Major interaction on record — check this product against your medications before combining. Based on 10 of 12 ingredients. Check your meds →
Dietary supplement

Ultimate Vitamin C Ingredients & Drug Interactions

by Purity Products

Ultimate Vitamin C label
See full label image
Capsule Category: Other Combinations
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Ultimate Vitamin C 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

Ultimate Vitamin C is a dietary supplement by Purity Products with 12 active ingredients. Its ingredients are commonly taken for bone health and osteoporosis, correcting vitamin d deficiency, immune system support.Based on those ingredients, 1,515 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Quercetin, Vitamin D, Cranberry juice concentrate. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Ultimate Vitamin C by Purity Products

Ask about any prescription or over-the-counter medication and we check it for interactions with Ultimate Vitamin C by Purity Products — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Ultimate Vitamin C by Purity Products

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 11, 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 12 of its 12 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

Ultimate Vitamin C contains 12 active ingredients: Vitamin D, Quercetin, Vitamin C, Cinnamon extract, Magnesium, Ferulic Acid, Cranberry juice concentrate, Elderberry extract, Apple extract, Pine bark extract, and Sweet Orange extract (Diosvein). The product also contains inactive ingredients including rice flour, vegetable cellulose, vegetable magnesium stearate, and titanium dioxide.

These ingredients work together as an antioxidant and immune-support blend. Vitamin C is the main ingredient by name; Magnesium supports muscle and nerve function; Vitamin D supports bone and immune health; and the plant extracts (Quercetin, Cranberry, Elderberry, Apple, Pine bark, and Sweet Orange) contribute polyphenols and other compounds typically marketed for antioxidant activity.

Does it work?

Moderate 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
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: Immune support and antioxidant defense.
  • We looked for evidence on: Allergic rhinitis (hay fever), Acute bronchitis, Asthma, Athletic performance, Atopic disease, Canker sores — and 4 related terms.
  • The strongest evidence on file: Vitamin D is rated "Possibly Effective" for Allergic rhinitis (hay fever) (Natural Medicines).
  • Also on file: Magnesium is rated "Possibly Effective" for Asthma.
  • Also on file: Maritime Pine is rated "Possibly Effective" for Asthma.

Evidence for effectiveness varies by ingredient and condition. Vitamin D is effective for rickets, osteomalacia (soft bones), renal bone disease, and hypoparathyroidism.

Magnesium is effective for constipation, indigestion, and pre-eclampsia in pregnancy. Vitamin C is effective for vitamin C deficiency and possibly effective for some forms of anemia.

Cranberry is possibly effective for urinary tract infection prevention. Pine bark extract is possibly effective for osteoarthritis and chronic venous insufficiency (leg swelling).

For most other uses listed — such as cognitive decline, allergies, asthma, and cold prevention — evidence is insufficient to rate the product's effectiveness in our data.

The evidence, ingredient by ingredient Vitamin D Quercetin Vitamin C Cassia Cinnamon Magnesium Cranberry Elderberry Apple

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 10 of the 10 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 10 of 10.
  • General safety write-ups exist for 10 of 10.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Vitamin D is generally well tolerated at recommended doses but can cause toxicity at very high doses, with symptoms of elevated calcium (hypercalcemia) and, rarely, bone loss or kidney problems. Vitamin C is safe at normal doses; at doses above 2 grams daily, it may cause stomach upset, kidney stones (especially in people at risk), and rare kidney damage.

Magnesium commonly causes loose stools and nausea, especially at higher doses. Quercetin at high doses and long-term use hasn't been well studied; avoid supplemental doses in pregnancy and while breastfeeding.

Cinnamon extract in supplement form may harm the liver over time due to its coumarin content; avoid medicinal doses in pregnancy. Cranberry concentrate is generally well tolerated but may cause stomach upset and diarrhea in large amounts.

Elderberry from ripe fruit is generally well tolerated; raw or unripe berries can be toxic and cause severe gastrointestinal symptoms. Apple extract is safe as food; concentrated extracts are not well studied.

Pine bark extract may cause dizziness, vertigo, headache, or, rarely, chest pain or heart problems in those with a history of heart disease.

Side effects, ingredient by ingredient Vitamin D Quercetin Vitamin C Cassia Cinnamon Magnesium Cranberry Elderberry Apple

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?
  • 10 of the 10 matched ingredients can interact with medications — Quercetin, Apple, Elderberry, Sweet Orange, Vitamin D, among others.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs; cancer treatments; diabetes medications; heart-rhythm medications; lithium; Parkinson's medications.
  • For scale: 1,516 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.

Check with your pharmacist before taking this product if you use levodopa/carbidopa (Sinemet) for Parkinson's — magnesium can cut its effectiveness significantly. Also double-check if you take blood thinners (especially warfarin or antiplatelet drugs), statins (atorvastatin, pravastatin), blood pressure or heart rhythm medications (verapamil, diltiazem, digoxin, thiazide diuretics, nifedipine, atenolol, aliskiren), antihistamines (fexofenadine), immunosuppressants, chemotherapy drugs, quinolone or other antibiotics, diabetes medications, or lithium.

If you take any of these, run them through the checker on this page.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with some supporting evidence for its stated purpose. Major medication interactions have been identified, and safety information is well characterized.

This product is a multivitamin-and-plant-extract blend with documented interactions across many medication classes — especially blood thinners, statins, blood pressure drugs, and Parkinson's medication. If you take any prescription drugs, check your exact medications with the tool below before starting.

Talk to your pharmacist or doctor about whether the individual ingredients and doses align with your health needs and medication regimen.

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

Assessment coverage: 10 of 12 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Mar 25, 2021.

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 Ultimate Vitamin C, straight from the product label.

Brand Purity Products
Net contents 60 Capsule(s)
Market status On market
Date entered into DSLD Mar 25, 2021
DSLD ID 244271
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses Nutrient, 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 Ultimate Vitamin C by Purity Products, 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
30
IngredientAmount% DV
Vitamin D50 mcg250%
Quercetin30 mg--
Vitamin C720 mg800%
Cinnamon extract20 mg--
Candelilla Wax20 mg--
Magnesium20 mg5%
Ferulic Acid10 mg--
Cranberry juice concentrate20 mg--
Elderberry extract20 mg--
Apple extract120 mg--
Pine bark extract20 mg--
Diosvein Sweet Orange extract40 mg--

Other ingredients: Rice Flour, Vegetable Cellulose, Vegetable Magnesium Stearate, Titanium Dioxide

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.
General Statements

Intelligent nutritional solutions

Premium grade supplements Since 1993

Formulation

Immune support formula

Multiple immune support co-factors Promotes antioxidant defense

Formula

Vitamin C Vitamin D Elderberry And more

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Suggested Use: As a dietary supplement, take 2 capsules daily. For daily use.

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

See for yourself

Ultimate Vitamin C by Purity Products label

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

Ultimate Vitamin C 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 Ultimate Vitamin C by Purity Products

These are the 12 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 Capsule(s) Dosage formCapsule Servings per container30 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.

Vitamin D

Interacts with
715 drugs
50 mcg per serving Form: Cholecalciferol

Vitamin D is a fat-soluble vitamin that helps your body absorb calcium and is important for healthy bones, muscles, and immune function. Many people,...

Vitamin D monograph & interactions

Quercetin

Interacts with
1,169 drugs
30 mg per serving

Quercetin is a plant flavonoid with antioxidant and anti-inflammatory properties found in many common foods and sold as a supplement. While early rese...

Quercetin monograph & interactions

Vitamin C

Interacts with
207 drugs
720 mg per serving Form: Ascorbic Acid, Ascorbyl Palmitate, Magnesium Ascorbate

Vitamin C (ascorbic acid) is an essential nutrient your body needs but cannot make, so you must get it from food or supplements. It's important for im...

Vitamin C monograph & interactions

Cinnamon extract

Interacts with
442 drugs
20 mg per serving

Cassia cinnamon is the common, inexpensive cinnamon used in cooking, and it is also taken as a supplement, most often for blood sugar support. The evi...

Cinnamon extract monograph & interactions

Candelilla Wax

20 mg per serving

Magnesium

Interacts with
295 drugs
20 mg per serving Form: Magnesium Ascorbate

Magnesium is an essential mineral your body needs for muscles, nerves, blood pressure, and many other functions, and supplements are useful for preven...

Magnesium monograph & interactions

Ferulic Acid

10 mg per serving

Cranberry juice concentrate

Interacts with
712 drugs
20 mg per serving

Cranberry is best known for helping to prevent repeated urinary tract infections (UTIs) in some people, and the evidence here is moderate but mixed. I...

Cranberry juice concentrate monograph & interactions

Elderberry extract

Interacts with
121 drugs
20 mg per serving

Elderberry is a popular herbal supplement, mainly taken to help with colds and flu. Some small studies suggest it may modestly shorten cold or flu sym...

Elderberry extract monograph & interactions

Apple extract

Interacts with
300 drugs
120 mg per serving

Apples are a nutritious whole food that provides fiber, vitamins, and antioxidant plant compounds, and eating them regularly fits well into a healthy...

Apple extract monograph & interactions

Pine bark extract

Interacts with
327 drugs
20 mg per serving

Maritime pine bark extract (often sold as Pycnogenol) is a plant-based antioxidant most studied for circulation, vein, and skin health. Some research...

Pine bark extract monograph & interactions

Diosvein Sweet Orange extract

Interacts with
246 drugs
40 mg per serving

Sweet orange is a common citrus fruit that is a good source of vitamin C, fiber, and antioxidants, and is enjoyed as a food worldwide. Its peel and es...

Diosvein Sweet Orange extract monograph & interactions

Other (inactive) ingredients: Rice Flour, Vegetable Cellulose, Vegetable Magnesium Stearate, Titanium Dioxide. These complete the product’s ingredient list but are not active constituents.

Interaction report

Ultimate Vitamin C by Purity Products Drug Interactions

Want to check YOUR meds against Ultimate Vitamin C?

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
1,515Drugs
54 Major 1,457 Moderate 4 Minor

Ingredients driving the most interactions

Quercetin 1,169
Vitamin D 715
Cranberry juice concentrate 712
Cinnamon extract 442
Pine bark extract 327

Individual Drug Interactions

The ingredients in Ultimate Vitamin C interact with 1,515 drugs. Click any drug to see the details.

10 of the 12 ingredients in Ultimate Vitamin C interact with drugs. Each result below shows which ingredient is responsible. Quercetin Vitamin D Cranberry juice concentrate Cinnamon extract Pine bark extract Apple extract Magnesium Diosvein Sweet Orange extract Vitamin C Elderberry extract

Each ingredient & the kinds of drugs it affects

For each ingredient in Ultimate Vitamin C 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.

Quercetin21 drug types · 1,169 drugs

Antidiabetes Drugs

Theoretically, concomitant use of quercetin and antidiabetes drugs might increase the risk of hypoglycemia.

Clinical research suggests that a combination of quercetin, myricetin, and chlorogenic acid reduce levels of fasting glucose in patients with type 2 diabetes, including those already taking antidiabetes agents. The effect of quercetin alone is unknown.

Likelihood Possible Evidence B
Antihypertensive Drugs

Theoretically, taking quercetin with antihypertensive drugs might increase the risk of hypotension.

Quercetin can modestly decrease blood pressure in people with mild hypertension. Theoretically, it might have additive blood pressure lowering effects when used with antihypertensive drugs.

Likelihood Possible Evidence B
Cyclosporine (Neoral, Sandimmune)

Theoretically, concomitant use might increase the levels and adverse effects of cyclosporine.

A small study in healthy volunteers shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of a single dose of cyclosporine, possibly due to inhibition of p-glycoprotein or cytochrome P450 3A4 (CYP3A4), which metabolizes cyclosporin.

Likelihood Possible Evidence B
Cytochrome P450 2C8 (Cyp2C8) Substrates

Theoretically, concomitant use might increase the levels and adverse effects of CYP2C8 substrates.

In vitro research shows that quercetin inhibits CYP2C8. Inhibition of paclitaxel (Taxol) metabolism via CYP2C8 has been reported in vitro. However, a small study in humans found no effect of quercetin on rosiglitazone (Avandia), which is also a CYP2C8 substrate.

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

Theoretically, concomitant use might increase the levels and adverse effects of CYP2C9 substrates.

A small clinical study in healthy volunteers shows that taking quercetin 500 mg twice daily for 10 days prior to taking diclofenac, a CYP2C9 substrate, increases diclofenac plasma levels by 75% and prolongs the half-life by 32.5%. Animal research also shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of losartan (Cozaar), a substrate of CYP2C9. Furthermore, laboratory research shows that quercetin inhibits CYP2C9.

Likelihood Possible Evidence B
Cytochrome P450 2D6 (Cyp2D6) Substrates

Theoretically, concomitant use might increase the levels and adverse effects of CYP2D6 substrates.

In vitro research show that quercetin inhibits CYP2D6. This effect has not been reported in humans.

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

Theoretically, concomitant use might alter the effects and adverse effects of CYP3A4 substrates.
A small clinical study in healthy volunteers shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of a single dose of cyclosporine (Neoral, Sandimmune), a substrate of CYP3A4. Animal research also shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of losartan (Cozaar) and quetiapine (Seroquel), substrates of CYP3A4. Other laboratory research also shows that quercetin inhibits CYP3A4. However, one clinical study shows that quercetin can increase the metabolism of midazolam, a substrate of CYP3A4, and decrease serum concentrations of midazolam by about 24% in some healthy individuals, suggesting possible induction of CYP3A4.

Likelihood Possible Evidence D
Diclofenac (Voltaren, Others)

Theoretically, concomitant use might increase the levels and adverse effects of diclofenac.

A small clinical study in healthy volunteers shows that taking quercetin 500 mg twice daily for 10 days prior to taking diclofenac increases diclofenac plasma levels by 75% and prolongs the half-life by 32.5%. This is thought to be due to inhibition of CYP2C9 by quercetin.

Likelihood Probable Evidence B
Losartan (Cozaar)

Theoretically, concomitant use might increase the effects and adverse effects of losartan and decrease the effects of its active metabolite.

Animal research shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of losartan (Cozaar) while decreasing plasma levels of losartan's active metabolite. This metabolite, which is around 10-fold more potent than losartan, is the result of cytochrome P450 (CYP) 2C9- and CYP3A4-mediated transformation of losartan. Additionally, in vitro research shows that quercetin may inhibit P-glycoprotein-mediated efflux of losartan from the intestines, resulting in increased absorption of losartan. These results suggest that concomitant use of quercetin and losartan might increase systemic exposure to losartan while also decreasing plasma concentrations of losartan's active and more potent metabolite.

Likelihood Possible Evidence D
Midazolam (Versed)

Theoretically, concomitant use might decrease the levels and effects of midazolam.

A small clinical study in healthy volunteers shows that quercetin can increase the metabolism of midazolam, with a decrease in AUC of about 24%.

Likelihood Possible Evidence B
Mitoxantrone

Theoretically, quercetin might increase the effects and adverse effects of mitoxantrone.
In vitro research shows that quercetin increases the intracellular accumulation and cytotoxicity of mitoxantrone, possibly through inhibition of breast cancer resistance protein (BCRP), of which mitoxantrone is a substrate. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Organic Anion Transporter 1 (Oat1) Substrates

Theoretically, concomitant use might increase the effects and adverse effects of OAT1 substrates.

In vitro research shows that quercetin is a strong non-competitive inhibitor of OAT1, with half-maximal inhibitory concentration (IC50) values less than 10 mcM. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Organic Anion Transporter 3 (Oat3) Substrates

Theoretically, concomitant use might increase the effects and adverse effects of OAT3 substrates.

In vitro research shows that quercetin is a strong non-competitive inhibitor of OAT3, with half-maximal inhibitory concentration (IC50) values as low as 0.75 mcM. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Organic Anion-Transporting Polypeptide Substrates (Oatp)

Theoretically, concomitant use might increase the effects and adverse effects of OATP substrates.

In vitro evidence shows that quercetin can inhibit organic anion-transporting peptide (OATP) 1B1-mediated uptake of estrone-3-sulfate and pravastatin. Furthermore, clinical research in healthy males shows that intake of quercetin along with pravastatin increases the AUC of pravastatin by 24%, prolongs its half-life by 14%, and decreases its apparent clearance by 18%, suggesting that quercetin modestly inhibits the uptake of pravastatin in hepatic cells.

Likelihood Possible Evidence B
P-Glycoprotein Substrates

Theoretically, concomitant use might alter the effects and adverse effects of P-glycoprotein substrates.

There is preliminary evidence that quercetin inhibits the gastrointestinal P-glycoprotein efflux pump, which might increase the bioavailability and serum levels of drugs transported by the pump. A small study in healthy volunteers reported that pretreatment with quercetin increased bioavailability and plasma levels after a single dose of cyclosporine (Neoral, Sandimmune). Also, two small studies have shown that quercetin might decrease the absorption of talinolol, a substrate transported by the gastrointestinal P-glycoprotein efflux pump. However, in another small study, several days of quercetin treatment did not significantly affect the pharmacokinetics of saquinavir (Invirase). The reason for these discrepancies is not entirely clear. Until more is known, use quercetin cautiously in combination with P-glycoprotein substrates.

Likelihood Possible Evidence B
Pravastatin (Pravachol)

Theoretically, concomitant use might increase the effects and adverse effects of pravastatin.
In vitro evidence shows that quercetin can inhibit OATP 1B1-mediated uptake of pravastatin. Also, preliminary clinical research in healthy males shows that intake of quercetin along with pravastatin increases the maximum concentration of pravastatin by 24%, prolongs its half-life by 14%, and decreases its apparent clearance by 18%, suggesting that quercetin modestly inhibits the uptake of pravastatin in hepatic cells.

Likelihood Possible Evidence B
Prazosin (Minipress)

Theoretically, quercetin might increase the effects and adverse effects of prazosin.
In vitro research shows that quercetin inhibits the transcellular efflux of prazosin, possibly through inhibition of breast cancer resistance protein (BCRP), of which prazosin is a substrate. BCRP is an ATP-binding cassette efflux transporter in the intestines, kidneys, and liver. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Quetiapine (Seroquel)

Theoretically, concomitant use might increase the effects and adverse effects of quetiapine.
Animal research shows that pretreatment with quercetin can increase plasma levels of quetiapine and prolong its clearance, possibly due to inhibition of cytochrome P450 3A4 (CYP3A4) by quercetin. Additionally, the brain-to-plasma ratio of quetiapine concentrations increased, possibly due to inhibition of P-glycoprotein at the blood-brain barrier. This interaction has not been reported in humans.

Likelihood Possible Evidence D
Quinolone Antibiotics

Theoretically, concomitant use might inhibit the effects of quinolone antibiotics.
In vitro, quercetin binds to the DNA gyrase site on bacteria, which may interfere with the activity of quinolone antibiotics.

Likelihood Possible Evidence B
Sulfasalazine (Azulfidine)

Theoretically, quercetin might increase the effects and adverse effects of sulfasalazine.
Animal research shows that quercetin increases the maximum serum concentration (Cmax) and area under the curve (AUC) of sulfasalazine, possibly through inhibition of breast cancer resistance protein (BCRP), of which sulfasalazine is a substrate. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Theoretically, quercetin may increase the risk of bleeding if used with warfarin.
Animal and in vitro studies show that quercetin might increase serum levels of warfarin. Quercetin and warfarin have the same human serum albumin (HSA) binding site, and in vitro research shows that quercetin has stronger affinity for the HSA binding site and can theoretically displace warfarin, causing higher serum levels of warfarin. Animal research shows that taking quercetin for 2 weeks before initiating warfarin increases the maximum serum level of warfarin by 30%, the half-life by 10%, and the overall exposure by 63% when compared with control. Concomitant administration of quercetin and warfarin, without quercetin pre-treatment, also increased these measures, but to a lesser degree. Researchers theorize that inhibition of CYP3A4 by quercetin may explain these effects. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Quercetin full monograph & interactions

Vitamin D8 drug types · 715 drugs

Aluminum

Vitamin D might increase aluminum absorption and toxicity, but this has only been reported in people with renal failure.
The protein that transports calcium across the intestinal wall can also bind and transport aluminum. This protein is stimulated by vitamin D, which may therefore increase aluminum absorption. This mechanism may contribute to increased aluminum levels and toxicity in people with renal failure, when they take vitamin D and aluminum-containing phosphate binders chronically.

Likelihood Probable Evidence B
Atorvastatin (Lipitor)

Vitamin D might reduce absorption of atorvastatin.
A small, low-quality clinical study shows that taking vitamin D reduces levels of atorvastatin and its active metabolites by up to 55%. However, while atorvastatin levels decreased, total cholesterol, low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol levels did not substantially change. Atorvastatin is metabolized in the gut by CYP3A4 enzymes, and researchers theorized that vitamin D might induce CYP3A4, causing reduced levels of atorvastatin. However, this proposed mechanism was not specifically studied.

Likelihood Probable Evidence B
Calcipotriene (Dovonex)

Taking calcipotriene with vitamin D increases the risk for hypercalcemia.
Calcipotriene is a vitamin D analog used topically for psoriasis. It can be absorbed in sufficient amounts to cause systemic effects, including hypercalcemia. Theoretically, combining calcipotriene with vitamin D supplements might increase the risk of hypercalcemia.

Likelihood Probable Evidence D
Digoxin (Lanoxin)

Theoretically, hypercalcemia induced by high-dose vitamin D can increase the risk of arrhythmia from digoxin.
High doses of vitamin D can cause hypercalcemia. Hypercalcemia increases the risk of fatal cardiac arrhythmias with digoxin. Avoid vitamin D doses above the tolerable upper intake level (4000 IU daily for adults) and monitor serum calcium levels in people taking vitamin D and digoxin concurrently.

Likelihood Possible Evidence D
Diltiazem (Cardizem, Others)

Theoretically, hypercalcemia induced by high-dose vitamin D can reduce the therapeutic effects of diltiazem for arrhythmia.
High doses of vitamin D can cause hypercalcemia. Hypercalcemia can reduce the effectiveness of verapamil in atrial fibrillation. Theoretically this could also occur with diltiazem. Avoid vitamin D doses above the tolerable upper intake level (4000 IU daily for adults) and monitor serum calcium levels in people taking vitamin D and diltiazem concurrently.

Likelihood Probable Evidence B
Thiazide Diuretics

Theoretically, taking thiazide diuretics and high-dose vitamin D can increase the risk of hypercalcemia.
Thiazide diuretics decrease urinary calcium excretion, which could lead to hypercalcemia if vitamin D supplements are taken concurrently. This has been reported in people being treated with vitamin D for hypoparathyroidism, and also in elderly people with normal parathyroid function who were taking a thiazide, vitamin D, and calcium-containing antacids daily.

Likelihood Probable Evidence D
Verapamil (Calan, Others)

Hypercalcemia induced by high-dose vitamin D can reduce the therapeutic effects of verapamil for arrhythmia.
Hypercalcemia due to high doses of vitamin D can reduce the effectiveness of verapamil in atrial fibrillation. Avoid vitamin D doses above the tolerable upper intake level (4000 IU daily for adults) and monitor serum calcium levels in people taking vitamin D and verapamil concurrently.

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

Vitamin D might induce CYP3A4 enzymes and reduce the bioavailability of CYP3A4 substrates.
There is some concern that vitamin D might induce CYP3A4. In vitro research suggests that vitamin D induces CYP3A4 transcription. Additionally, observational research has found that increased UV light exposure and serum vitamin D levels are associated with decreased serum levels of CYP3A4 substrates such as tacrolimus and sirolimus, while no association between UV light exposure or vitamin D levels and levels of mycophenolic acid, a non-CYP3A4 substrate, was found. A small, low-quality clinical study shows that taking vitamin D reduces levels of the CYP3A4 substrate atorvastatin and its active metabolites by up to 55%; however, the clinical effects of atorvastatin were not reduced. While researchers theorized that vitamin D might induce CYP3A4, this proposed mechanism was not specifically studied.

Likelihood Possible Evidence D
Vitamin D full monograph & interactions

Cranberry juice concentrate6 drug types · 712 drugs

Atorvastatin (Lipitor)

Theoretically, cranberry might increase levels and adverse effects of atorvastatin.
In one case report, a patient taking atorvastatin experienced upper back pain, rhabdomyolysis, and abnormal liver function after drinking cranberry juice 16 ounces daily for 2 weeks. Theoretically, this may have been caused by inhibition of cytochrome P450 3A4 (CYP3A4) enzymes by cranberry juice, as atorvastatin is a CYP3A4 substrate. Creatinine kinase and liver enzymes normalized within 2 weeks of stopping cranberry juice. Patients taking atorvastatin should avoid large quantities of cranberry juice.

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

Theoretically, cranberry might increase the levels and adverse effects of CYP3A4 substrates.
A case of upper back pain, rhabdomyolysis, and abnormal liver function has been reported for a patient taking atorvastatin, a CYP3A4 substrate, in combination with cranberry juice 16 ounces daily for 2 weeks. Creatinine kinase and liver enzymes normalized within 2 weeks of stopping cranberry juice. Also, animal research suggests that cranberry juice, administered intraduodenally 30 minutes prior to nifedipine, a CYP3A4 substrate, inhibits nifedipine metabolism and increases the area under the concentration-time curve by 1.6-fold compared to control.

Likelihood Possible Evidence D
Nifedipine (Procardia)

Theoretically, cranberry might increase the levels and adverse effects of nifedipine.
Animal research suggests that cranberry juice, administered intraduodenally 30 minutes prior to nifedipine treatment, inhibits nifedipine metabolism and increases the area under the concentration-time curve by 1.6-fold compared to control. This interaction has not been reported in humans.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Theoretically, cranberry might increase the levels and adverse effects of warfarin. However, research is conflicting.
There is contradictory evidence about the effect of cranberry juice on warfarin. Case reports have linked cranberry juice consumption to increases in the international normalized ratio (INR) in patients taking warfarin, resulting in severe spontaneous bleeding and excessive postoperative bleeding. Daily consumption of cranberry sauce for one week has also been linked to an increase in INR in one case report. In a small study in healthy young males, taking a high dose of 3 grams of cranberry juice concentrate capsules, equivalent to 57 grams of fruit daily, for 2 weeks produced a 30% increase in the area under the INR-time curve after a single 25-mg dose of warfarin. However, 3 very small clinical studies in patients stabilized on warfarin reported that cranberry juice 250 mL once or twice daily for 7 days (27% cranberry juice or pure cranberry juice) or 240 mL once daily for 14 days does not significantly increase INR or affect plasma warfarin levels. The reasons for these discrepant findings are unclear. It is possible that the form and dose of cranberry may play a role, as cranberry extracts and juices contain different constituents. Additionally, an in vitro study evaluating 5 different cranberry juices found varying effects, with only a cranberry concentrate, and not diluted cranberry juices, inhibiting CYP2C9. However, this concentrate did not inhibit CYP2C9 activity in humans.

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

Theoretically, cranberry might increase the levels and adverse effects of CYP2C9 substrates. However, research is conflicting.
There is contradictory evidence about the effect of cranberry on CYP2C9 enzymes. In vitro evidence suggests that flavonoids in cranberry inhibit CYP2C9 enzymes. However, clinical research shows that cranberry juice does not significantly affect the levels, metabolism, or elimination of the CYP2C9 substrates flurbiprofen or diclofenac. Also, in patients stabilized on warfarin, drinking cranberry juice 250 mL daily for 7 days does not significantly increase the anticoagulant activity of warfarin, a CYP2C9 substrate. Additional pharmacokinetic research shows that cranberry juice does not increase peak plasma concentrations or area under the concentration-time curve of warfarin.

Likelihood Unlikely Evidence B
Diclofenac (Voltaren, Others)

Theoretically, cranberry might modestly increase the levels and adverse effects of diclofenac.
In vitro evidence suggests that cranberry juice inhibits diclofenac metabolism by human liver microsomes. However, drinking cranberry juice does not seem to affect diclofenac metabolism in humans.

Likelihood Unlikely Evidence B
Cranberry juice concentrate full monograph & interactions

Cinnamon extract2 drug types · 442 drugs

Antidiabetes Drugs

Theoretically, cassia cinnamon may have additive effects with antidiabetes drugs.
Cassia cinnamon may lower blood glucose levels, and have additive effects in patients treated with antidiabetic agents. Dose adjustments to diabetes medications might be necessary.

Likelihood Possible Evidence B
Hepatotoxic Drugs

Theoretically, large doses of cassia cinnamon might cause additive effects when used with hepatotoxic drugs.
There is some concern that ingesting large amounts of cassia cinnamon for an extended duration might cause hepatotoxicity in some people. Cassia cinnamon contains coumarin, which can cause hepatotoxicity in animal models. In humans, very high doses of coumarin from 50-7000 mg/day can result in hepatotoxicity that resolves when coumarin use is discontinued. Lower amounts might also cause liver problems in sensitive people, such as those with liver disease or those taking potentially hepatotoxic agents.

Likelihood Possible Evidence D
Cinnamon extract full monograph & interactions

Pine bark extract3 drug types · 327 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, maritime pine bark extract might increase the risk of bleeding when used with antiplatelet or anticoagulant drugs.
Clinical research suggests that maritime pine bark extract inhibits platelet aggregation. However, the clinical significance of this effect is unclear.

Likelihood Possible Evidence D
Antidiabetes Drugs

Theoretically, maritime pine bark extract might increase the risk of hypoglycemia when used with antidiabetes drugs.
One clinical study shows that maritime pine bark extract decreases blood sugar in patients with diabetes being treated with antidiabetes agents. Monitor blood glucose levels closely. Dose adjustments might be necessary.

Likelihood Possible Evidence B
Immunosuppressants

Theoretically, maritime pine bark extract might decrease the effectiveness of immunosuppressant therapy.
In vitro and animal research suggests that maritime pine bark extract has immunostimulant activity. This effect has not been reported in humans.

Likelihood Possible Evidence D
Pine bark extract full monograph & interactions

Apple extract7 drug types · 300 drugs

Organic Anion-Transporting Polypeptide Substrates (Oatp)

Concomitant consumption of apple juice can significantly decrease oral absorption and blood levels of OATP substrates.
Research shows that consuming apple juice inhibits OATP, which reduces bioavailability of oral drugs that are substrates of OATP. Fexofenadine, atenolol, and aliskiren are substrates of OATP. Clinical research shows that coadministration of apple juice decreases bioavailability of fexofenadine by up to 78%, aliskiren by 63%, and atenolol by up to 82%. These effects appear to increase with larger quantities of apple juice. It is thought that apple juice might affect OATP for only a short time. Therefore, separating drug administration and consumption of apple juice by at least 4 hours might avoid this interaction.

Likelihood Likely Evidence B
Aliskiren (Tekturna, Rasilez)

Concomitant consumption of apple juice can significantly decrease oral absorption and blood levels of aliskiren.
Pharmacokinetic research shows that coadministration of apple juice 200 mL along with aliskiren 150 mg decreases the bioavailability of aliskiren by 63%. Apple juice seems to inhibit organic anion transporting polypeptide (OATP), which is involved in drug uptake in the gut, liver, and kidney. It is thought that apple juice might affect OATP for only a short time. Therefore, separating drug administration and consumption of apple juice by at least 4 hours might avoid this interaction.

Likelihood Probable Evidence B
Antidiabetes Drugs

Theoretically, consuming apple juice with antidiabetes drugs might interfere with blood glucose control.
Clinical research suggests that consuming apples or drinking apple juice can raise blood glucose levels, with the effects of drinking apple juice being more significant than consuming apples.

Likelihood Possible Evidence D
Antihypertensive Drugs

Consuming apple juice with antihypertensive drugs might interfere with blood pressure control.
Some clinical evidence suggests that consuming apple and cherry juice can increase blood pressure in elderly patients.

Likelihood Probable Evidence B
Atenolol (Tenormin)

Concomitant consumption of apple juice can significantly decrease oral absorption and blood levels of atenolol.
Pharmacokinetic research shows that coadministration of apple juice 600-1200 mL decreases levels of atenolol by 58% to 82% in a dose-dependent manner. Apple juice seems to inhibit organic anion transporting polypeptide (OATP), which is involved in drug uptake in the gut, liver, and kidney. It is thought that apple juice might affect OATP for only a short time. Therefore, separating drug administration and consumption of apple juice by at least 4 hours might avoid this interaction.

Likelihood Probable Evidence B
Fexofenadine (Allegra)

Concomitant consumption of apple juice can significantly decrease oral absorption and blood levels of fexofenadine.
Pharmacokinetic research shows that coadministration of apple juice 400-1200 mL along with fexofenadine 60-120 mg decreases bioavailability of fexofenadine by up to 78%. Coadministration with smaller quantities of apple juice (150 mL or less) does not appear to affect the bioavailability of fexofenadine. Apple juice seems to inhibit organic anion transporting polypeptide (OATP), which is involved in drug uptake in the gut, liver, and kidney. It is thought that apple juice might affect OATP for only a short time. Therefore, separating drug administration and consumption of apple juice by at least 4 hours might avoid this interaction.

Likelihood Likely Evidence B
Lithium

There is some concern that concomitant consumption of apple juice might decrease oral absorption and blood levels of lithium.
In one case report, a patient had an undetectable serum lithium level when lithium citrate was administered with apple juice. When lithium was administered with an alternative beverage, the lithium level became detectable and the patient demonstrated clinical improvement.

Likelihood Possible Evidence D
Apple extract full monograph & interactions

Magnesium15 drug types · 295 drugs

Levodopa/Carbidopa (Sinemet)

Magnesium can reduce the bioavailability of levodopa/carbidopa.
Clinical research in healthy volunteers shows that taking magnesium oxide 1000 mg with levodopa 100 mg/carbidopa 10 mg reduces the area under the curve (AUC) of levodopa by 35% and of carbidopa by 81%. In vitro and animal research shows that magnesium produces an alkaline environment in the digestive tract, which might lead to degradation and reduced bioavailability of levodopa/carbidopa.

Likelihood Probable Evidence B
Aminoglycoside Antibiotics

Concomitant use of aminoglycoside antibiotics and magnesium can increase the risk for neuromuscular weakness.
Both aminoglycosides and magnesium reduce presynaptic acetylcholine release, which can lead to neuromuscular blockade and possible paralysis. This is most likely to occur with high doses of magnesium given intravenously.

Likelihood Possible Evidence D
Antacids

Use of acid reducers may reduce the laxative effect of magnesium oxide.
A retrospective analysis shows that, in the presence of H2 receptor antagonists (H2RAs) or proton pump inhibitors (PPIs), a higher dose of magnesium oxide is needed for a laxative effect. This may also occur with antacids. Under acidic conditions, magnesium oxide is converted to magnesium chloride and then to magnesium bicarbonate, which has an osmotic laxative effect. By reducing acidity, antacids may reduce the conversion of magnesium oxide to the active bicarbonate salt.

Likelihood Possible Evidence D
Bictegravir/Emtricitabine/Tenofovir Alafenamide (Biktarvy)

Magnesium might decrease levels of bictegravir/emtricitabine/tenofovir alafenamide by reducing its absorption.
Advise patients that bictegravir/emtricitabine/tenofovir alafenamide should be taken at least 2 hours before or 6 hours after magnesium containing products.

Likelihood Probable Evidence D
Bisphosphonates

Magnesium can decrease absorption of bisphosphonates.
Cations, including magnesium, can decrease bisphosphonate absorption. Advise patients to separate doses of magnesium and these drugs by at least 2 hours.

Likelihood Probable Evidence B
Calcium Channel Blockers

Magnesium can have additive effects with calcium channel blockers, although evidence is conflicting.
Magnesium inhibits calcium entry into smooth muscle cells and may therefore have additive effects with calcium channel blockers. Severe hypotension and neuromuscular blockades may occur when nifedipine is used with intravenous magnesium, although some contradictory evidence suggests that concurrent use of magnesium with nifedipine does not increase the risk of neuromuscular weakness. High doses of magnesium could theoretically have additive effects with other calcium channel blockers.

Likelihood Possible Evidence D
Digoxin

Magnesium salts may reduce absorption of digoxin.
Clinical evidence suggests that treatment with oral magnesium hydroxide or magnesium trisilicate reduces absorption of digoxin from the intestines. This may reduce the blood levels of digoxin and decrease its therapeutic effects.

Likelihood Possible Evidence B
Potassium-Sparing Diuretics

Potassium-sparing diuretics decrease excretion of magnesium, possibly increasing magnesium levels.
Potassium-sparing diuretics also have magnesium-sparing properties, which can counteract the magnesium losses associated with loop and thiazide diuretics. Theoretically, increased magnesium levels could result from concomitant use of potassium-sparing diuretics and magnesium supplements.

Likelihood Probable Evidence D
Quinolone Antibiotics

Magnesium decreases absorption of quinolones.
Magnesium can form insoluble complexes with quinolones and decrease their absorption. Advise patients to take these drugs at least 2 hours before, or 4 to 6 hours after, magnesium supplements.

Likelihood Probable Evidence D
Skeletal Muscle Relaxants

Parenteral magnesium alters the pharmacokinetics of skeletal muscle relaxants, increasing their effects and accelerating the onset of effect.
Parenteral magnesium shortens the time to onset of skeletal muscle relaxants by about 1 minute and prolongs the duration of action by about 2 minutes. Magnesium potentiates the effects of skeletal muscle relaxants by decreasing calcium-mediated release of acetylcholine from presynaptic nerve terminals, reducing postsynaptic sensitivity to acetylcholine, and having a direct effect on the membrane potential of myocytes. Magnesium also has vasodilatory actions and increases cardiac output, allowing a greater amount of muscle relaxant to reach the motor end plate. A clinical study found that low-dose rocuronium (0.45 mg/kg), when given after administration of magnesium 30 mg/kg over 10 minutes, has an accelerated onset of effect, which matches the onset of effect seen with a full-dose rocuronium regimen (0.6 mg/kg). In another clinical study, onset times for rocuronium doses of 0.3, 0.6, and 1.2 mg/kg were 86, 76, and 50 seconds, respectively, when given alone, but were reduced to 66, 44, and 38 seconds, respectively, when the doses were given after a 15-minute infusion of magnesium sulfate 60 mg/kg. Giving intraoperative intravenous magnesium sulfate, 50 mg/kg loading dose followed by 15 mg/kg/hour, reduces the onset time of rocuronium, enhances its clinical effects, reduces the dose of intraoperative opiates, and prolongs the spontaneous recovery time. It does not affect the activity of subsequently administered neostigmine.

Likelihood Probable Evidence A
Sulfonylureas

Magnesium increases the systemic absorption of sulfonylureas, increasing their effects and side effects.
Clinical research shows that administration of magnesium hydroxide with glyburide increases glyburide absorption, increases maximal insulin response by 35-fold, and increases the risk of hypoglycemia, when compared with glyburide alone. A similar interaction occurs between magnesium hydroxide and glipizide. The mechanism of this effect appears to be related to the elevation of gastrointestinal pH by magnesium-based antacids, increasing solubility and enhancing absorption of sulfonylureas.

Likelihood Probable Evidence B
Tetracycline Antibiotics

Magnesium decreases absorption of tetracyclines.
Magnesium can form insoluble complexes with tetracyclines in the gut and decrease their absorption and antibacterial activity. Advise patients to take these drugs 1 hour before or 2 hours after magnesium supplements.

Likelihood Probable Evidence D
Anticoagulant/Antiplatelet Drugs

Theoretically, magnesium may have antiplatelet effects, but the evidence is conflicting.
In vitro evidence shows that magnesium sulfate inhibits platelet aggregation, even at low concentrations. Some preliminary clinical evidence shows that infusion of magnesium sulfate increases bleeding time by 48% and reduces platelet activity. However, other clinical research shows that magnesium does not affect platelet aggregation, although inhibition of platelet-dependent thrombosis can occur.

Likelihood Unlikely Evidence B
Gabapentin (Neurontin)

Gabapentin absorption can be decreased by magnesium.
Clinical research shows that giving magnesium oxide orally along with gabapentin decreases the maximum plasma concentration of gabapentin by 33%, time to maximum concentration by 36%, and area under the curve by 43%. Advise patients to take gabapentin at least 2 hours before, or 4 to 6 hours after, magnesium supplements.

Likelihood Unlikely Evidence B
Sevelamer (Renagel, Renvela)

Sevelamer may increase serum magnesium levels.
In patients on hemodialysis, sevelamer use was associated with a 0.28 mg/dL increase in serum magnesium. The mechanism of this interaction remains unclear.

Likelihood Possible Evidence B
Magnesium full monograph & interactions

Diosvein Sweet Orange extract7 drug types · 246 drugs

Celiprolol (Celicard)

Consuming sweet orange with celiprolol can decrease oral absorption of celiprolol.
A pharmacokinetic study in healthy volunteers shows that celiprolol levels, after a single dose of 100 mg, are decreased by up to 90% in people who drink sweet orange juice 200 mL three times daily. It's not known if lower consumption of sweet orange juice will have the same effect. Theoretically, this occurs due to short-term inhibition of organic anion transporting polypeptide (OATP). Recommend separating drug administration and consumption of sweet orange by at least 4 hours.

Likelihood Likely Evidence B
Ivermectin (Stromectol, Others)

Consuming sweet orange juice with ivermectin can decrease the oral absorption of ivermectin.
A pharmacokinetic study in healthy volunteers shows that taking ivermectin orally with sweet orange juice 750 mL over 4 hours reduces the bioavailability of ivermectin. This effect does not seem to be related to effects on P-glycoprotein. The effect on ivermectin is more pronounced in males compared to females.

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

Consuming sweet orange juice can decrease oral absorption of OATP substrates. Separate administration by at least 4 hours.
Clinical research shows that consuming sweet orange juice inhibits OATP, which reduces bioavailability of oral drugs that are substrates of OATP. For example, sweet orange juice decreases bioavailability of fexofenadine, a substrate of OATP, by about 72% and of celiprolol, another OATP substrate, by up to 90%. Since sweet orange juice seems to affect OATP for a short time, recommend separating drug administration and consumption of sweet orange juice by at least 4 hours.

Likelihood Likely Evidence B
Pravastatin (Pravachol)

Consuming sweet orange juice with pravastatin can increase the absorption of pravastatin.
A small pharmacokinetic study in healthy volunteers shows that consuming sweet orange juice 800 mL over 3 hours, including before, during, and after taking pravastatin 10 mg, increases pravastatin levels by about 149%, without affecting pravastatin elimination. Theoretically this effect might be due to modulation of organic anion transporting polypeptides (OATPs) by sweet orange juice. Sweet orange juice does not seem to affect simvastatin levels, but it is not known if sweet orange affects any of the other statins.

Likelihood Likely Evidence B
Fexofenadine (Allegra)

Consuming sweet orange juice with fexofenadine can decrease oral absorption of fexofenadine.
Clinical research shows that coadministration of sweet orange juice 1200 mL decreases bioavailability of fexofenadine by about 72%. In an animal model, sweet orange juice decreased bioavailability of fexofenadine by 31%. Fexofenadine manufacturer data indicates that concomitant administration of sweet orange juice and fexofenadine results in larger wheal and flare sizes in research models. This suggests that sweet orange reduces the clinical response to fexofenadine. Theoretically, this occurs due to short-term inhibition of organic anion transporting polypeptide (OATP). Recommend separating drug administration and consumption of sweet orange by at least 4 hours.

Likelihood Likely Evidence B
P-Glycoprotein Substrates

Sweet orange juice seems to modulate P-glycoprotein (P-gp), which might affect the blood levels of P-gp substrates.
Animal and in vitro research suggest that orange juice extract inhibits drug efflux by P-gp, increasing absorption and levels of P-gp substrates. In contrast, pharmacokinetic research in humans shows that drinking large amounts of sweet orange juice decreases absorption and levels of the P-gp substrate celiprolol. This suggests that orange juice actually induces drug efflux by P-gp or affects drug levels by another mechanism such as inhibiting the gut drug transporter called organic anion transporting polypeptide (OATP). Until more is known, sweet orange juice should be used cautiously in people taking P-gp substrates.

Likelihood Possible Evidence B
Quinolone Antibiotics

Calcium-fortified sweet orange juice might reduce quinolone absorption.
Calcium binds to quinolones in the gut. Theoretically, the calcium in certain fortified orange juices can also bind to quinolone antibiotics and reduce their absorption and levels.

Likelihood Possible Evidence D
Diosvein Sweet Orange extract full monograph & interactions

Vitamin C13 drug types · 207 drugs

Alkylating Agents

Theoretically, antioxidant effects of vitamin C might reduce the effectiveness of alkylating agents.
The use of antioxidants like vitamin C during chemotherapy is controversial. There is concern that antioxidants could reduce the activity of chemotherapy drugs that generate free radicals, such as cyclophosphamide, chlorambucil, carmustine, busulfan, and thiotepa. In contrast, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that could interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effect, if any, antioxidants such as vitamin C have on chemotherapy.

Likelihood Possible Evidence D
Aluminum

Vitamin C can increase the amount of aluminum absorbed from aluminum compounds.
Research in animals and humans shows that vitamin C increases aluminum absorption, theoretically by chelating aluminum and keeping it in solution where it is available for absorption. In people with normal renal function, urinary excretion of aluminum will likely increase, making aluminum retention and toxicity unlikely. Patients with renal failure who take aluminum-containing compounds such as phosphate binders should avoid vitamin C supplements in doses above the recommended dietary allowances.

Likelihood Probable Evidence B
Antitumor Antibiotics

Theoretically, the antioxidant effects of vitamin C might reduce the effectiveness of antitumor antibiotics.
The use of antioxidants like vitamin C during chemotherapy is controversial. There is concern that antioxidants could reduce the activity of chemotherapy drugs which generate free radicals, such as doxorubicin. In contrast, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that could interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effects, if any, antioxidants such as vitamin C have on chemotherapy.

Likelihood Possible Evidence D
Estrogens

Vitamin C might increase blood levels of estrogens.
Increases in plasma estrogen levels of up to 55% occur under some circumstances when vitamin C is taken concurrently with oral contraceptives or hormone replacement therapy, including topical products. It is suggested that vitamin C prevents oxidation of estrogen in the tissues, regenerates oxidized estrogen, and reduces sulfate conjugation of estrogen in the gut wall. When tissue levels of vitamin C are high, these processes are already maximized and supplemental vitamin C does not have any effect on estrogen levels. Increases in plasma estrogen levels may occur when patients who are deficient in vitamin C take supplements. Monitor these patients for estrogen-related side effects.

Likelihood Probable Evidence B
Fluphenazine (Prolixin)

Theoretically, vitamin C might decrease levels of fluphenazine.
In one patient there was a clinically significant decrease in fluphenazine levels when vitamin C (500 mg twice daily) was started. The mechanism is not known, and there is no further data to confirm this interaction.

Likelihood Possible Evidence D
Indinavir (Crixivan)

Vitamin C can modestly reduce indinavir levels.
One pharmacokinetic study shows that taking vitamin C 1 gram orally once daily along with indinavir 800 mg orally three times daily reduces the area under the concentration-time curve of indinavir by 14%. The mechanism of this interaction is unknown, but it is unlikely to be clinically significant in most patients. The effect of higher doses of vitamin C on indinavir levels is unknown.

Likelihood Probable Evidence B
Levothyroxine (Synthroid, Others)

Vitamin C can increase levothyroxine absorption.
Two clinical studies in adults with poorly controlled hypothyroidism show that swallowing levothyroxine with a glass of water containing vitamin C 500-1000 mg in solution reduces thyroid stimulating hormone (TSH) levels and increases thyroxine (T4) levels when compared with taking levothyroxine alone. This suggests that vitamin C increases the oral absorption of levothyroxine, possibly due to a reduction in pH.

Likelihood Probable Evidence B
Warfarin (Coumadin)

High-dose vitamin C might reduce the levels and effectiveness of warfarin.
Vitamin C in high doses may cause diarrhea and possibly reduce warfarin absorption. There are reports of two people who took up to 16 grams daily of vitamin C and had a reduction in prothrombin time. Lower doses of 5-10 grams daily can also reduce warfarin absorption. In many cases, this does not seem to be clinically significant. However, a case of warfarin resistance has been reported for a patient who took vitamin C 500 mg twice daily. Cessation of vitamin C supplementation resulted in a rapid increase in international normalized ratio (INR). Tell patients taking warfarin to avoid taking vitamin C in excessively high doses (greater than 10 grams daily). Lower doses may be safe, but the anticoagulation activity of warfarin should be monitored. Patients who are stabilized on warfarin while taking vitamin C should avoid adjusting vitamin C dosage to prevent the possibility of warfarin resistance.

Likelihood Possible Evidence D
Acetaminophen (Tylenol, Others)

High-dose vitamin C might slightly prolong the clearance of acetaminophen.
A small pharmacokinetic study in healthy volunteers shows that taking high-dose vitamin C (3 grams) 1.5 hours after taking acetaminophen 1 gram slightly increases the apparent half-life of acetaminophen from around 2.3 hours to 3.1 hours. Ascorbic acid competitively inhibits sulfate conjugation of acetaminophen. However, to compensate, elimination of acetaminophen glucuronide and unconjugated acetaminophen increases. This effect is not likely to be clinically significant.

Likelihood Probable Evidence B
Aspirin

Acidification of the urine by vitamin C might increase aspirin levels.
It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels. However, short-term use of up to 6 grams daily of vitamin C does not seem to affect urinary pH or salicylate excretion, suggesting this interaction is not clinically significant.

Likelihood Possible Evidence B
Choline Magnesium Trisalicylate (Trilisate)

Acidification of the urine by vitamin C might increase choline magnesium trisalicylate levels.
It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels. However, short-term use of up to 6 grams daily of vitamin C does not seem to affect urinary pH or salicylate excretion, suggesting this interaction probably is not clinically significant.

Likelihood Possible Evidence B
Niacin

Vitamin C might decrease the beneficial effects of niacin on high-density lipoprotein (HDL) cholesterol levels.
A combination of niacin and simvastatin (Zocor) effectively raises HDL cholesterol levels in patients with coronary disease and low HDL levels. Clinical research shows that taking a combination of antioxidants (vitamin C, vitamin E, beta-carotene, and selenium) along with niacin and simvastatin (Zocor) attenuates this rise in HDL, specifically the HDL-2 and apolipoprotein A1 fractions, by more than 50% in patients with coronary disease. It is not known whether this adverse effect is due to a single antioxidant such as vitamin C, or to the combination. It also is not known whether it will occur in other patient populations.

Likelihood Possible Evidence A
Salsalate (Disalcid)

Acidification of the urine by vitamin C might increase salsalate levels.
It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels. However, short-term use of up to 6 grams/day vitamin C does not seem to affect urinary pH or salicylate excretion, suggesting this interaction probably is not clinically significant.

Likelihood Possible Evidence B
Vitamin C full monograph & interactions

Elderberry extract2 drug types · 121 drugs

Immunosuppressants

Theoretically, elderberry might interfere with immunosuppressant therapy due to its immunostimulant activity.
Elderberry has immunostimulant activity, increasing the production of cytokines, including interleukin and tumor necrosis factor.

Likelihood Possible Evidence B
Pazopanib (Votrient)

Theoretically, elderberry might interact with pazopanib, potentially increasing the risk of adverse effects.
In one case, a 65-year-old patient taking pazopanib for 4 weeks for soft-tissue sarcoma developed severe nausea, loose stools, and elevated alanine transaminase and aspartate transaminase levels and was diagnosed with grade 3 liver injury. The patient reported taking elderberry supplements for 2 years, dose unspecified, and was also taking a multivitamin and a calcium supplement. The patient's symptoms and liver enzyme levels improved upon discontinuation of pazopanib and all supplements. Pazopanib treatment was re-initiated, at a lower dose, with no further evidence of liver injury. It was unclear in this case report if the elderberry supplements were derived from the berry, the flower, or the combination.

Likelihood Possible Evidence D
Elderberry extract full monograph & interactions
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Pharmacist Counseling Corner

Ultimate Vitamin C by Purity Products: Common Questions

Does Ultimate Vitamin C by Purity Products interact with any medications?
Yes. Based on its ingredients, Ultimate Vitamin C has a known interaction with 1,515 medications, including 54 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Ultimate Vitamin C contains 12 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.
Can I take this if I'm pregnant?
It depends on the ingredient. Vitamin D and magnesium are often used in pregnancy under medical supervision. Vitamin C in normal amounts is likely fine. Quercetin and elderberry lack enough safety data — avoid supplemental doses. Cinnamon extract in high-dose supplement form isn't recommended; food amounts are fine. Apple extract as food is safe; concentrated form isn't well studied. Talk to your doctor or pharmacist about which ingredients are right for you.
Is there any ingredient in this that has no drug interactions?
Candelilla wax and ferulic acid — we have no interaction data on file for these two. That doesn't mean they have no interactions; it means we haven't checked them. If you take medications, the most important check is on the other ten active ingredients, which do have documented interactions.
What's magnesium doing in a vitamin C product?
Magnesium supports muscle and nerve function and is often paired with vitamin C in antioxidant blends. However, magnesium can significantly reduce how much levodopa (Sinemet) your body absorbs, so if you take that drug, this product isn't a good fit.
Why is there so much apple and orange extract if this is a vitamin C product?
Apple and sweet orange extracts are included for their polyphenol antioxidants and their vitamin C content. However, both can interfere with how your body absorbs and processes several medications — statins, blood pressure drugs, and antihistamines among them — so they're not innocent additions if you take those drugs.
Does vitamin C in this product really prevent colds?
Our data shows vitamin C is possibly effective for exercise-induced respiratory infections. For preventing common colds in the general population, evidence is insufficient to rate. The product does not claim to prevent or treat disease, so talk to your doctor if you're looking for cold prevention.
What are the most common side effects?
Vitamin C at high doses can cause stomach cramps, nausea, and diarrhea. Magnesium commonly causes loose stools and nausea. Cranberry and apple extracts may cause stomach upset and diarrhea. Elderberry extracts prepared from ripe fruit are generally well tolerated; dizziness and headache have been reported with some standardized pine bark extracts. Most adverse effects occur at higher doses.

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

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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.

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Go deeper

The Full Monographs Behind Ultimate Vitamin C’s Ingredients

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

Herb & supplement monograph

Vitamin D

Interacts with 715 drugs

Vitamin D is a fat-soluble vitamin that helps your body absorb calcium and is important for healthy bones, muscles, and immune function. Many people, especially those with low sun exposure,...

Read the full Vitamin D monograph → Herb & supplement monograph

Quercetin

Interacts with 1,169 drugs

Quercetin is a plant flavonoid with antioxidant and anti-inflammatory properties found in many common foods and sold as a supplement. While early research is interesting for allergies, blood...

Read the full Quercetin monograph → Herb & supplement monograph

Vitamin C

Interacts with 207 drugs

Vitamin C (ascorbic acid) is an essential nutrient your body needs but cannot make, so you must get it from food or supplements. It's important for immune function, collagen, and acts as an...

Read the full Vitamin C monograph → Herb & supplement monograph

Cassia Cinnamon

Interacts with 442 drugs

Cassia cinnamon is the common, inexpensive cinnamon used in cooking, and it is also taken as a supplement, most often for blood sugar support. The evidence for its health benefits is mixed a...

Read the full Cassia Cinnamon monograph → Herb & supplement monograph

Magnesium

Interacts with 295 drugs

Magnesium is an essential mineral your body needs for muscles, nerves, blood pressure, and many other functions, and supplements are useful for preventing or correcting deficiency. Some othe...

Read the full Magnesium monograph → Herb & supplement monograph

Cranberry

Interacts with 712 drugs

Cranberry is best known for helping to prevent repeated urinary tract infections (UTIs) in some people, and the evidence here is moderate but mixed. It is not a reliable treatment for an act...

Read the full Cranberry monograph → Herb & supplement monograph

Elderberry

Interacts with 121 drugs

Elderberry is a popular herbal supplement, mainly taken to help with colds and flu. Some small studies suggest it may modestly shorten cold or flu symptoms, but the evidence is limited and n...

Read the full Elderberry monograph → Herb & supplement monograph

Apple

Interacts with 300 drugs

Apples are a nutritious whole food that provides fiber, vitamins, and antioxidant plant compounds, and eating them regularly fits well into a healthy diet. While research suggests apples may...

Read the full Apple monograph → Herb & supplement monograph

Maritime Pine

Interacts with 327 drugs

Maritime pine bark extract (often sold as Pycnogenol) is a plant-based antioxidant most studied for circulation, vein, and skin health. Some research is promising, but many studies are small...

Read the full Maritime Pine monograph → Herb & supplement monograph

Sweet Orange

Interacts with 246 drugs

Sweet orange is a common citrus fruit that is a good source of vitamin C, fiber, and antioxidants, and is enjoyed as a food worldwide. Its peel and essential oil are used in aromatherapy and...

Read the full Sweet Orange monograph →
Sources

Sources & How We Checked

Ultimate Vitamin C'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 291 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.

Vitamin D 26 references
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Tatro DS, ed. Drug Interactions Facts. Facts and Comparisons Inc., St. Louis, MO. 1999.
  3. Koutkia P, Chen TC, Holick MF. Vitamin D intoxication associated with an over-the-counter supplement. N Engl J Med 2001;345:66-7. PubMed
  4. Bar-Or D, Yoel G. Calcium and calciferol antagonize effect of verapamil in atrial fibrillation. Br Med J 1981;282:1585-6.
  5. Demontis R, Leflon A, Fournier A, et al. 1 alpha(OH) vitamin D3 increases plasma aluminum in hemodialyzed patients taking AI(OH)3. Clin Nephrol 1986;26:146-9.
  6. Crowe M, Wollner L, Griffiths RA. Hypercalcemia following vitamin D and thiazide therapy in the elderly. Practitioner 1984;228:312-3.
  7. Parfitt AM. Thiazide-induced hypercalcemia in vitamin D-treated hypoparathyroidism. Ann Intern Med 1972;77:557-63. PubMed
  8. Thiazide diuretics and the risk of osteoporosis. Pharmacist's Letter/Prescriber's Letter 2003;19(11):191105.
  9. Moon J. The role of vitamin D in toxic metal absorption. J Am Coll Nutr 1994;13:559-64.
  10. Demontis R, Reissi D, Noel C, et al. Indirect clinical evidence that 1alphaOH vitamin D<SUB>3</SUB> increases the intestinal absorption of aluminum. Clin Nephrol 1989;31:123-7.
  11. Adler AJ, Berlyne GM. Duodenal aluminum absorption in the rat: effect of vitamin D. Am J Physiol 1985;249:G209-13. PubMed
  12. Schwartz JB. Effects of vitamin D supplementation in atorvastatin-treated patients: A new drug interaction with an unexpected consequence. Clin Pharmacol Ther 2009;85:198-203. PubMed
  13. Dietary reference intakes for calcium and vitamin D. Institute of Medicine, November 30, 2010. Available at: http://www.iom.edu/~/media/Files/Report%20Files/2010/Dietary-Reference-Intakes-for-Calcium-and-Vitamin-D/Vitamin%20D%20and%20Calcium%202010%20Repo
  14. Cox KA, Dunn MA. Aluminum toxicity alters the regulation of calbindin-D28k protein and mRNA expression in chick intestine. J Nutr 2001;131:2007-13. PubMed
  15. Escribano, J., Balaguer, A., Pagone, F., Feliu, A., and Roque, I. Figuls. Pharmacological interventions for preventing complications in idiopathic hypercalciuria. Cochrane.Database.Syst.Rev. 2009;(1):CD004754. PubMed
  16. Carlton, S., Clopton, D., and Cappuzzo, K. A. Vitamin D deficiency: appropriate replenishment therapies and the effects of vitamin D toxicity. Consult Pharm 2010;25(3):171-177. PubMed
  17. Wang, H., Xia, N., Yang, Y., and Peng, D. Q. Influence of vitamin D supplementation on plasma lipid profiles: a meta-analysis of randomized controlled trials. Lipids Health Dis. 2012;11:42. PubMed
  18. Turner AN, Carr Reese P, Fields KS, Anderson J, Ervin M, Davis JA, Fichorova RN, Roberts MW, Klebanoff MA, Jackson RD. A blinded, randomized controlled trial of high-dose vitamin D supplementation to reduce recurrence of bacterial vaginosis. Am J Obstet G PubMed
  19. Weiner M, Epstein FH. Signs and symptoms of electrolyte disorders. Yale J Biol Med. 1970;43(2):76-109.
  20. Lappe J, Watson P, Travers-Gustafson D, Recker R, Garland C, Gorham E, Baggerly K, McDonnell SL. Effect of Vitamin D and Calcium Supplementation on Cancer Incidence in Older Women: A Randomized Clinical Trial. JAMA. 2017 Mar 28;317(12):1234-1243. PubMed
  21. Roth DE, Leung M, Mesfin E, Qamar H, Watterworth J, Papp E. Vitamin D supplementation during pregnancy: state of the evidence from a systematic review of randomised trials. BMJ. 2017;359:j5237. PubMed
  22. Murai IH, Fernandes AL, Sales LP, et al. Effect of a single high dose of vitamin D3 on hospital length of stay in patients with moderate to severe COVID-19: A randomized clinical trial. JAMA. 2021.
  23. Wang Z, Schuetz EG, Xu Y, Thummel KE. Interplay between vitamin D and the drug metabolizing enzyme CYP3A4. J Steroid Biochem Mol Biol 2013;136:54-8. PubMed
  24. Doyle D, Browne U, Brickley A, Murphy D. Vitamin D-induced hypercalcaemia and acute kidney injury in sarcoidosis. BMJ Case Rep 2023;16(1):e250580. PubMed
  25. Williamson A, Martineau AR, Sheikh A, Jolliffe D, Griffiths CJ. Vitamin D for the management of asthma. Cochrane Database Syst Rev 2023;2(2):CD011511. PubMed
  26. Kinesya E, Santoso D, Gde Arya N, et al. Vitamin D as adjuvant therapy for diabetic foot ulcers: Systematic review and meta-analysis approach. Clin Nutr ESPEN 2023;54:137-143. PubMed

See these in context on the Vitamin D monograph →

Quercetin 26 references
  1. Shoskes DA, Zeitlin SI, Shahed A, Rajfer J. Quercetin in men with category III chronic prostatitis: A preliminary prospective, double-blind, placebo-controlled trial. Urol 1999;54:960-3. PubMed
  2. Starvic B. Quercetin in our diet: from potent mutagen to probable anticarcinogen. Clin Biochem 1994;27:245-8. PubMed
  3. Ferry DR, Smith A, Malkhandi J, et al. Phase I clinical trial of the flavonoid quercetin: Pharmacokinetics and evidence for in vivo tyrosine kinase inhibition. Clin Cancer Res 1996;2:659-67..
  4. Obach RS. Inhibition of human cytochrome P450 enzymes by constituents of St. John's wort, an herbal preparation used in the treatment of depression. J Pharmacol Exp Ther 2000;294:88-95. DOI
  5. Edwards RL, Lyon T, Litwin SE, et al. Quercetin reduces blood pressure in hypertensive subjects. J Nutr 2007;137:2405-11.
  6. Kim KA, Park PW, Kim HK, et al. Effect of quercetin on the pharmacokinetics of rosiglitazone, a CYP2C8 substrate, in healthy subjects. J Clin Pharmacol 2005;45:941-6. PubMed
  7. DiCenzo R, Frerichs V, Larppanichpoonphol P, et al. Effect of quercetin on the plasma and intracellular concentrations of saquinavir in healthy adults. Pharmacotherapy 2006;26:1255-61. PubMed
  8. Choi JS, Choi BC, Choi KE. Effect of quercetin on the pharmacokinetics of oral cyclosporine. Am J Health Syst Pharm 2004;61:2406-9. PubMed
  9. Choi JS, Jo BW, Kim YC. Enhanced paclitaxel bioavailability after oral administration of paclitaxel or prodrug to rats pretreated with quercetin. Eur J Pharm Biopharm 2004;57:313-8. PubMed
  10. Vaclavikova R, Horsky S, Simek P, Gut I. Paclitaxel metabolism in rat and human liver microsomes is inhibited by phenolic antioxidants. Naunyn Schmiedebergs Arch Pharmacol 2003;368:200-9. PubMed
  11. Di Bari L, Ripoli S, Pradhan S, Salvadori P. Interactions between quercetin and warfarin for albumin binding: A new eye on food/drug interference. Chirality 2010;22:593-6. PubMed
  12. Lamson, D. W. and Brignall, M. S. Antioxidants and cancer, part 3: quercetin. Altern.Med.Rev. 2000;5(3):196-208.
  13. Duan KM, Wang SY, Ouyang W, Mao YM, Yang LJ. Effect of quercetin on CYP3A activity in Chinese healthy participants. J Clin Pharmacol 2012;52(6):940-6. PubMed
  14. Wang SY, Duan KM, Li Y, et al. Effect of quercetin on P-glycoprotein transport ability in Chinese healthy subjects. Eur J Clin Nutr 2013;67(4):390-4. PubMed
  15. Nguyen MA, Staubach P, Wolffram S, Langguth P. Effect of single-dose and short-term administration of quercetin on the pharmacokinetics of talinolol in humans - Implications for the evaluation of transporter-mediated flavonoid-drug interactions. Eur J Pha PubMed
  16. Wu LX, Guo CX, Chen WQ, et al. Inhibition of the organic anion-transporting polypeptide 1B1 by quercetin: an in vitro and in vivo assessment. Br J Clin Pharmacol 2012;73(5):750-7.
  17. Ahrens MJ, Thompson DL. Effect of emulin on blood glucose in type 2 diabetics. J Med Food. 2013;16(3):211-5. PubMed
  18. Larson A, Witman MA, Guo Y, et al. Acute, quercetin-induced reductions in blood pressure in hypertensive individuals are not secondary to lower plasma angiotensin-converting enzyme activity or endothelin-1: nitric oxide. Nutr Res. 2012;32(8):557-64. PubMed
  19. Bedada SK, Neerati P. Evaluation of the effect of quercetin treatment on CYP2C9 enzyme activity of diclofenac in healthy human volunteers. Phytother Res. 2018 Feb;32(2):305-311. doi: 10.1002/ptr.5978. PubMed
  20. Zhao Q, Wei J, Zhang H. Effects of quercetin on the pharmacokinetics of losartan and its metabolite EXP3174 in rats. Xenobiotica 2019;49(5):563-8. PubMed
  21. Bhutani P, Rajanna PK, Paul AT. Impact of quercetin on pharmacokinetics of quetiapine: insights from in-vivo studies in wistar rats. Xenobiotica. 2020:1-7.
  22. Li C, Wang X, Bi Y, et al. Potent Inhibitors of Organic Anion Transporters 1 and 3 From Natural Compounds and Their Protective Effect on Aristolochic Acid Nephropathy. Toxicol Sci. 2020;175(2):279-291. PubMed
  23. Ni Y, Duan Z, Zhou D, et al. Identification of Structural Features for the Inhibition of OAT3-Mediated Uptake of Enalaprilat by Selected Drugs and Flavonoids. Front Pharmacol. 2020;11:802. PubMed
  24. Song YK, Yoon JH, Woo JK, et al. Quercetin is a flavonoid breast cancer resistance protein inhibitor with an impact on the oral pharmacokinetics of sulfasalazine in rats. Pharmaceutics 2020;12(5):397. PubMed
  25. Ahmad E, Jahangir M, Ismail MA, et al. Influence of quercetin pretreatment on pharmacokinetics of warfarin in rats. Curr Drug Saf 2022. PubMed
  26. Nambiar A, Kellogg D 3rd, Justice J, et al. Senolytics dasatinib and quercetin in idiopathic pulmonary fibrosis: results of a phase I, single-blind, single-center, randomized, placebo-controlled pilot trial on feasibility and tolerability. EBioMedicine 20 PubMed

See these in context on the Quercetin monograph →

Vitamin C 51 references
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Back DJ, Breckenridge AM, MacIver M, et al. Interaction of ethinyloestradiol with ascorbic acid in man. Br Med J (Clin Res Ed) 1981;282:1516.
  3. Morris JC, Beeley L, Ballantine N. Interaction of ethinyloestradiol with ascorbic acid in man [letter]. Br Med J (Clin Res Ed) 1981;283:503.
  4. Labriola D, Livingston R. Possible interactions between dietary antioxidants and chemotherapy. Oncology 1999;13:1003-8.
  5. Dwyer JH, Merz NB, Shirocre AM, et al. Progression of early atherosclerosis and intake of vitamin C and vitamin E from supplements and food. The Los Angeles Atherosclerosis Study. 41st Annual Conference on Cardiovascular Disease Epidemiology and Prevent
  6. Levine M, Rumsey SC, Daruwala R, et al. Criteria and recommendations for vitamin C intake. JAMA 1999;281:1415-23. PubMed
  7. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  8. Segal S, Kaminski S. Drug-nutrient interactions. American Druggist 1996 Jul;42-8.
  9. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington, DC: National Academy Press, 2000. Available at: http://www.nap.edu/books/0309069351/html/.
  10. Houston JB, Levy G. Drug biotransformation interactions in man VI: Acetaminophen and ascorbic acid. J Pharm Sci 1976;65:1218-21. PubMed
  11. Brown BG, Zhao XQ, Chait A, et al. Simvastatin and niacin, antioxidant vitamins, or the combination for the prevention of coronary disease. N Engl J Med 2001;345:1583-93. DOI
  12. Rosenthal G. Interaction of ascorbic acid and warfarin. JAMA 1971;215:1671. DOI
  13. Hume R, Johnstone JM, Weyers E. Interaction of ascorbic acid and warfarin. JAMA 1972;219:1479. DOI
  14. Smith EC, Skalski RJ, Johnson GC, Rossi GV. Interaction of ascorbic acid and warfarin. JAMA 1972;221:1166. DOI
  15. Traxer O, Huet B, Poindexter J, et al. Effect of ascorbic acid consumption on urinary stone risk factors. J Urol 2003;170:397-401.. PubMed
  16. Domingo JL, Gomez M, Llobet JM, Richart C. Effect of ascorbic acid on gastrointestinal aluminum absorption (letter). Lancet 1991;338:1467.
  17. Domingo JL, Gomez M, Llobet JM, Corbella J. Influence of some dietary constituents on aluminum absorption and retention in rats. Kidney Int 1991;39:598-601. PubMed
  18. Partridge NA, Regnier FE, White JL, Hem SL. Influence of dietary constituents on intestinal absorption of aluminum. Kidney Int 1989;35:1413-7. PubMed
  19. Mc Leod DC, Nahata MC. Inefficacy of ascorbic acid as a urinary acidifier (letter). N Engl J Med 1977;296:1413. DOI
  20. Hansten PD, Hayton WL. Effect of antacid and ascorbic acid on serum salicylate concentration. J Clin Pharmacol 1980;20:326-31. PubMed
  21. Dysken MW, Cumming RJ, Channon RA, Davis JM. Drug interaction between ascorbic acid and fluphenazine. JAMA 1979;241:2008. DOI
  22. Vihtamaki T, Parantainen J, Koivisto AM, et al. Oral ascorbic acid increases plasma oestradiol during postmenopausal hormone replacement therapy. Maturitas 2002;42:129-35. PubMed
  23. Slain D, Amsden JR, Khakoo RA, et al. Effect of high-dose vitamin C on the steady-state pharmacokinetics of the protease inhibitor indinavir in healthy volunteers. Pharmacotherapy 2005;25:165-70. PubMed
  24. Cheung MC, Zhao XQ, Chait A, et al. Antioxidant supplements block the response of HDL to simvastatin-niacin therapy in patients with coronary artery disease and low HDL. Arterioscler Thromb Vasc Biol 2001;21:1320-6. PubMed
  25. Feetam CL, Leach RH, Meynell MJ. Lack of a clinically important interaction between warfarin and ascorbic acid. Toxicol Appl Pharmacol 1975;31:544-7. PubMed
  26. Weintraub M, Griner PF. Warfarin and ascorbic acid: lack of evidence for a drug interaction. Toxicol Appl Pharmacol 1974;28:53-6. PubMed
  27. Lee DH, Folsom AR, Harnack L, et al. Does supplemental vitamin C increase cardiovascular disease risk in women with diabetes? Am J Clin Nutr 2004;80:1194-200. PubMed
  28. Taylor EN, Stampfer MJ, Curhan GC. Dietary factors and the risk of incident kidney stones in men: new insights after 14 years of follow-up. J Am Soc Nephrol 2004;15:3225-32. PubMed
  29. Ward NC, Hodgson JM, Croft KD, et al. The combination of vitamin C and grape-seed polyphenols increases blood pressure: a randomized, double-blind, placebo-controlled trial. J Hypertens 2005;23:427-34.. PubMed
  30. Prasad KN. Rationale for using high-dose multiple dietary antioxidants as an adjunct to radiation therapy and chemotherapy. J Nutr 2004;134:3182S-3S. PubMed
  31. Conklin KA. Cancer chemotherapy and antioxidants. J Nutr 2004;134:3201S-3204S. PubMed
  32. Fairweather-Tait S, Hickson K, McGaw B, et al. Orange juice enhances aluminium absorption from antacid preparation. Eur J Clin Nutr. 1994;48(1):71-3.
  33. Gruenwald, J., Graubaum, H. J., Busch, R., and Bentley, C. Safety and tolerance of ester-C compared with regular ascorbic acid. Adv.Ther. 2006;23(1):171-178.
  34. Rahimi, R., Nikfar, S., Rezaie, A., and Abdollahi, M. A meta-analysis on the efficacy and safety of combined vitamin C and E supplementation in preeclamptic women. Hypertens.Pregnancy. 2009;28(4):417-434. PubMed
  35. Einerson, B., Nathorn, C., Kitiyakara, C., Sirada, M., and Thamlikitkul, V. The efficacy of ascorbic acid in suboptimal responsive anemic hemodialysis patients receiving erythropoietin: a meta-analysis. J Med.Assoc.Thai. 2011;94 Suppl 1:S134-S146.
  36. Li, G., Li, L., Yu, C., and Chen, L. Effect of vitamins C and E supplementation on Helicobacter pylori eradication: a meta-analysis. Br.J Nutr 2011;106(11):1632-1637.
  37. Chen X, Shen L, Gu X, et al. High-dose supplementation with vitamin C--induced pediatric urolithiasis: the first case report in a child and literature review. Urology. 2014;84(4):922-4. PubMed
  38. Sattar A, Willman JE, Kolluri R. Possible warfarin resistance due to interaction with ascorbic acid: case report and literature review. Am J Health Syst Pharm. 2013;70(9):782-6. PubMed
  39. Yaich S, Chaabouni Y, Charfeddine K, et al. Secondary oxalosis due to excess vitamin C intake: a cause of graft loss in a renal transplant recipient. Saudi J Kidney Dis Transpl. 2014;25(1):113-6. PubMed
  40. 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
  41. Rumbold A, Ota E, Nagata C, Shahrook S, Crowther CA. Vitamin C supplementation in pregnancy. Cochrane Database Syst Rev. 2015;(9):CD004072. PubMed
  42. Seo MS, Kim JK, Shim JY. High-dose vitamin C promotes regression of multiple pulmonary metastases originating from hepatocellular carcinoma. Yonsei Med J. 2015;56(5):1449-52. PubMed
  43. Skelin M, Lucijanic T, Amidzic Klaric D, et al. Factors Affecting Gastrointestinal Absorption of Levothyroxine: A Review. Clin Ther. 2017 Feb;39(2):378-403. PubMed
  44. Jiang K, Tang K, Liu H, Xu H, Ye Z, Chen Z. Ascorbic acid supplements and kidney stones incidence among men and women: a systematic review and meta-analysis. Urol J. 2019;16(2):115-120.
  45. Thomas S, Patel D, Bittel B, et al. Effect of High-Dose Zinc and Ascorbic Acid Supplementation vs Usual Care on Symptom Length and Reduction Among Ambulatory Patients With SARS-CoV-2 Infection: The COVID A to Z Randomized Clinical Trial. JAMA Netw Open. 2 PubMed
  46. Giffen MA, McLemore JL. Hyperoxalosis Secondary to Intravenous Vitamin C Administration as a Non-Allopathic Treatment for Cancer. Acad Forensic Pathol 2019;9(1-2):118-126. PubMed
  47. Maike A, Sturgill D, Gallan A. Oxalate Nephropathy in a Renal Transplant Recipient After Receiving High Dose Ascorbic Acid. Am J Med Sci 2021. PubMed
  48. Shen ZY, Chen YR, Wang MC, Chang SS. High-dose vitamin C-induced acute oxalate nephropathy in a renal transplant recipient: a case report and literature review. Asian J Surg 2022. PubMed
  49. Yanase F, Spano S, Maeda A, et al. Mega-dose sodium ascorbate: a pilot, single-dose, physiological effect, double-blind, randomized, controlled trial. Crit Care 2023;27(1):371. PubMed
  50. Sharma Y, Sumanadasa S, Shahi R, et al. Efficacy and safety of vitamin C supplementation in the treatment of community-acquired pneumonia: a systematic review and meta-analysis with trial sequential analysis. Sci Rep 2024;14(1):11846. PubMed
  51. Pejcic AV, Petrovic NZ, Djordjic MD, Milosavljevic MN. Vitamin C Levels in Pregnant Women and the Efficacy of Vitamin C Supplements in Preventing Premature Rupture of Membranes: A Systematic Review and Meta-Analysis. Balkan Med J 2024;41(4):248-260. PubMed

See these in context on the Vitamin C monograph →

Cassia Cinnamon 20 references
  1. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
  2. Khan A, Safdar M, Ali Khan M, et al. Cinnamon improves glucose and lipids of people with type 2 diabetes. Diabetes Care 2003;26:3215-8. PubMed
  3. De Benito V, Alzaga R. Occupational allergic contact dermatitis from cassia (Chinese cinnamon) as a flavouring agent in coffee. Contact Dermatitis 1999;40:165. PubMed
  4. Drake TE, Maibach HI. Allergic contact dermatitis and stomatitis caused by a cinnamic aldehyde-flavored toothpaste. Arch Dermatol 1976;112:202-3.
  5. Press release. Cinnamon capsules to reduce blood sugar are medicinal products! Efficacy has not been scientifically proven - some products contain high levels of coumarin. Federal Institute of Risk Assessment (BfM), Germany, November 11, 2006. Available a
  6. Felter SP, Vassallo JD, Carlton BD, Daston GP. A safety assessment of coumarin taking into account species-specificity of toxicokinetics. Food Chem Toxicol 2006;44:462-75. PubMed
  7. Crawford P. Effectiveness of cinnamon for lowering hemoglobin A1C in patients with type 2 diabetes: a randomized, controlled trial. J Am Board Fam Med 2009;22:507-12. PubMed
  8. Akilen, R., Tsiami, A., Devendra, D., and Robinson, N. Glycated haemoglobin and blood pressure-lowering effect of cinnamon in multi-ethnic Type 2 diabetic patients in the UK: a randomized, placebo-controlled, double-blind clinical trial. Diabet.Med. 2010; PubMed
  9. Lu T, Sheng H Wu J Cheng Y Zhu J Chen Y. Cinnamon extract improves fasting blood glucose and glycosylated hemoglobin level in Chinese patients with type 2 diabetes. Nutr Res. 2012;32(6):408-412. PubMed
  10. Choi, J., Lee, K. T., Ka, H., Jung, W. T., Jung, H. J., and Park, H. J. Constituents of the essential oil of the Cinnamomum cassia stem bark and the biological properties. Arch Pharm Res 2001;24(5):418-423.
  11. Altschuler JA, Casella SJ, MacKenzie TA, Curtis KM. The effect of cinnamon on A1C among adolescents with type 1 diabetes. Diabetes Care 2007;30(4):813-6. PubMed
  12. Stoecker BR, Zhan Z, Luo R, et al. Cinnamon extract lowers blood glucose in hyperglycemic subjects. FASEB J. 2010;22:722.1 (Abstract only). DOI
  13. Admani S, Hill H, Jacob SE. Cinnamon Sugar Scrub Dermatitis: "Natural" Is Not Always Best. Pediatr Dermatol. 2017;34(1):e42-e43. PubMed
  14. Isaac-Renton M, Li MK, Parsons LM. Cinnamon spice and everything not nice: many features of intraoral allergy to cinnamic aldehyde. Dermatitis. 2015;26(3):116-21. PubMed
  15. Vandersall A, Katta R. Eyelid dermatitis as a manifestation of systemic contact dermatitis to cinnamon. Dermatitis. 2015 Jul-Aug;26(4):189. PubMed
  16. Wickenberg J, Lindstedt S, Nilsson J, Hlebowicz J. Cassia cinnamon does not change the insulin sensitivity or the liver enzymes in subjects with impaired glucose tolerance. Nutr J 2014 Sep 24;13:96. PubMed
  17. Brancheau D, Patel B, Zughaib M. Do cinnamon supplements cause acute hepatitis? Am J Case Rep 2015;16:250-4. PubMed
  18. Shekarchizadeh-Esfahani P, Heydarpour F, Izadi F, Jalili C. The effect of cinnamon supplementation on liver enzymes in adults: A systematic review and meta-analysis of randomized controlled trials. Complement Ther Med 2021;58:102699. PubMed
  19. Bernaola J, Valverde-Monge M, Otal-Buesa M, Cullen D, Heras-Mendaza F. Cinnamon allergic contact cheilitis. Contact Dermatitis 2023;88(5):418-419. PubMed
  20. Patel K, Howard M, Tate B. Cheilitis caused by allergic contact dermatitis to cinnamon in chai tea: A case report. Contact Dermatitis 2023;88(3):239-240. PubMed

See these in context on the Cassia Cinnamon monograph →

Magnesium 82 references
  1. Rodin SM, Johnson BF. Pharmacokinetic interactions with digoxin. Clin Pharmacokinet 1988;15:227-44.
  2. Covington TR, et al. Handbook of Nonprescription Drugs. 11th ed. Washington, DC: American Pharmaceutical Association, 1996.
  3. Dahle LO, Berg G, Hammar M, et al. The effect of oral magnesium substitution on pregnancy-induced leg cramps. Am J Obstet Gynecol 1995;173:175-80. PubMed
  4. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  5. Peikert A, Wilimzig C, Kohne-Volland R. Prophylaxis of migraine with oral magnesium: results from a prospective, multi-center, placebo-controlled and double-blind randomized study. Cephalalgia 1996;16:257-63. PubMed
  6. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. Washington, DC: National Academy Press, 1999. Available at: http://books.nap.edu/books/0309063507/html/index.html.
  7. Birrer RB, Shallash AJ, Totten V. Hypermagnesemia-induced fatality following epsom salt gargles. J Emerg Med 2002;22:185-8. PubMed
  8. Ryan MP. Diuretics and potassium/magnesium depletion. Directions for treatment. Am J Med 1987;82:38-47.. PubMed
  9. Hollifield JW. Magnesium depletion, diuretics, and arrhythmias. Am J Med 1987;82:30-7.. PubMed
  10. Heidenreich O. Mode of action of conventional and potassium-sparing diuretics--aspects with relevance to Mg-sparing effects. Magnesium 1984;3:248-56..
  11. Pfaffenrath V, Wessely P, Meyer C, et al. Magnesium in the prophylaxis of migraine--a double-blind placebo-controlled study. Cephalalgia 1996;16:436-40.. PubMed
  12. Wang F, Van Den Eeden SK, Ackerson LM, et al. Oral magnesium oxide prophylaxis of frequent migrainous headache in children: a randomized, double-blind, placebo-controlled trial. Headache 2003;43:601-10.. PubMed
  13. Sompolinsky D, Samra Z. Influence of magnesium and manganese on some biological and physical properties of tetracycline. J Bacteriol 1972;110:468-76.. PubMed
  14. Jeyabalan A, Caritis SN. Pharmacologic inhibition of preterm labor. Clin Obstet Gynecol 2002;45:99-113. PubMed
  15. Mittendorf R, Dambrosia J, Pryde PG, et al. Association between the use of antenatal magnesium sulfate in preterm labor and adverse health outcomes in infants. Am J Obstet Gynecol 2002;186:1111-8.. PubMed
  16. Witlin AG, Sibai BM. Magnesium sulfate therapy in preeclampsia and eclampsia. Obstet Gynecol 1998;92:883-9.. DOI
  17. Crowther CA, Hiller JE, Doyle LW. Magnesium sulphate for preventing preterm birth in threatened preterm labour. Cochrane Database Syst Rev 2002;4:CD001060. . PubMed
  18. Davey MJ, Teubner D. A randomized controlled trial of magnesium sulfate, in addition to usual care, for rate control in atrial fibrillation. Ann Emerg Med 2005;45:347-53.. PubMed
  19. L'Hommedieu CS, Nicholas D, Armes DA, et al. Potentiation of magnesium sulfate--induced neuromuscular weakness by gentamicin, tobramycin, and amikacin. J Pediatr 1983;102:629-31..
  20. Dunn CJ, Goa KL. Risedronate: a review of its pharmacological properties and clinical use in resorptive bone disease. Drugs 2001;61:685-712..
  21. Kass L, Weekes J, Carpenter L. Effect of magnesium supplementation on blood pressure: a meta-analysis. Eur J Clin Nutr 2012;66:411-8. PubMed
  22. Koontz SL, Friedman SA, Schwartz ML. Symptomatic hypocalcemia after tocolytic therapy with magnesium sulfate and nifedipine. Am J Obstet Gynecol. 2004;190(6):1773-6. PubMed
  23. Snyder SW, Cardwell MS. Neuromuscular blockade with magnesium sulfate and nifedipine. Am J Obstet Gynecol. 1989;161(1):35-6. PubMed
  24. Waisman GD, Mayorga LM, Cámera MI, et al. Magnesium plus nifedipine: potentiation of hypotensive effect in preeclampsia? Am J Obstet Gynecol. 1988;159(2):308-9. PubMed
  25. Brown DD, Juhl RP. Decreased bioavailability of digoxin due to antacids and kaolin-pectin. N Engl J Med. 1976;295(19):1034-7. PubMed
  26. Allen MD, Greenblatt DJ, Harmatz JS, et al. Effect of magnesium--aluminum hydroxide and kaolin--pectin on absorption of digoxin from tablets and capsules. J Clin Pharmacol. 1981;21(1):26-30. PubMed
  27. Ravn HB, Vissinger H, Kristensen SD, et al. Magnesium inhibits platelet activity--an in vitro study. Thromb Haemost. 1996;76(1):88-93. DOI
  28. Ravn HB, Kristensen SD, Vissinger H, et al. Magnesium inhibits human platelets. Blood Coagul Fibrinolysis. 1996;7(2):241-4. PubMed
  29. Ravn HB, Vissinger H, Kristensen SD, et al. Magnesium inhibits platelet activity--an infusion study in healthy volunteers. Thromb Haemost. 1996;75(6):939-44. DOI
  30. Neuvonen PJ, Kivistö KT. The effects of magnesium hydroxide on the absorption and efficacy of two glibenclamide preparations. Br J Clin Pharmacol. 1991;32(2):215-20. PubMed
  31. Kivistö KT, Neuvonen PJ. Enhancement of absorption and effect of glipizide by magnesium hydroxide. Clin Pharmacol Ther. 1991;49(1):39-43. PubMed
  32. Neuvonen PJ, Kivistö KT. Enhancement of drug absorption by antacids. An unrecognised drug interaction. Clin Pharmacokinet. 1994;27(2):120-8. PubMed
  33. Shechter, M., Merz, C. N., Paul-Labrador, M., Meisel, S. R., Rude, R. K., Molloy, M. D., Dwyer, J. H., Shah, P. K., and Kaul, S. Beneficial antithrombotic effects of the association of pharmacological oral magnesium therapy with aspirin in coronary heart
  34. Ganzevoort, J. W., Hoogerwaard, E. M., and van der Post, J. A. [Hypocalcemic delirium due to magnesium sulphate therapy in a pregnant woman with pre-eclampsia]. Ned.Tijdschr.Geneeskd. 8-3-2002;146(31):1453-1456.
  35. Horner, S. M. Efficacy of intravenous magnesium in acute myocardial infarction in reducing arrhythmias and mortality. Meta-analysis of magnesium in acute myocardial infarction. Circulation 1992;86(3):774-779. PubMed
  36. Azria, E., Tsatsaris, V., Goffinet, F., Kayem, G., Mignon, A., and Cabrol, D. [Magnesium sulfate in obstetrics: current data]. J Gynecol.Obstet.Biol.Reprod.(Paris) 2004;33(6 Pt 1):510-517.
  37. Magee, L. A., Miremadi, S., Li, J., Cheng, C., Ensom, M. H., Carleton, B., Cote, A. M., and von Dadelszen, P. Therapy with both magnesium sulfate and nifedipine does not increase the risk of serious magnesium-related maternal side effects in women with p
  38. Henyan, N. N., Gillespie, E. L., White, C. M., Kluger, J., and Coleman, C. I. Impact of intravenous magnesium on post-cardiothoracic surgery atrial fibrillation and length of hospital stay: a meta-analysis. Ann.Thorac.Surg. 2005;80(6):2402-2406. PubMed
  39. Li, J., Zhang, Q., Zhang, M., and Egger, M. Intravenous magnesium for acute myocardial infarction. Cochrane.Database.Syst.Rev. 2007;(2):CD002755. PubMed
  40. Doyle, L. W., Crowther, C. A., Middleton, P., Marret, S., and Rouse, D. Magnesium sulphate for women at risk of preterm birth for neuroprotection of the fetus. Cochrane.Database.Syst.Rev. 2009;(1):CD004661. PubMed
  41. Han, S., Crowther, C. A., and Moore, V. Magnesium maintenance therapy for preventing preterm birth after threatened preterm labour. Cochrane.Database.Syst.Rev. 2010;(7):CD000940. PubMed
  42. Duley, L., Gulmezoglu, A. M., Henderson-Smart, D. J., and Chou, D. Magnesium sulphate and other anticonvulsants for women with pre-eclampsia. Cochrane.Database.Syst.Rev. 2010;(11):CD000025. PubMed
  43. Conde-Agudelo, A., Romero, R., and Kusanovic, J. P. Nifedipine in the management of preterm labor: a systematic review and metaanalysis. Am J Obstet.Gynecol. 2011;204(2):134-20. PubMed
  44. Wong, G. K., Boet, R., Poon, W. S., Chan, M. T., Gin, T., Ng, S. C., and Zee, B. C. Intravenous magnesium sulphate for aneurysmal subarachnoid hemorrhage: an updated systemic review and meta-analysis. Crit Care 2011;15(1):R52. PubMed
  45. Magee, L., Sawchuck, D., Synnes, A., and von, Dadelszen P. SOGC Clinical Practice Guideline. Magnesium sulphate for fetal neuroprotection. J Obstet.Gynaecol.Can. 2011;33(5):516-529.
  46. Doyle, L. W. Antenatal magnesium sulfate and neuroprotection. Curr Opin Pediatr 2012;24(2):154-159. PubMed
  47. McDonald, S. D., Lutsiv, O., Dzaja, N., and Duley, L. A systematic review of maternal and infant outcomes following magnesium sulfate for pre-eclampsia/eclampsia in real-world use. Int J Gynaecol.Obstet. 2012;118(2):90-96. PubMed
  48. Gordon, M., Naidoo, K., Akobeng, A. K., and Thomas, A. G. Osmotic and stimulant laxatives for the management of childhood constipation. Cochrane.Database.Syst.Rev. 2012;7:CD009118. PubMed
  49. Dodd, J. M., Crowther, C. A., and Middleton, P. Oral betamimetics for maintenance therapy after threatened preterm labour. Cochrane.Database.Syst.Rev. 2012;12:CD003927. PubMed
  50. Wu, X., Wang, C., Zhu, J., Zhang, C., Zhang, Y., and Gao, Y. Meta-analysis of randomized controlled trials on magnesium in addition to beta-blocker for prevention of postoperative atrial arrhythmias after coronary artery bypass grafting. BMC.Cardiovasc.D PubMed
  51. Thorp, J. M., Jr., Katz, V. L., Campbell, D., and Cefalo, R. C. Hypersensitivity to magnesium sulfate. Am.J.Obstet.Gynecol. 1989;161(4):889-890. PubMed
  52. Duley L and Gulmezoglu AM. Magnesium sulphate versus lytic cocktail for eclampsia. Cochrane Database of Systematic Reviews 2000;(3) PubMed
  53. Gibbins KJ, Browning KR, Lopes VV, Anderson BL, Rouse DJ. Evaluation of the clinical use of magnesium sulfate for cerebral palsy prevention. Obstet Gynecol 2013;121(2 Pt 1):235-40. PubMed
  54. Ji D. Oral magnesium sulfate causes perforation during bowel preparation for fiberoptic colonoscopy in patients with colorectal cancer. J Emerg Med 2012;43(4):716-7. PubMed
  55. Yagi T, Naito T, Mino Y, Umemura K, Kawakami J. Impact of concomitant antacid administration on gabapentin plasma exposure and oral bioavailability in healthy adult subjects. Drug Metab Pharmacokinet 2012;27(2):248-54. PubMed
  56. Yamasaki M, Funakoshi S, Matsuda S, Imazu T, Takeda Y, Murakami T, Maeda Y. Interaction of magnesium oxide with gastric acid secretion inhibitors in clinical pharmacotherapy. Eur J Clin Pharmacol 2014;70(8):921-4. PubMed
  57. Choi ES, Jeong WJ, Ahn SH, Oh AY, Jeon YT, Do SH. Magnesium sulfate accelerates the onset of low-dose rocuronium in patients undergoing laryngeal microsurgery. J Clin Anesth. 2017 Feb;36:102-106. PubMed
  58. Ikee R, Toyoyama T, Endo T, Tsunoda M, Hashimoto N. Impact of sevelamer hydrochloride on serum magnesium concentrations in hemodialysis patients. Magnes Res. 2016 Apr 1;29(4):184-90. PubMed
  59. Miller ES, Sakowicz A, Leger E. Lange E, Yee LM. The association between receipt of intrapartum magnesium and postpartum hemorrhage. Am J Obstet Gynecol 2018;218(1 Suppl):S165.
  60. Rodríguez-Rubio L, Solis Garcia Del Pozo J, Nava E, Jordán J. Interaction between magnesium sulfate and neuromuscular blockers during the perioperative period. A systematic review and meta-analysis. J Clin Anesth. 2016;34:524-34. PubMed
  61. Brown RS. Magnesium Sulfate: Another Cause of a Solute Diuresis. Am J Kidney Dis. 2017;69(4):550-551. PubMed
  62. Park H, Qin R, Smith TJ, et al. North Central Cancer Treatment Group N10C2 (Alliance): a double-blind placebo-controlled study of magnesium supplements to reduce menopausal hot flashes. Menopause. 2015;22(6):627-32. PubMed
  63. Sakanoue M, Sanada J, Kanekura T. Skin eruption elicited by magnesium oxide (Maglax). J Dermatol. 2016;43(2):221-2.
  64. Iwamuro M, Saito S, Yoshioka M, et al. A Magnesium Oxide Bezoar. Intern Med. 2018;57(21):3087-3091. PubMed
  65. Vilchez G, Dai J, Kumar K, Mundy D, Kontopoulos E, Sokol RJ. Racial/ethnic disparities in magnesium sulfate neuroprotection: a subgroup analysis of a multicenter randomized controlled trial. J Matern Fetal Neonatal Med. 2018;31(17):2304-2311. PubMed
  66. Drug Safety Communication: FDA Recommends Against Prolonged Use of Magnesium Sulfate to Stop Pre-term Labor Due to Bone Changes in Exposed Babies. U.S. Food and Drug Administration (FDA), May 30, 2013. https://www.fda.gov/downloads/Drugs/DrugSafety/UCM353
  67. Committee Opinion: Magnesium Sulfate Use in Obstetrics. The American College of Obstetricians and Gynecologists Committee on Obstetric Practice Society for Maternal-Fetal Medicine, Number 652, January 2016. https://www.acog.org/Clinical-Guidance-and-Publi
  68. Kashihara Y, Terao Y, Yoda K, et al. Effects of magnesium oxide on pharmacokinetics of L-dopa/carbidopa and assessment of pharmacodynamic changes by a model-based simulation. Eur J Clin Pharmacol. 2019;75(3):351-361. PubMed
  69. Shepherd E, Salam RA, Manhas D, et al. Antenatal magnesium sulphate and adverse neonatal outcomes: A systematic review and meta-analysis. PLoS Med. 2019;16(12):e1002988. PubMed
  70. Hong JY, Hong JY, Choi YS, et al. Antenatal magnesium sulfate treatment and risk of necrotizing enterocolitis in preterm infants born at less than 32 weeks of gestation. Sci Rep. 2020;10(1):12826. PubMed
  71. Schuh S, Sweeney J, Rumantir M, et al. Effect of nebulized magnesium vs placebo added to albuterol on hospitalization among children with refractory acute asthma treated in the emergency department: a randomized clinical trial. JAMA. 2020;324(20):2038-20 PubMed
  72. Almeida CED, Carvalho LR, Andrade CVC, Nascimento PD Jr, Barros GAM, Modolo NSP. Effects of magnesium sulphate on the onset time of rocuronium at different doses: a randomized clinical trial. Braz J Anesthesiol. 2021;71(5):482-8. PubMed
  73. Gochi Valdovinos A, Arriaga-Redondo M, Dejuan Bitriá E, Pérez Rodríguez I, Márquez Isidro E, Blanco Bravo D. Prenatal therapy with magnesium sulphate and intestinal obstruction due to meconium in preterm newborns. An Pediatr (Engl Ed). 2022 Feb;96(2):138- PubMed
  74. Iio K, Kondo E, Shibata E, et al. Long-term tocolysis with magnesium sulfate as a risk factor for low bone mass: a case series. J Med Cases. 2022 Feb;13(2):47-50. PubMed
  75. Eiraku K, Uozumi Y, Hieda M, Maruyama T, Nomura H. A senile case of heart failure associated with hypermagnesemia induced by magnesium-containing laxative agent. Geriatr Gerontol Int. 2022;22(10):897-899.
  76. Enayati A, Gin JH, Sajeev JK, et al. Efficacy of intravenous magnesium for the management of non-post operative atrial fibrillation with rapid ventricular response: A systematic review and meta-analysis. J Cardiovasc Electrophysiol 2023;34(5):1286-1295. PubMed
  77. Su YH, Luo DC, Pang Y. Effects of intraoperative Magnesium sulfate infusion on emergency agitation during general anesthesia in patients undergoing radical mastectomy: a randomized controlled study. BMC Anesthesiol 2023;23(1):326. PubMed
  78. Han J, Park HY, Shin HJ, Chung SH, Do SH. Effects of magnesium sulphate on neostigmine-induced recovery from moderate neuromuscular blockade with rocuronium: a randomized controlled trial. Magnes Res 2023;36(2):31-39. PubMed
  79. Lee AT, Cordova JC, Jamplis RP, Pomicter GR. Posterior Reversible Encephalopathy Syndrome and Eclampsia in the Setting of Magnesium Toxicity: A Case Report. A A Pract 2023;17(11):e01726. PubMed
  80. Darmawan D, Rengganis I, Rumende CM, et al. Effectiveness and Safety of Nebulized Magnesium as Last Line Treatment in Adults with Acute Asthma Attack: A Systematic Review and Meta-Analysis. Acta Med Indones 2024;56(1):3-12.
  81. Shepherd ES, Goldsmith S, Doyle LW, et al. Magnesium sulphate for women at risk of preterm birth for neuroprotection of the fetus. Cochrane Database Syst Rev 2024;5(5):CD004661. PubMed
  82. US Food and Drug Administration (FDA). Biktarvy Prescribing Information. October 2024. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/210251Orig1s020lbl.pdf. Accessed July 16, 2025.

See these in context on the Magnesium monograph →

Cranberry 33 references
  1. Anon. Possible interaction between warfarin and cranberry juice. Current Problems in Pharmacovigilance 2003;29:8. PubMed
  2. Greenblatt DJ, von Moltke LL, Perloff ES, et al. Interaction of flurbiprofen with cranberry juice, grape juice, tea, and fluconazole: in vitro and clinical studies. Clin Pharmacol Ther 2006;79:125-33. PubMed
  3. Hodek P, Trefil P, Stiborova M. Flavonoids-potent and versatile biologically active compounds interacting with cytochromes P450. Chem Biol Interact 2002;139:1-21.. PubMed
  4. Grant P. Warfarin and cranberry juice: An interaction? J Heart Valve Dis 2004;13:25-6.
  5. Suvarna R, Pirmohamed M, Henderson L. Possible interaction between warfarin and cranberry juice. BMJ 2003;327:1454. PubMed
  6. Li Z, Seeram NP, Carpenter CL, et al. Cranberry does not affect prothrombin time in male subjects on warfarin. J Am Diet Assoc 2006;106:2057-61. PubMed
  7. Lilja JJ, Backman JT, Neuvonen PJ. Effects of daily ingestion of cranberry juice on the pharmacokinetics of warfarin, tizanidine, and midazolam - probes of CYP2C9, CYP1A2 and CYP3A4. Clin Pharmacol The 2007:81:833-9. PubMed
  8. Wing DA, Rumney PJ, Preslicka CW, Chung JH. Daily cranberry juice for the prevention of asymptomatic bacteriuria in pregnancy: a randomized, controlled pilot study. J Urol 2008;180:1367-72. PubMed
  9. Mohammed Abdul MI, Jiang X, Williams KM, et al. Pharmacodynamic interaction of warfarin with cranberry but not with garlic in healthy subjects. Br J Pharmacol 2008;154:1691-700. PubMed
  10. McMurdo MET, Argo I, Phillips G, et al. Cranberry or trimethoprim for the prevention of recurrently urinary tract infections? A randomized controlled trial in older women. J Antimicrob Chemother 2009;63:389-95.
  11. Mergenhagen KA, Sherman O. Elevated International Normalized Ratio after concurrent ingestion of cranberry sauce and warfarin. Am J Health-Syst Pharm 2008;65:2113-6. PubMed
  12. Ansell J, McDonough M, Zhao Y, et al. The absence of an interaction between warfarin and cranberry juice: a randomized, double-blind trial. J Clin Pharmacol 2009;49:824-30. PubMed
  13. Haber SL, Cauthon KA, Raney EC. Cranberry and warfarin interaction: a case report and review of the literature. Consult Pharm 2012;27:58-65. PubMed
  14. Hamann GL, Campbell JD, George CM. Warfarin-cranberry juice interaction. Ann Pharmacother 2011;45:e17. PubMed
  15. Roberts D, Flanagan P. Case report: Cranberry juice and warfarin. Home Healthc Nurse 2011;29:92-7.
  16. Garcia-Calatayud, S., Larreina Cordoba, J. J., and Lozano De La Torre MJ. [Severe cranberry juice poisoning]. An.Esp.Pediatr. 2002;56(1):72-73.
  17. Patel, D. A., Gillespie, B., Sobel, J. D., Leaman, D., Nyirjesy, P., Weitz, M. V., and Foxman, B. Risk factors for recurrent vulvovaginal candidiasis in women receiving maintenance antifungal therapy: results of a prospective cohort study. Am J Obstet.Gy PubMed
  18. Isele, H. [Fatal bleeding under warfarin plus cranberry juice. Is it due to salicylic acid?]. MMW.Fortschr.Med 3-11-2004;146(11):13.
  19. Linsenmeyer, T. A., Harrison, B., Oakley, A., Kirshblum, S., Stock, J. A., and Millis, S. R. Evaluation of cranberry supplement for reduction of urinary tract infections in individuals with neurogenic bladders secondary to spinal cord injury. A prospecti
  20. McMurdo, M. E., Bissett, L. Y., Price, R. J., Phillips, G., and Crombie, I. K. Does ingestion of cranberry juice reduce symptomatic urinary tract infections in older people in hospital? A double-blind, placebo-controlled trial. Age Ageing 2005;34(3):256- PubMed
  21. Sylvan, L. and Justice, N. P. Possible interaction between warfarin and cranberry juice. Am Fam.Physician 9-15-2005;72(6):1000.
  22. Niklasson, A. and Andren, L. [Interaction between Waran and cranberry juice]. Lakartidningen 3-15-2006;103(11):853-854.
  23. Rindone, J. P. and Murphy, T. W. Warfarin-cranberry juice interaction resulting in profound hypoprothrombinemia and bleeding. Am J Ther 2006;13(3):283-284. PubMed
  24. Uesawa, Y. and Mohri, K. Effects of cranberry juice on nifedipine pharmacokinetics in rats. J Pharm Pharmacol 2006;58(8):1067-1072. PubMed
  25. Valentova, K., Stejskal, D., Bednar, P., Vostalova, J., Cihalik, C., Vecerova, R., Koukalova, D., Kolar, M., Reichenbach, R., Sknouril, L., Ulrichova, J., and Simanek, V. Biosafety, antioxidant status, and metabolites in urine after consumption of dried
  26. Royer, D. J., George, J. N., and Terrell, D. R. Thrombocytopenia as an adverse effect of complementary and alternative medicines, herbal remedies, nutritional supplements, foods, and beverages. Eur J Haematol 2010;84(5):421-429. PubMed
  27. Stapleton, A. E., Dziura, J., Hooton, T. M., Cox, M. E., Yarova-Yarovaya, Y., Chen, S., and Gupta, K. Recurrent urinary tract infection and urinary Escherichia coli in women ingesting cranberry juice daily: a randomized controlled trial. Mayo.Clin.Proc. PubMed
  28. Doad GJ, Kabange W. Cranberry juice, atorvastatin and back pain. J Med Assoc Ga 2014;103(1):14.
  29. Griffiths AP, Beddall A, Pegler S. Fatal haemopericardium and gastrointestinal haemorrhage due to possible interaction of cranberry juice with warfarin. J R Soc Promot Health 2008;128(6):324-6. PubMed
  30. Mellen CK, Ford M, Rindone JP. Effect of high-dose cranberry juice on the pharmacodynamics of warfarin in patients. Br J Clin Pharmacol 2010;70(1):139-42. PubMed
  31. Ushijima K, Tsuruoka S, Tsuda H, Hasegawa G, Obi Y, Kaneda T, Takahashi M, Maekawa T, Sasaki T, Koshimizu TA, Fujimura A. Cranberry juice suppressed the diclofenac metabolism by human liver microsomes, but not in healthy human subjects. Br J Clin Pharmaco PubMed
  32. Ngo N, Brantley SJ, Carrizosa DR, et al. The warfarin-cranberry juice interaction revisited: A systematic in vitro-in vivo evaluation. J Exp Pharmacol. 2010;2010(2):83-91.
  33. Williams G, Stothart CI, Hahn D, Stephens JH, Craig JC, Hodson EM. Cranberries for preventing urinary tract infections. Cochrane Database Syst Rev 2023;11(11):CD001321. PubMed

See these in context on the Cranberry monograph →

Elderberry 6 references
  1. Barak V, Halperin T, Kalickman I. The effect of Sambucol, a black elderberry-based, natural product, on the production of human cytokines: I. Inflammatory cytokines. Eur Cytokine Netw 2001;12:290-6..
  2. Elderberry (Sambucus species). The Poison Plant Patch, Novia Scotia Museum, 2007. Available at: http://museum.gov.ns.ca/poison/?section=species&id=117 (Accessed 16 October 2009).
  3. European elder. Canadian Poisonous Plants Information System. Available at: http://www.cbif.gc.ca/pls/pp/ppack.jump?p_null=all&p_psn=121&p_type=all&p_sci=comm&p_x=px (Accessed 16 October 2009).
  4. Raus K, Pleschka S, Klein P, Schoop R, Fisher P. Effect of an echinacea-based hot drink versus oseltamivir in Influenza treatment: a randomized, double-blind, double-dummy, multicenter, noninferiority clinical trial. . Curr Ther Res Clin Exp. 2015;20;77:6 PubMed
  5. Ramachandran A, Antala D, Pudasainee P, Panginikkod S, Gupta H. A Plausible Association Between the Use of Elderberry and Autoimmune Hepatitis. Cureus 2022;14(4):e24250. PubMed
  6. Agarwal N, Mangla A. Elderberry interaction with pazopanib in a patient with soft-tissue sarcoma: A case report and literature review. Mol Clin Oncol 2024;20(5):36. PubMed

See these in context on the Elderberry monograph →

Apple 16 references
  1. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  2. Bailey DG, Dresser GK, Munoz C, et al. Reduction of fexofenadine bioavailability by fruit juices. Clin Pharmacol Ther 2001;69:P21.
  3. Rodriguez J, Crespo JF, Lopez-Rubio A, et al. Clinical cross-reactivity among foods of the Rosaceae family. J Allergy Clin Immunol 2000;106:183-189. PubMed
  4. Greenblatt DJ. Analysis of drug interactions involving fruit beverages and organic anion-transporting polypeptides. J Clin Pharmacol 2009;49:1403-7. PubMed
  5. Bailey DG. Fruit juice inhibition of uptake transport: a new type of food-drug interaction. Br J Clin Pharmacol 2010;70:645-55. PubMed
  6. Kamath AV, Yao M, Zhang Y, Chong S. Effect of fruit juices on the oral bioavailability of fexofenadine in rats. J Pharm Sci 2005;94:233-9. PubMed
  7. Tapaninen T, Neuvonen PJ, Niemi M. Orange and apple juice greatly reduce the plasma concentrations of the OATP2B1 substrate aliskiren. Br J Clin Pharmacol 2011;71:718-26. PubMed
  8. Jeon H, Jang IJ, Lee S, et al. Apple juice greatly reduces systemic exposure to atenolol. Br J Clin Pharmacol 2012 May 11. doi: 10.1111/j.1365-2125.2012.04324.x. [Epub ahead of print]. PubMed
  9. Visvanathan, R., Chen, R., Horowitz, M., and Chapman, I. Blood pressure responses in healthy older people to 50 g carbohydrate drinks with differing glycaemic effects. Br J Nutr 2004;92(2):335-340. PubMed
  10. Asp, N. G., Agardh, C. D., Ahren, B., Dencker, I., Johansson, C. G., Lundquist, I., Nyman, M., Sartor, G., and Schersten, B. Dietary fibre in type II diabetes. Acta Med Scand Suppl 1981;656:47-50. PubMed
  11. Akamine Y, Miura M, Komori H, et al. Effects of one-time apple juice ingestion on the pharmacokinetics of fexofenadine enantiomers. Eur J Clin Pharmacol. 2014 Sep;70(9):1087-95. PubMed
  12. Luo J, Imai H, Ohyama T, et al. The Pharmacokinetic Exposure to Fexofenadine is Volume-Dependently Reduced in Healthy Subjects Following Oral Administration With Apple Juice. Clin Transl Sci. 2016 Aug;9(4):201-6. PubMed
  13. Tsiougkos N, Vovolis V. Repeated anaphylactic episodes to orange and apple. Eur Ann Allergy Clin Immunol. 2013 May;45(3):113-5.
  14. Rubido S, García-Caballero L, Abeleira MT, Limeres J, García M, Diz P. Effect of chewing an apple on dental plaque removal and on salivary bacterial viability. PLoS One. 2018;13(7):e0199812. PubMed
  15. Krishnasamy S, Lomer MCE, Marciani L, et al. Processing apples to puree or juice speeds gastric emptying and reduces postprandial intestinal volumes and satiety in healthy adults. J Nutr 2020;150(11):2890-9. PubMed
  16. Awan S, Abelleira A, Khehra L, Hieber R. Undetectable serum lithium concentrations after coadministration of liquid lithium citrate and apple juice: A case report. Ment Health Clin. 2021;11(1):27-30. PubMed

See these in context on the Apple monograph →

Maritime Pine 14 references
  1. Rice-Evans CA, Packer L, eds. Flavonoids in Health and Disease. Manhattan, NY: Marcel Dekker, Inc., 1998.
  2. Liu FJ, Zhang YX, Lau BH. Pycnogenol enhances immune and haemopoietic functions in senescence-accelerated mice. Cell Mol Life Sci 1998;54:1168-72. PubMed
  3. Putter M, Grotemeyer KH, Wurthwein G, et al. Inhibition of smoking-induced platelet aggregation by aspirin and pycnogenol. Thromb Res 1999;95:155-61. PubMed
  4. Kohama T, Inoue M. Pycnogenol alleviates pain associated with pregnancy. Phytother Res 2006;20:232-4.
  5. Liu X, Zhou HJ, Rohdewald P. French maritime pine bark extract pycnogenol dose-dependently lowers glucose in type 2 diabetic patients (letter). Diabetes Care 2004;27:839. PubMed
  6. Liu X, Wei J, Tan F, et al. Antidiabetic effect of Pycnogenol French maritime pine bark extract in patients with diabetes type II. Life Sci 2004;75:2505-13. PubMed
  7. Wilson D, Evans M, Guthrie N et al. A randomized, double-blind, placebo-controlled exploratory study to evaluate the potential of pycnogenol for improving allergic rhinitis symptoms. Phytother Res 2010;24:1115-9.
  8. Araghi-Niknam, M., Hosseini, S., Larson, D., Rohdewald, P., and Watson, R. R. Pine bark extract reduces platelet aggregation. Integr.Med. 3-21-2000;2(2):73-77. PubMed
  9. Trebaticka, J., Kopasova, S., Hradecna, Z., Cinovsky, K., Skodacek, I., Suba, J., Muchova, J., Zitnanova, I., Waczulikova, I., Rohdewald, P., and Durackova, Z. Treatment of ADHD with French maritime pine bark extract, Pycnogenol. Eur.Child Adolesc.Psychi PubMed
  10. Suzuki, N., Uebaba, K., Kohama, T., Moniwa, N., Kanayama, N., and Koike, K. French maritime pine bark extract significantly lowers the requirement for analgesic medication in dysmenorrhea: a multicenter, randomized, double-blind, placebo-controlled study
  11. Cisar, P., Jany, R., Waczulikova, I., Sumegova, K., Muchova, J., Vojtassak, J., Durackova, Z., Lisy, M., and Rohdewald, P. Effect of pine bark extract (Pycnogenol) on symptoms of knee osteoarthritis. Phytother.Res. 2008;22(8):1087-1092.
  12. Enseleit, F., Sudano, I., Periat, D., Winnik, S., Wolfrum, M., Flammer, A. J., Frohlich, G. M., Kaiser, P., Hirt, A., Haile, S. R., Krasniqi, N., Matter, C. M., Uhlenhut, K., Hogger, P., Neidhart, M., Luscher, T. F., Ruschitzka, F., and Noll, G. Effects
  13. Schoonees, A., Visser, J., Musekiwa, A., and Volmink, J. Pycnogenol(R) (extract of French maritime pine bark) for the treatment of chronic disorders. Cochrane.Database.Syst.Rev. 2012;4:CD008294.
  14. Wang S, Tan D Zhao Y et al. The effect of pycnogenol on the microcirculation, platelet function and ischemic myocardium in patients with coronary artery diseases. Eur Bull Drug Res 1999;7:19-25.

See these in context on the Maritime Pine monograph →

Sweet Orange 17 references
  1. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  2. FDA, CFSAN. FDA-approved potassium health claim notification for potassium containing foods. 2000. Available at: www.cfsan.fda.gov/~dms/hclm-k.html.
  3. Kurowska EM, Spence JD, Jordan J, et al. HDL-cholesterol-raising effect of orange juice in subjects with hypercholesterolemia. Am J Clin Nutr 2000;72:1095-100. PubMed
  4. Murry JJ, Healy MD. Drug-mineral interactions: a new responsibility for the hospital dietician. J Am Diet Assoc 1991;91:66-73.
  5. Bailey DG, Dresser GK, Munoz C, et al. Reduction of fexofenadine bioavailability by fruit juices. Clin Pharmacol Ther 2001;69:P21.
  6. Pletz MW, Petzold P, Allen A, et al. Effect of calcium carbonate on bioavailability of orally administered gemifloxacin. Antimicrob Agents Chemother 2003;47:2158-60.. PubMed
  7. Lilja JJ, Juntti-Patinen L, Neuvonen PJ. Orange juice substantially reduces the bioavailability of the beta-adrenergic-blocking agent celiprolol. Clin Pharmacol Ther 2004;75:184-90.
  8. Tian R, Koyabu N, Takanaga H, et al. Effects of grapefruit juice and orange juice on the intestinal efflux of P-glycoprotein substrates. Pharm Res 2002;19:802-9. PubMed
  9. Vanapalli SR, Chen Y, Ellingrod VL, et al. Orange juice decreases the oral bioavailability of ivermectin in health volunteers. Clin Pharmacol Ther 2003;73 (Abstract PDII-A-10):P94.
  10. Huang SM, Lesko LJ. Drug-drug, drug-dietary supplement, and drug-citrus fruit and other food interactions: what have we learned? J Clin Pharmacol 2004;44:559-69. PubMed
  11. Koitabashi Y, Kumai T, Matsumoto N, et al. Orange juice increased the bioavailability of pravastatin, 3-hydroxy-3-methylglutaryl CoA reductase inhibitor, in rats and healthy human subjects. Life Sci 2006;78:2852-9. PubMed
  12. Takanaga H, Ohnishi A, Yamada S, et al. Polymethoxylated flavones in orange juice are inhibitors of P-glycoprotein but not cytochrome P450 3A4. J Pharmacol Exp Ther 2000;293:230-6. DOI
  13. Greenblatt DJ. Analysis of drug interactions involving fruit beverages and organic anion-transporting polypeptides. J Clin Pharmacol 2009;49:1403-7. PubMed
  14. Bailey DG. Fruit juice inhibition of uptake transport: a new type of food-drug interaction. Br J Clin Pharmacol 2010;70:645-55. PubMed
  15. Kamath AV, Yao M, Zhang Y, Chong S. Effect of fruit juices on the oral bioavailability of fexofenadine in rats. J Pharm Sci 2005;94:233-9. PubMed
  16. Kays MB, Overholser BR, Mueller BA, et al. Effects of sevelamer hydrochloride and calcium acetate on the oral bioavailability of ciprofloxacin. Am J Kidney Dis. 2003;42(6):1253-9. PubMed
  17. Neuhofel, A. L., Wilton, J. H., Victory, J. M., Hejmanowsk, L. G., and Amsden, G. W. Lack of bioequivalence of ciprofloxacin when administered with calcium-fortified orange juice: a new twist on an old interaction. J Clin Pharmacol. 2002;42(4):461-466. DOI

See these in context on the Sweet Orange 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

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