Echinacea/sage or chlorhexidine/lidocaine for treating acute sore throats: a randomized double-blind trial. Eur.J Med Res 9-1-2009;14:406-12. PubMed
  31. Bossaer JB and Odle BL. Probable etoposide interaction with Echinacea. J.Diet.Suppl 2012;9:90-5.
  32. Abdul MI, Jiang X, Williams KM, et al. Pharmacokinetic and pharmacodynamic interactions of echinacea and policosanol with warfarin in healthy subjects. Br J Clin.Pharmacol. 2010;69:508-15. PubMed
  33. Kemp, D. E. and Franco, K. N. Possible leukopenia associated with long-term use of echinacea. J Am Board Fam.Pract. 2002;15(5):417-419.
  34. Liatsos, G., Elefsiniotis, I., Todorova, R., and Moulakakis, A. Severe thrombotic thrombocytopenic purpura (TTP) induced or exacerbated by the immunostimulatory herb Echinacea. Am J Hematol. 2006;81(3):224.
  35. Penzak, S. R., Robertson, S. M., Hunt, J. D., Chairez, C., Malati, C. Y., Alfaro, R. M., Stevenson, J. M., and Kovacs, J. A. Echinacea purpurea significantly induces cytochrome P450 3A activity but does not alter lopinavir-ritonavir exposure in healthy s
  36. Maskatia, Z. K. and Baker, K. Hypereosinophilia associated with echinacea use. South.Med J 2010;103(11):1173-1174. PubMed
  37. Parnham MJ. Benefit-risk assessment of the squeezed sap of the purple coneflower (Echinacea purpurea) for long-term oral immunostimulation. Phytomed 1996;3:95-102. PubMed
  38. Schroder-Aasen T, Molden G, Nilsen OG. In vitro inhibition of CYP3A4 by the multiherbal commercial product Sambucus Force and its main constituents Echinacea purpurea and Sambucus nigra. Phytother Res 2012;26(11):1606-13.
  39. Moltó J, Valle M, Miranda C, et al. Herb-drug interaction between Echinacea purpurea and darunavir-ritonavir in HIV-infected patients. Antimicrob Agents Chemother 2011;55(1):326-30.
  40. Goey AK, Meijerman I, Rosing H, et al. The effect of Echinacea purpurea on the pharmacokinetics of docetaxel. Br J Clin Pharmacol 2013;76(3):467-74.
  41. Moltó J, Valle M, Miranda C, et al. Herb-drug interaction between Echinacea purpurea and etravirine in HIV-infected patients. Antimicrob Agents Chemother 2012;56(10):5328-31. PubMed
  42. Lawrenson JA, Walls T, Day AS. Echinacea-induced acute liver failure in a child. J Paediatr Child Health 2014;50(10):841.
  43. Hansen TS, Nilsen OG. In vitro CYP3A4 metabolism: inhibition by Echinacea purpurea and choice of substrate for the evaluation of herbal inhibition. Basic Clin Pharmacol Toxicol 2008;103:445-9.
  44. Gabranis I, Koufakis T1, Papakrivos I, Batala S. Echinacea-associated acute cholestatic hepatitis. J Postgrad Med. 2015;61(3):211-2. PubMed
  45. Jalloh MA, Gregory PJ, Hein D, et al. Dietary supplement interactions with antiretrovirals: a systematic review. Int J STD AIDS. 2017 Jan;28(1):4-15. PubMed
  46. Karsch-Völk M, Barrett B, Kiefer D, Bauer R, Ardjomand-Woelkart K, Linde K. Echinacea for preventing and treating the common cold. Cochrane Database Syst Rev.2014;(2):CD000530. doi: 10.1002/14651858.CD000530.pub3. PubMed
  47. Hoban CL, Byard RW, Musgrave IF. Analysis of spontaneous adverse drug reactions to echinacea, valerian, black cohosh and ginkgo in Australia from 2000 to 2015. J Integr Med. 2019;17(5):338-343. PubMed
  48. Ogal M, Johnston SL, Klein P, Schoop R. Echinacea reduces antibiotic usage in children through respiratory tract infection prevention: a randomized, blinded, controlled clinical trial. Eur J Med Res. 2021 Apr 8;26(1):33. PubMed
  49. Lopresti AL, Smith SJ. An investigation into the anxiety-relieving and mood-enhancing effects of Echinacea angustifolia (EP107 ™): A randomised, double-blind, placebo-controlled study. J Affect Disord 2021;293:229-237.
  50. Weishaupt R, Buchkov A, Kolev E, Klein P, Schoop R. Reduction of viral load in patients with acute sore throats: Results from an observational clinical trial with Echinacea / Salvia lozenges [published online ahead of print, 2023 Mar 8]. Complement Med Re
  51. Sumer J, Keckeis K, Scanferla G, et al. Novel Echinacea formulations for the treatment of acute respiratory tract infections in adults-A randomized blinded controlled trial. Front Med (Lausanne) 2023;10:948787. PubMed

See these in context on the Echinacea monograph →

Grapefruit 157 references
  1. Penzak SR, Gubbins PO, Gurley BJ, et al. Grapefruit juice decreases the systemic availability of itraconazole capsules in healthy volunteers. Ther Drug Monit 1999;21:304-9. PubMed
  2. Ioannides-Demos LL, Christophidis N, et al. Dosing implications of a clinical interaction between grapefruit juice and cyclosporine and metabolite concentrations in patients with autoimmune diseases. J Rheumatol 1997;24:49-54.
  3. Josefsson M, Zackrisson AL, Ahlner J. Effect of grapefruit juice on the pharmacokinetics of amlodipine in healthy volunteers. Eur J Clin Pharmacol 1996;51:189-93. PubMed
  4. Garg SK, Kumar N, Bhargava VK, Prabhakar SK. Effect of grapefruit juice on carbamazepine bioavailability in patients with epilepsy. Clin Pharmacol Ther 1998;64:286-8. PubMed
  5. Weber A, Jager R, Borner A, et al. Can grapefruit juice influence ethinylestradiol bioavailability? Contraception 1996;53:41-7.
  6. Schubert W, Cullberg G, Edgar B, Hedner T. Inhibition of 17 beta-estradiol metabolism by grapefruit juice in ovariectomized women. Maturitas 1994;20:155-63.
  7. Kantola T, Kivisto KT, Neuvonen PJ, et al. Grapefruit juice greatly increases serum concentrations of lovastatin and lovastatin acid. Clin Pharmacol Ther 1998 63:397-402. PubMed
  8. Bailey DG, Spence JD, Munoz C, Arnold JM. Interaction of citrus juices with felodipine and nifedipine. Lancet 1991;337:268-9. PubMed
  9. Bailey DG, Arnold JM, Strong HA, et al. Effect of grapefruit juice and naringin on nisoldipine pharmacokinetics. Clin Pharmacol Ther 1993;54:589-94. PubMed
  10. Rau SE, Bend JR, Arnold MO, et al. Grapefruit juice-terfenadine single-dose interaction: magnitude, mechanism, and relevance. Clin Pharmacol Ther 1997 61:401-9. PubMed
  11. Offman EM, Freeman DJ, Dresser GK, et al. Cisapride interaction with grapefruit juice and red wine. Clin Pharmacol Ther 2000;67:110 (abstract PI-83).
  12. Bailey DG, Dresser GK, Kreeft JH, et al. Grapefruit juice-felodipine interaction: Effect of segments and an extract from unprocessed fruit. Clin Pharmacol Ther 2000;67:107 (abstract PI-71).
  13. Soldner A, Christians U, Susanto M, et al. Grapefruit juice activates P-glycoprotein-mediated drug transport. Pharm Res 1999;16:478-85. PubMed
  14. Zaidenstein R, Avni B, Dishi V, et al. Effect of grapefruit juice on the pharmacokinetics of losartan in healthy volunteers. Clin Pharmacol Ther 1998;65:(abstract PI-60). DOI
  15. Dresser GK, Bailey DG, Carruthers SG. Grapefruit juice-felodipine interaction in healthy seniors. Clin Pharmacol Ther 1998;65:(abstract PIII-63).
  16. Varis T, Kivisto KT, Neuvonen PJ. Grapefruit juice can increase the plasma concentration of methylprednisolone. Eur J Clin Pharmacol 2000;56:489-93.
  17. Gross AS, Goh YD, Addison RS, et al. Influence of grapefruit juice on cisapride pharmacokinetics. Clin Pharmacol Ther 1999;65:395-401. PubMed
  18. Lilja JJ, Kivisto KT, Neuvonen PJ. Grapefruit juice increases serum concentrations of atorvastatin and has no effect on pravastatin. Clin Pharmacol Ther 1999;66:118-27. DOI
  19. Ozdemir M, Aktan Y, Boydag BS. Interaction between grapefruit juice and diazepam in humans. Eur J Drug Metab Pharmacokinet 1998;23:55-9. PubMed
  20. Zaidenstein R, Dishi V, Gips M, et al. The effect of grapefruit juice on the pharmacokinetics of orally administered verapamil. Eur J Clin Pharmacol 1998;54:337-40. PubMed
  21. Lilja JJ, Kivisto KT, Backman JT, et al. Grapefruit juice substantially increases plasma concentrations of buspirone. Clin Pharmacol Ther 1998;64:655-60. PubMed
  22. Kupferschmidt HH, Fattinger KE, Ha HR, et al. Grapefruit juice enhances the bioavailability of the HIV protease inhibitor saquinavir in man. Br J Clin Pharmacol 1998;45:355-9. DOI
  23. Lilja JJ, Kivisto KT, Neuvonen PJ. Grapefruit juice-simvastatin interaction: effect on serum concentrations of simvastatin, simvastatin acid, and HMG-CoA reductase inhibitors. Clin Pharmacol Ther 1998;64:477-83. PubMed
  24. Curhan GC, Willett WC, Speizer FE, Stamfer MJ. Beverage use and risk of kidney stones in women. Ann Intern Med 1998;128:534-40.
  25. Fuhr U. Drug Interactions with Grapefruit Juice. Drug Saf 1998;18:251-72. DOI
  26. Oesterheld J, Kallepalli BR. Grapefruit juice and clomipramine: shifting metabolitic ratios. J Clin Psychopharmacol 1997;17:62-3. PubMed
  27. van Agtmael MA, Gupta V, van der Wosten TH, et al. Grapefruit juice increases the bioavailability of artemether. Eur J Clin Pharmacol 1999;55:405-10. PubMed
  28. van Agtmael MA, Gupta V, van der Graaf CA, van Boxtel CJ. The effect of grapefruit juice on the time-dependent decline of artemether plasma levels in healthy subjects. Clin Pharmacol Ther 1999;66:408-14.
  29. Damkier P, Hansen LL, Brosen K. Effect of diclofenac, disulfiram, itraconazole, grapefruit juice and erythromycin on the pharmacokinetics of quinidine. Br J Clin Pharmacol 1999;48:829-38. PubMed
  30. Takanaga H, Ohnishi A, Murakami H, et al. Relationship between time after intake of grapefruit juice and the effect on pharmacokinetics and pharmacodynamics of nisoldipine in healthy subjects. Clin Pharmacol Ther 2000:67:201-14. PubMed
  31. Takanaga H, Ohnishi A, Matsuo H, et al. Pharmacokinetic analysis of felodipine-grapefruit juice interaction based on an irreversible enzyme inhibition model. Br J Clin Pharmacol 2000;49:49-58. PubMed
  32. Coreg monograph. In: Gillis MC, Ed. Compendium of Pharmaceuticals and Specialities (CPS). 34th ed. Ottawa, Ontario, CAN:Canadian Pharmacists Assn, 1999:395.
  33. Dresser GK, Bailey DG, Carruthers SG. Grapefruit juice-felodipine interaction in the elderly. Clin Pharmacol Ther 2000;68:28-34. PubMed
  34. Bailey DG, Dresser GK, Munoz C, et al. Reduction of fexofenadine bioavailability by fruit juices. Clin Pharmacol Ther 2001;69:P21.
  35. Lilja JJ, Kivisto KT, Backman JT, Neuvonen PJ. Effect of grapefruit juice dose on grapefruit juice-triazolam interaction: repeated consumption prolongs triazolam half-life. Eur J Clin Pharmacol 2000;56:411-5. PubMed
  36. Erlund I, Meririnne E, Alfthan G, Aro A. Plasma kinetics and urinary excretion of the flavanones naringenin and hesperetin in humans after ingestion of orange juice and grapefruit juice. J Nutr 2001;131:235-41. PubMed
  37. Ho PC, Ghose K, Saville D, Wanwimolruk S. Effect of grapefruit juice on pharmacokinetics and pharmacodynamics of verapamil enantiomers in healthy volunteers. Eur J Clin Pharmacol 2000;56:693-8. PubMed
  38. Uno T, Ohkubo T, Sugawara K, et al. Effects of grapefruit juice on the stereoselective disposition of nicardipine in humans: evidence for dominant presystemic elimination at the gut site. Eur J Clin Pharmacol 2000;56:643-9. PubMed
  39. Bailey DG, Dresser GK. Grapefruit juice-lovastatin interaction. Clin Pharmacol Ther 2000;67:690.
  40. Lilja JJ, Kivisto KT, Neuvonen PJ. Duration of effect of grapefruit juice on the pharmacokinetics of the CYP3A4 substrate simvastatin. Clin Pharmacol Ther 2000;68:384-90. PubMed
  41. Castro N, Jung H, Medina R, et al. Interaction between grapefruit juice and praziquantel in humans. Antimicrob Agents Chemother 2002;46:1614-6. PubMed
  42. Jetter A, Kinzig-Schippers M, Walchner-Bonjean M, et al. Effects of grapefruit juice on the pharmacokinetics of sildenafil. Clin Pharmacol Ther 2002;71:21-9. PubMed
  43. Ebert U, Oertel R, Kirch W. Influence of grapefruit juice on scopolamine pharmacokinetics and pharmacodynamics in healthy male and female subjects. Int J Clin Pharmacol Ther 2000;38:523-31. PubMed
  44. Fuhr U, Muller-Peltzer H, Kern R, et al. Effects of grapefruit juice and smoking on verapamil concentrations in steady state. Eur J Clin Pharmacol 2002;58:45-53. PubMed
  45. Kanazawa S, Ohkubo T, Sugawara K. The effects of grapefruit juice on the pharmacokinetics of erythromycin. Eur J Clin Pharmacol 2001;56:799-803. PubMed
  46. Reif S, Nicolson M, Bisset D, et al. Effect of grapefruit juice intake on etoposide bioavailability. Eur J Clin Pharmacol 2002;58:491-4.. PubMed
  47. Greenblatt DJ, von Moltke LL, Harmatz JS. Time course of recovery of cytochrome P450 3A function after single doses of grapefruit juice. Clin Pharmacol Ther 2003;74:121-29 . PubMed
  48. Gupta MC, Garg SK, Badyal D, et al. Effect of grapefruit juice on the pharmacokinetics of theophylline in healthy male volunteers. Methods Find Exp Clin Pharmacol 1999;21:679-82. PubMed
  49. Edwards DJ, Fitzsimmons ME, Schuetz EG, et al. 6',7'-Dihydroxybergamottin in grapefruit juice and Seville orange juice: effects on cyclosporine disposition, enterocyte CYP3A4, and P-glycoprotein. Clin Pharmacol Ther 1999;65:237-44. PubMed
  50. Rogers JD, Zhao J, Liu L, et al. Grapefruit juice has minimal effects on plasma concentrations of lovastatin-derived 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors. Clin Pharmacol Ther 1999;66:358-66. PubMed
  51. Veronese ML, Gillen LP, Burke JP, et al. Exposure-dependent inhibition of intestinal and hepatic CYP3A4 in vivo by grapefruit juice. J Clin Pharmacol 2003;43:831-9. . PubMed
  52. Bailey DG, Dresser GK, Bend JR. Bergamottin, lime juice, and red wine as inhibitors of cytochrome P450 3A4 activity: comparison with grapefruit juice. Clin Pharmacol Ther 2003;73:529-37 . PubMed
  53. Becquemont L, Verstuyft C, Kerb R, et al. Effect of grapefruit juice on digoxin pharmacokinetics in humans. Clin Pharmacol Ther 2001;70:311-6. DOI
  54. Dresser GK, Bailey DG, Leake BF, et al. Fruit juices inhibit organic anion transporting polypeptide-mediated drug uptake to decrease the oral availability of fexofenadine. Clin Pharmacol Ther 2002;71:11-20. PubMed
  55. Parker RB, Yates CR, Soberman JE, Laizure SC. Effects of grapefruit juice on intestinal P-glycoprotein: evaluation using digoxin in humans. Pharmacotherapy 2003;23:979-87. PubMed
  56. Di Marco MP, Edwards DJ, Wainer IW, Ducharme MP. The effect of grapefruit juice and seville orange juice on the pharmacokinetics of dextromethorphan: the role of gut CYP3A and P-glycoprotein. Life Sci 2002;71:1149-60. PubMed
  57. Gaudineau C, Beckerman R, Welbourn S, Auclair K. Inhibition of human P450 enzymes by multiple constituents of the Ginkgo biloba extract. Biochem Biophys Res Comm 2004;318:1072–8. PubMed
  58. Sullivan DM, Ford MA, Boyden TW. Grapefruit juice and the response to warfarin. Am J Health-Syst Pharm 1998;55:1581-3. PubMed
  59. Fukazawa I, Uchida N, Uchida E, Yasuhara H. Effects of grapefruit juice on the pharmacokinetics of atorvastatin and pravastatin in Japanese. Br J Clin Pharmacol 2003;57:448-55.
  60. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
  61. Zitron E, Scholz E, Owen RW, et al. QTc prolongation by grapefruit juice and its potential pharmacological basis: HERG channel blockade by flavonoids. Circulation 2005;835:835-8. PubMed
  62. Monroe KR, Murphy SP, Kolonel LN, Pike MC. Prospective study of grapefruit intake and risk of breast cancer in postmenopausal women: the Mutliethnic Cohort Study. Br J Cancer 2007;97:440-5.
  63. Farkas D, Oleson LE, Zhao Y, et al. Pomegranate juice does not impair clearance of oral or intravenous midazolam, a probe for cytochrome P450-3A activity: comparison with grapefruit juice. J Clin Pharmacol 2007;47:286-94. PubMed
  64. Potential drug interactions with grapefruit. Pharmacist's Letter / Prescriber's Letter 2007;23(2):230204.
  65. Dresser GK, Kim RB, Bailey DG. Effect of grapefruit juice volume on the reduction of fexofenadine bioavailability: possible role of organic anion transporting polypeptides. Clin Pharmacol Ther 2005;77:170-7. PubMed
  66. Greenblatt DJ. Analysis of drug interactions involving fruit beverages and organic anion-transporting polypeptides. J Clin Pharmacol 2009;49:1403-7. PubMed
  67. Bailey DG. Fruit juice inhibition of uptake transport: a new type of food-drug interaction. Br J Clin Pharmacol 2010;70:645-55. PubMed
  68. Product information for Cordarone. Wyeth Pharmaceuticals, Inc. Philadelphia, PA 19101. September 2006.
  69. Demarles D, Gillotin C, Bonaventure-Paci S, et al. Single-dose pharmacokinetics of amprenavir coadministered with grapefruit juice. Antimicrob Agents Chemother 2002;46:1589-90. PubMed
  70. Yasui N, Kondo T, Furukori H, et al. Effects of repeated ingestion of grapefruit juice on the single and multiple oral-dose pharmacokinetics and pharmacodynamics of alprazolam. Psychopharmacology (Berl) 2000;150:185-90. PubMed
  71. Hori H, Yoshimura R, Ueda N, et al. Grapefruit juice-fluvoxamine interaction -- is it risky or not? J Clin Psychopharmacol 2003;23:422-4. PubMed
  72. Benmebarek M, Devaud C, Gex-Fabry M, et al. Effects of grapefruit juice on the pharmacokinetics of the enantiomers of methadone. Clin Pharmacol Ther 2004;76:55-63.
  73. Yin OQ, Gallagher N, Li A, et al. Effect of grapefruit juice on the pharmacokinetics of nilotinib in healthy participants. J Clin Pharmacol 2010;50:188-94. PubMed
  74. Lilja JJ, Raaska K, Neuvonen PJ. Effects of grapefruit juice on the pharmacokinetics of acebutolol. Br J Clin Pharmacol 2005;60:659-63. PubMed
  75. Hollander, A. A., van Rooij, J., Lentjes, G. W., Arbouw, F., van Bree, J. B., Schoemaker, R. C., van Es, L. A., van der Woude, F. J., and Cohen, A. F. The effect of grapefruit juice on cyclosporine and prednisone metabolism in transplant patients. Clin Ph PubMed
  76. Sigusch, H., Hippius, M., Henschel, L., Kaufmann, K., and Hoffmann, A. Influence of grapefruit juice on the pharmacokinetics of a slow release nifedipine formulation. Pharmazie 1994;49(7):522-524.
  77. Andersen, V., Pedersen, N., Larsen, N. E., Sonne, J., and Larsen, S. Intestinal first pass metabolism of midazolam in liver cirrhosis --effect of grapefruit juice. Br J Clin Pharmacol 2002;54(2):120-124. PubMed
  78. Hukkinen, S. K., Varhe, A., Olkkola, K. T., and Neuvonen, P. J. Plasma concentrations of triazolam are increased by concomitant ingestion of grapefruit juice. Clin Pharmacol Ther 1995;58(2):127-131. PubMed
  79. Kupferschmidt, H. H., Ha, H. R., Ziegler, W. H., Meier, P. J., and Krahenbuhl, S. Interaction between grapefruit juice and midazolam in humans. Clin Pharmacol Ther 1995;58(1):20-28. PubMed
  80. Libersa, C. C., Brique, S. A., Motte, K. B., Caron, J. F., Guedon-Moreau, L. M., Humbert, L., Vincent, A., Devos, P., and Lhermitte, M. A. Dramatic inhibition of amiodarone metabolism induced by grapefruit juice. Br J Clin Pharmacol 2000;49(4):373-378. PubMed
  81. Min, D. I., Ku, Y. M., Geraets, D. R., and Lee, H. Effect of grapefruit juice on the pharmacokinetics and pharmacodynamics of quinidine in healthy volunteers. J Clin Pharmacol 1996;36(5):469-476. PubMed
  82. Lee, A. J., Chan, W. K., Harralson, A. F., Buffum, J., and Bui, B. C. The effects of grapefruit juice on sertraline metabolism: an in vitro and in vivo study. Clin Ther 1999;21(11):1890-1899. PubMed
  83. Kawakami, M., Suzuki, K., Ishizuka, T., Hidaka, T., Matsuki, Y., and Nakamura, H. Effect of grapefruit juice on pharmacokinetics of itraconazole in healthy subjects. Int J Clin Pharmacol Ther 1998;36(6):306-308.
  84. Benton, R. E., Honig, P. K., Zamani, K., Cantilena, L. R., and Woosley, R. L. Grapefruit juice alters terfenadine pharmacokinetics, resulting in prolongation of repolarization on the electrocardiogram. Clin Pharmacol Ther 1996;59(4):383-388. PubMed
  85. Clifford, C. P., Adams, D. A., Murray, S., Taylor, G. W., Wilkins, M. R., Boobis, A. R., and Davies, D. S. The cardiac effects of terfenadine after inhibition of its metabolism by grapefruit juice. Eur J Clin Pharmacol 1997;52(4):311-315. PubMed
  86. Ando, H., Tsuruoka, S., Yanagihara, H., Sugimoto, K., Miyata, M., Yamazoe, Y., Takamura, T., Kaneko, S., and Fujimura, A. Effects of grapefruit juice on the pharmacokinetics of pitavastatin and atorvastatin. Br J Clin Pharmacol 2005;60(5):494-497. DOI
  87. Lilja, J. J., Neuvonen, M., and Neuvonen, P. J. Effects of regular consumption of grapefruit juice on the pharmacokinetics of simvastatin. Br J Clin Pharmacol 2004;58(1):56-60. PubMed
  88. Charbit, B., Becquemont, L., Lepere, B., Peytavin, G., and Funck-Brentano, C. Pharmacokinetic and pharmacodynamic interaction between grapefruit juice and halofantrine. Clin Pharmacol Ther 2002;72(5):514-523. PubMed
  89. Cuong, B. T., Binh, V. Q., Dai, B., Duy, D. N., Lovell, C. M., Rieckmann, K. H., and Edstein, M. D. Does gender, food or grapefruit juice alter the pharmacokinetics of primaquine in healthy subjects? Br J Clin Pharmacol 2006;61(6):682-689. PubMed
  90. Culm-Merdek, K. E., von Moltke, L. L., Gan, L., Horan, K. A., Reynolds, R., Harmatz, J. S., Court MH, and Greenblatt, D. J. Effect of extended exposure to grapefruit juice on cytochrome P450 3A activity in humans: comparison with ritonavir. Clin Pharmacol
  91. Hugen, P. W., Burger, D. M., Koopmans, P. P., Stuart, J. W., Kroon, F. P., van Leusen, R., and Hekster, Y. A. Saquinavir soft-gel capsules (Fortovase) give lower exposure than expected, even after a high-fat breakfast. Pharm World Sci 2002;24(3):83-86.
  92. Sugimoto, K., Araki, N., Ohmori, M., Harada, K., Cui, Y., Tsuruoka, S., Kawaguchi, A., and Fujimura, A. Interaction between grapefruit juice and hypnotic drugs: comparison of triazolam and quazepam. Eur J Clin Pharmacol 2006;62(3):209-215. PubMed
  93. Lilja, J. J., Backman, J. T., Laitila, J., Luurila, H., and Neuvonen, P. J. Itraconazole increases but grapefruit juice greatly decreases plasma concentrations of celiprolol. Clin Pharmacol Ther 2003;73(3):192-198. PubMed
  94. Schwarz, U. I., Seemann, D., Oertel, R., Miehlke, S., Kuhlisch, E., Fromm, M. F., Kim, R. B., Bailey, D. G., and Kirch, W. Grapefruit juice ingestion significantly reduces talinolol bioavailability. Clin Pharmacol Ther 2005;77(4):291-301. PubMed
  95. Bailey, D. G., Arnold, J. M., Munoz, C., and Spence, J. D. Grapefruit juice--felodipine interaction: mechanism, predictability, and effect of naringin. Clin Pharmacol Ther 1993;53(6):637-642. PubMed
  96. Bailey, D. G., Arnold, J. M., Bend, J. R., Tran, L. T., and Spence, J. D. Grapefruit juice-felodipine interaction: reproducibility and characterization with the extended release drug formulation. Br J Clin Pharmacol 1995;40(2):135-140.
  97. Christensen, H., Asberg, A., Holmboe, A. B., and Berg, K. J. Coadministration of grapefruit juice increases systemic exposure of diltiazem in healthy volunteers. Eur J Clin Pharmacol 2002;58(8):515-520. PubMed
  98. Edgar, B., Bailey, D., Bergstrand, R., Johnsson, G., and Regardh, C. G. Acute effects of drinking grapefruit juice on the pharmacokinetics and dynamics of felodipine--and its potential clinical relevance. Eur J Clin Pharmacol 1992;42(3):313-317.
  99. Goosen, T. C., Cillie, D., Bailey, D. G., Yu, C., He, K., Hollenberg, P. F., Woster, P. M., Cohen, L., Williams, J. A., Rheeders, M., and Dijkstra, H. P. Bergamottin contribution to the grapefruit juice-felodipine interaction and disposition in humans. Cl PubMed
  100. Fuhr, U., Maier-Bruggemann, A., Blume, H., Muck, W., Unger, S., Kuhlmann, J., Huschka, C., Zaigler, M., Rietbrock, S., and Staib, A. H. Grapefruit juice increases oral nimodipine bioavailability. Int J Clin Pharmacol Ther 1998;36(3):126-132.
  101. Hashimoto, K., Shirafuji, T., Sekino, H., Matsuoka, O., Sekino, H., Onnagawa, O., Okamoto, T., Kudo, S., and Azuma, J. Interaction of citrus juices with pranidipine, a new 1,4-dihydropyridine calcium antagonist, in healthy subjects. Eur J Clin Pharmacol 1 PubMed
  102. Lundahl, J., Regardh, C. G., Edgar, B., and Johnsson, G. Effects of grapefruit juice ingestion--pharmacokinetics and haemodynamics of intravenously and orally administered felodipine in healthy men. Eur J Clin Pharmacol 1997;52(2):139-145. PubMed
  103. Lundahl, J., Regardh, C. G., Edgar, B., and Johnsson, G. Relationship between time of intake of grapefruit juice and its effect on pharmacokinetics and pharmacodynamics of felodipine in healthy subjects. Eur J Clin Pharmacol 1995;49(1-2):61-67. PubMed
  104. Rashid, T. J., Martin, U., Clarke, H., Waller, D. G., Renwick, A. G., and George, C. F. Factors affecting the absolute bioavailability of nifedipine. Br J Clin Pharmacol 1995;40(1):51-58. PubMed
  105. Soons, P. A., Vogels, B. A., Roosemalen, M. C., Schoemaker, H. C., Uchida, E., Edgar, B., Lundahl, J., Cohen, A. F., and Breimer, D. D. Grapefruit juice and cimetidine inhibit stereoselective metabolism of nitrendipine in humans. Clin Pharmacol Ther 1991; PubMed
  106. Rashid, J., McKinstry, C., Renwick, A. G., Dirnhuber, M., Waller, D. G., and George, C. F. Quercetin, an in vitro inhibitor of CYP3A, does not contribute to the interaction between nifedipine and grapefruit juice. Br J Clin Pharmacol 1993;36(5):460-463.
  107. Uno, T., Ohkubo, T., Motomura, S., and Sugawara, K. Effect of grapefruit juice on the disposition of manidipine enantiomers in healthy subjects. Br J Clin Pharmacol 2006;61(5):533-537. DOI
  108. Bistrup, C., Nielsen, F. T., Jeppesen, U. E., and Dieperink, H. Effect of grapefruit juice on Sandimmun Neoral absorption among stable renal allograft recipients. Nephrol Dial.Transplant. 2001;16(2):373-377. PubMed
  109. Ducharme, M. P., Warbasse, L. H., and Edwards, D. J. Disposition of intravenous and oral cyclosporine after administration with grapefruit juice. Clin Pharmacol Ther 1995;57(5):485-491. PubMed
  110. Ku, Y. M., Min, D. I., and Flanigan, M. Effect of grapefruit juice on the pharmacokinetics of microemulsion cyclosporine and its metabolite in healthy volunteers: does the formulation difference matter? J Clin Pharmacol 1998;38(10):959-965. PubMed
  111. Lee, M., Min, D. I., Ku, Y. M., and Flanigan, M. Effect of grapefruit juice on pharmacokinetics of microemulsion cyclosporine in African American subjects compared with Caucasian subjects: does ethnic difference matter? J Clin Pharmacol 2001;41(3):317-323 PubMed
  112. Schwarz, U. I., Johnston, P. E., Bailey, D. G., Kim, R. B., Mayo, G., and Milstone, A. Impact of citrus soft drinks relative to grapefruit juice on ciclosporin disposition. Br J Clin Pharmacol 2006;62(4):485-491. PubMed
  113. Yee, G. C., Stanley, D. L., Pessa, L. J., Dalla, Costa T., Beltz, S. E., Ruiz, J., and Lowenthal, D. T. Effect of grapefruit juice on blood cyclosporin concentration. Lancet 4-15-1995;345(8955):955-956. PubMed
  114. Paine, M. F., Widmer, W. W., Hart, H. L., Pusek, S. N., Beavers, K. L., Criss, A. B., Brown, S. S., Thomas, B. F., and Watkins, P. B. A furanocoumarin-free grapefruit juice establishes furanocoumarins as the mediators of the grapefruit juice-felodipine in
  115. Sigusch, H., Henschel, L., Kraul, H., Merkel, U., and Hoffmann, A. Lack of effect of grapefruit juice on diltiazem bioavailability in normal subjects. Pharmazie 1994;49(9):675-679.
  116. Fingerova, H., Oborna, I., Petrova, P., Budikova, M., and Jezdinsky, J. [Does grapefruit juice increase the bioavailability of orally administered sex steroids?]. Ceska.Gynekol. 2003;68(2):117-121.
  117. Glaeser, H., Bailey, D. G., Dresser, G. K., Gregor, J. C., Schwarz, U. I., McGrath, J. S., Jolicoeur, E., Lee, W., Leake, B. F., Tirona, R. G., and Kim, R. B. Intestinal drug transporter expression and the impact of grapefruit juice in humans. Clin Pharma PubMed
  118. Lilja, J. J., Laitinen, K., and Neuvonen, P. J. Effects of grapefruit juice on the absorption of levothyroxine. Br J Clin Pharmacol 2005;60(3):337-341. PubMed
  119. Kivisto, K. T., Lilja, J. J., Backman, J. T., and Neuvonen, P. J. Repeated consumption of grapefruit juice considerably increases plasma concentrations of cisapride. Clin Pharmacol Ther 1999;66(5):448-453. PubMed
  120. Desta, Z., Kivisto, K. T., Lilja, J. J., Backman, J. T., Soukhova, N., Neuvonen, P. J., and Flockhart, D. A. Stereoselective pharmacokinetics of cisapride in healthy volunteers and the effect of repeated administration of grapefruit juice. Br J Clin Pharm PubMed
  121. Odou, P., Ferrari, N., Barthelemy, C., Brique, S., Lhermitte, M., Vincent, A., Libersa, C., and Robert, H. Grapefruit juice-nifedipine interaction: possible involvement of several mechanisms. J Clin Pharm Ther 2005;30(2):153-158. PubMed
  122. Wason, S., DiGiacinto, J. L., and Davis, M. W. Effects of grapefruit and Seville orange juices on the pharmacokinetic properties of colchicine in healthy subjects. Clin Ther 2012;34(10):2161-2173. PubMed
  123. Bailey, D. G., Dresser, G. K., Kreeft, J. H., Munoz, C., Freeman, D. J., and Bend, J. R. Grapefruit-felodipine interaction: effect of unprocessed fruit and probable active ingredients. Clin Pharmacol Ther 2000;68(5):468-477. PubMed
  124. Kumar, A., Teuber, S. S., Naguwa, S., Prindiville, T., and Gershwin, M. E. Eosinophilic gastroenteritis and citrus-induced urticaria. Clin Rev Allergy Immunol 2006;30(1):61-70. PubMed
  125. Ferdman, R. M., Ong, P. Y., and Church, J. A. Pectin anaphylaxis and possible association with cashew allergy. Ann.Allergy Asthma Immunol. 2006;97(6):759-760. PubMed
  126. Guo, L. Q., Chen, Q. Y., Wang, X., Liu, Y. X., Chu, X. M., Cao, X. M., Li, J. H., and Yamazoe, Y. Different roles of pummelo furanocoumarin and cytochrome P450 3A5*3 polymorphism in the fate and action of felodipine. Curr Drug Metab 2007;8(6):623-630. PubMed
  127. Curhan, G. C., Willett, W. C., Rimm, E. B., Spiegelman, D., and Stampfer, M. J. Prospective study of beverage use and the risk of kidney stones. Am J Epidemiol. 2-1-1996;143(3):240-247. PubMed
  128. Holmberg MT, Tornio A, Joutsi-Korhonen L, Neuvonen M, Neuvonen PJ, Lassila R, Niemi M, Backman JT. Grapefruit juice markedly increases the plasma concentrations and antiplatelet effects of ticagrelor in healthy subjects. Br J Clin Pharmacol. 2013 Jun;75(6 PubMed
  129. Holmberg MT, Tornio A, Neuvonen M, Neuvonen PJ, Backman JT, Niemi M. Grapefruit juice inhibits the metabolic activation of clopidogrel. Clin Pharmacol Ther. 2014 Mar;95(3):307-13. PubMed
  130. Hu M, Mak VW, Yin OQ, Chu TT, Tomlinson B. Effects of grapefruit juice and SLCO1B1 388A>G polymorphism on the pharmacokinetics of pitavastatin. Drug Metab Pharmacokinet. 2013;28(2):104-8.
  131. Ieiri I, Doi Y, Maeda K, Sasaki T, Kimura M, Hirota T, Chiyoda T, Miyagawa M, Irie S, Iwasaki K, Sugiyama Y. Microdosing clinical study: pharmacokinetic, pharmacogenomic (SLCO2B1), and interaction (grapefruit juice) profiles of celiprolol following the or
  132. Misaka S, Miyazaki N, Yatabe MS, Ono T, Shikama Y, Fukushima T, Kimura J. Pharmacokinetic and pharmacodynamic interaction of nadolol with itraconazole, rifampicin and grapefruit juice in healthy volunteers. J Clin Pharmacol. 2013 Jul;53(7):738-45. PubMed
  133. Nieminen TH, Hagelberg NM, Saari TI, Neuvonen M, Neuvonen PJ, Laine K, Olkkola KT. Grapefruit juice enhances the exposure to oral oxycodone. Basic Clin Pharmacol Toxicol. 2010 Oct;107(4):782-8. PubMed
  134. Piccirillo G, Magrì D, Matera S, Magnanti M, Pasquazzi E, Schifano E, Velitti S, Mitra M, Marigliano V, Paroli M, Ghiselli A. Effects of pink grapefruit juice on QT variability in patients with dilated or hypertensive cardiomyopathy and in healthy subject
  135. Seidegård J, Randvall G, Nyberg L, Borgå O. Grapefruit juice interaction with oral budesonide: equal effect on immediate-release and delayed-release formulations. Pharmazie. 2009 Jul;64(7):461-5. DOI
  136. Shoaf SE, Mallikaarjun S, Bricmont P. Effect of grapefruit juice on the pharmacokinetics of tolvaptan, a non-peptide arginine vasopressin antagonist, in healthy subjects. Eur J Clin Pharmacol. 2012 Feb;68(2):207-11. PubMed
  137. Tanaka S, Uchida S, Miyakawa S, Inui N, Takeuchi K, Watanabe H, Namiki N. Comparison of inhibitory duration of grapefruit juice on organic anion-transporting polypeptide and cytochrome P450 3A4. Biol Pharm Bull. 2013;36(12):1936-41. PubMed
  138. Tapaninen T, Neuvonen PJ, Niemi M. Grapefruit juice greatly reduces the plasma concentrations of the OATP2B1 and CYP3A4 substrate aliskiren. Clin Pharmacol Ther. 2010 Sep;88(3):339-42. PubMed
  139. van Erp NP, Baker SD, Zandvliet AS, Ploeger BA, den Hollander M, Chen Z, den Hartigh J, König-Quartel JM, Guchelaar HJ, Gelderblom H. Marginal increase of sunitinib exposure by grapefruit juice. Cancer Chemother Pharmacol. 2011 Mar;67(3):695-703. PubMed
  140. Goldbart A, Press J, Sofer S, Kapelushnik J. Near fatal acute colchicine intoxication in a child. A case report. Eur J Pediatr. 2000;159(12):895-7. PubMed
  141. Dahan A, Amidon GL. Grapefruit juice and its constituents augment colchicine intestinal absorption: potential hazardous interaction and the role of p-glycoprotein. Pharm Res. 2009 Apr;26(4):883-92. PubMed
  142. Bailey DG. Predicting clinical relevance of grapefruit-drug interactions: a complicated process. J Clin Pharm Ther. 2017 Apr;42(2):125-27. PubMed
  143. Mouly S, Lloret-Linares C, Sellire PO, Sene D, Bergmann JF. Is the clinical relevance of drug-food and drug-herb interactions limited to grapefruit juice and Saint-John's Wort? Pharmacol Res. 2017 Apr;118:82-92. PubMed
  144. Tsuji H, Ohmura K, Nakashima R, et al. Efficacy and safety of grapefruit juice intake accompanying tacrolimus treatment in connective tissues disease patients. Intern Med. 2016;55(12):1547-52.
  145. Jia Y, Liu J, Xu J. Influence of grapefruit juice on pharmacokinetics of triptolide in rats grapefruit juice on the effects of triptolide. Xenobiotica. 2017 Apr 16:1-5. PubMed
  146. Kawaguchi-Suzuki M, Nasiri-Kenari N, Shuster J, et al. Effect of low-furanocoumarin hybrid grapefruit juice consumption on midazolam pharmacokinetics. J Clin Pharmacol. 2017 Mar;57(3):305-11. PubMed
  147. Chorin E, Hochstadt A, Granot Y, et al. Grapefruit juice prolongs the QT interval of healthy volunteers and patients with long QT syndrome. Heart Rhythm. 2019. pii: S1547-5271(19)30368-6. PubMed
  148. Ershad M, Cruz MD, Mostafa A, Mckeever R, Vearrier D, Greenberg MI. Opioid toxidrome following grapefruit juice consumption in the setting of methadone maintenance. J Addict Med 2019;[Epub ahead of print]. PubMed
  149. Shen X, Chen F, Wang F, Huang P, Luo W. The effect of grapefruit juice on the pharmacokinetics of tadalafil in rats. Biomed Res Int 2020;2020:1631735. PubMed
  150. Loretz C, Ho MD, Alam N, Mitchell W, Li AP. Application of cryopreserved human intestinal mucosa and cryopreserved human enterocytes in the evaluation of herb-drug interactions: evaluation of CYP3A inhibitory potential of grapefruit juice and commercial f
  151. Holmberg MT, Tornio A, Hyvärinen H, et al. Effect of grapefruit juice on the bioactivation of prasugrel. Br J Clin Pharmacol. 2015;80(1):139-45. PubMed
  152. Guideline on the investigation of drug interactions. CPMP/EWP/560/95/Rev. 1 Corr. 2. European Medicines Agency, 2015. Available at: https://www.ema.europa.eu/en/documents/scientific-guideline/guideline-investigation-drug-interactions-revision-1_en.pdf (As
  153. Cinderella MA, Morell B, Munjal S. Grapefruit Juice Cleanse Mimicking Quetiapine Overdose: Case Report and Review of Literature. J Clin Psychopharmacol 2021;41(6):690-692. PubMed
  154. Long Z, Ruan M, Wu W, Zeng Q, Li Q, Huang Z. The successful combination of grapefruit juice and venetoclax in an unfit acute myeloid leukemia patient with adverse risk: A case report. Front Oncol 2022;12:912696. PubMed
  155. Piscitelli J, Nikanjam M, Capparelli EV, et al. Fexofenadine Plasma Concentrations to Estimate Systemic Exposure in Healthy Adults Using a Limited Sampling Strategy with a Population Pharmacokinetic Approach. Ther Drug Monit 2023;45(4):539-545. PubMed
  156. Abu Dayyih W, Zakaraya Z, Hailat M, et al. The Validation and Determination of Empagliflozin Concentration in the Presence of Grapefruit Juice Using HPLC for Pharmacokinetic Applications. Molecules 2024;29(6):1236. PubMed
  157. Moffid MA, Mostafa EA, Mahmoud ST, Sayed RM. An eco-friendly ultra-performance liquid chromatography-mass spectrometry method for quantification of rivaroxaban and ticagrelor in rat plasma: grapefruit interactions. Bioanalysis 2023;15(22):1327-1341. PubMed

See these in context on the Grapefruit monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Supplement interaction checker › Check any supplement or product against your medications Drug–drug interactions › Check two or more of your medications against each other Browse medications A–Z › Every drug we've checked against herbs & supplements NDC & pricing lookup › Find a drug’s NDCs, packaging and costs Ask a pharmacist › Free, personal answer from our licensed team