50 & Wiser Men Ingredients & Drug Interactions

Ginger may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs. However, research is conflicting.
Laboratory research suggests that ginger inhibits thromboxane synthetase and decreases platelet aggregation. However, this has not been demonstrated unequivocally in humans, with mixed results from clinical trials. Theoretically, excessive amounts of ginger might increase the risk of bleeding when used with anticoagulant/antiplatelet drugs.

Theoretically, taking ginger with antidiabetes drugs might increase the risk of hypoglycemia.
Animal and human research suggests that ginger might increase insulin levels and/or decrease blood glucose levels.

Ginger might increase or decrease the levels of CYP3A4 substrates.
In vitro research and some case reports suggest that ginger inhibits CYP3A4 activity. Three case reports from the World Health Organization (WHO) adverse drug reaction database describe increased toxicity in patients taking ginger and cancer medications that are CYP3A4 substrates (imatinib, dabrafenib, and crizotinib). However, the causality of this interaction is unclear due to the presence of multiple interacting drugs and routes of administration.
Conversely, other in vitro research suggests that ginger induces CYP3A4 activity, leading to reduced levels of CYP3A4 substrates. However, this interaction has not been reported in humans.

Theoretically, ginger might increase levels of losartan and the risk of hypotension.
In animal research, ginger increased the levels and hypotensive effects of a single dose of losartan. It is not clear if ginger alters the concentration or effects of losartan when taken continuously. Additionally, this interaction has not been shown in humans.

Ginger may have antiplatelet effects and increase the risk of bleeding if used with nifedipine.
Clinical research shows that combined treatment with ginger 1 gram plus nifedipine 10 mg significantly inhibits platelet aggregation when compared to nifedipine or ginger alone.

Ginger might increase the absorption and blood levels of P-glycoprotein (P-gp) substrates.
In vitro research and case reports suggest that ginger inhibits drug efflux by P-gp, potentially increasing absorption and serum levels of P-gp substrates. Two case reports from the World Health Organization (WHO) adverse drug reaction database describe increased toxicity in patients taking ginger and cancer medications that are P-gp substrates (trametinib, crizotinib). However, the causality of this interaction is unclear due to the presence of multiple interacting drugs and routes of administration.

Ginger might increase the risk of bleeding with phenprocoumon.
Phenprocoumon, a warfarin-related anticoagulant, might increase the international normalized ratio (INR) when taken with ginger. There is one case report of a 76-year-old woman with a stable INR on phenprocoumon that increased to greater than 10 when she began consuming dried ginger and ginger tea.

Ginger might increase the risk of bleeding with warfarin.
Laboratory research suggests that ginger might inhibit thromboxane synthetase and decrease platelet aggregation. In one case report, ginger increased the INR when taken with phenprocoumon, which has similar pharmacological effects as warfarin. In another case report, ginger increased the INR when taken with a combination of warfarin, hydrochlorothiazide, and acetaminophen. A longitudinal analysis suggests that taking ginger increases the risk of bleeding in patients taking warfarin for at least 4 months. However, research in healthy people suggests that ginger has no effect on INR, or the pharmacokinetics or pharmacodynamics of warfarin. Until more is known, monitor INRs closely in patients taking large amounts of ginger.

Theoretically, taking ginger with calcium channel blockers might increase the risk of hypotension.
Some animal and in vitro research suggests that ginger has hypotensive and calcium channel-blocking effects. Another animal study shows that concomitant administration of ginger and the calcium channel blocker amlodipine leads to greater reductions in blood pressure when compared with amlodipine alone.

Theoretically, when taken prior to cyclosporine, ginger might decrease cyclosporine levels.
In an animal model, ginger juice taken 2 hours prior to cyclosporine administration reduced the maximum concentration and area under the curve of cyclosporine by 51% and 40%, respectively. This effect was not observed when ginger juice and cyclosporine were administered at the same time.

Theoretically, ginger might increase the levels of CYP1A2 substrates.
In vitro research shows that ginger inhibits CYP1A2 activity. However, this interaction has not been reported in humans.

Theoretically, ginger might increase the levels of CYP2B6 substrates.
In vitro research shows that ginger inhibits CYP2B6 activity. However, this interaction has not been reported in humans.

Theoretically, ginger might increase the levels of CYP2C9 substrates.
In vitro research shows that ginger inhibits CYP2C9 activity. However, this interaction has not been reported in humans.

Theoretically, ginger might increase levels of metronidazole.
In an animal model, ginger increased the absorption and plasma half-life of metronidazole. In addition, the elimination rate and clearance of metronidazole was significantly reduced.

Garlic may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Raw garlic and a variety of garlic extracts have antiplatelet activity and can increase prothrombin time.

Theoretically, taking garlic with antidiabetes drugs might increase the risk of hypoglycemia.
Clinical research suggests that garlic and garlic extract lower blood glucose levels in healthy and diabetic individuals.

Theoretically, taking garlic with antihypertensive drugs might increase the risk of hypotension.
In human research, both garlic and garlic extracts have blood pressure-lowering effects.

Theoretically, garlic might decrease levels and effects of atazanavir.
In a case report, a patient consuming six stir-fried garlic cloves three times weekly developed suboptimal atazanavir levels and increases in HIV viral load. While the exact cause of this interaction is unclear, there is speculation that garlic might decrease the intestinal absorption of atazanavir or increase its metabolism by inducing cytochrome P450 3A4 (CYP3A4). Until more is known, advise patients not to consume large amounts of garlic while taking atazanavir.

Garlic might increase levels of drugs metabolized by CYP2E1.
Clinical research suggests garlic oil can inhibit the activity of CYP2E1 by 39%. Use garlic oil cautiously in patients taking drugs metabolized by these enzymes.

Theoretically, garlic products containing allicin might induce intestinal CYP3A4 and inhibit hepatic CYP3A4. This may increase or decrease levels of drugs metabolized by CYP3A4.
Some human research suggests that garlic may induce INTESTINAL CYP3A4, reducing levels of drugs metabolized by this enzyme. This is primarily based on a study showing that taking a specific allicin-containing garlic product (GarliPure Maximum Allicin Formula, Natrol Inc.) twice daily for 3 days reduces saquinavir levels by approximately 50%. It is speculated that the allicin constituent induced CYP3A4 in the gut mucosa. Another study shows that giving docetaxel intravenously, bypassing the CYP3A4 enzymes in the gut mucosa, along with the same specific garlic product for 12 consecutive days, does not affect docetaxel levels. Conversely, there is concern that garlic may inhibit HEPATIC CYP3A4. In a single case report, increased tacrolimus levels and liver injury occurred in a liver transplant patient after taking a specific garlic supplement (Garlicin Cardio, Nature's Way) at up to three times the manufacturer recommended dose for 7 days. Several other studies have evaluated the impact of other garlic formulations on CYP3A4 substrates and have found no effect. Most of the products in these studies provided little or no allicin.

Theoretically, garlic might decrease levels of isoniazid.
Animal research suggests that an aqueous extract of garlic reduces isoniazid levels by about 65%. Garlic reduced the maximum concentration (Cmax) and area under the curve (AUC), but not the half-life, of isoniazid. This suggests that garlic extract might inhibit isoniazid absorption across the intestinal mucosa; however, the exact mechanism of this potential interaction is not known.

Theoretically, garlic products containing allicin might decrease levels of PIs.
Protease inhibitors are metabolized by cytochrome P450 3A4 (CYP3A4) isoenzymes. There is concern that garlic products containing allicin might induce intestinal CYP3A4, reducing plasma levels of protease inhibitors. This is primarily based on a study showing that taking a specific garlic product (GarliPure Maximum Allicin Formula, Natrol Inc.) twice daily for 3 days reduces levels of saquinavir, a PI, by approximately 50%. It is speculated that the allicin constituent induce CYP3A4 in the gut mucosa. Several studies have evaluated the impact of other garlic formulations on CYP3A4 substrates and have found no effect. Most of the products in these studies provided little or no allicin.

Theoretically, garlic containing allicin might decrease levels of saquinavir.
Saquinavir is a substrate of cytochrome P450 3A4 (CYP3A4) isoenzymes. There is concern that garlic products containing allicin might induce intestinal CYP3A4 and cause subtherapeutic levels of saquinavir. This is primarily based on a pharmacokinetic study showing that taking a specific garlic product (GarliPure Maximum Allicin Formula, Natrol Inc.) twice daily for 3 days reduces saquinavir levels by approximately 50%. It is speculated that the allicin constituent induces CYP3A4 in the gut mucosa. Several pharmacokinetic studies have evaluated the impact of other garlic formulations on CYP3A4 substrates and have found no effect. Most of the products in these studies provided little or no allicin. Until more is known about this potential interaction, use garlic containing allicin cautiously in patients taking saquinavir.

Theoretically, taking garlic with sofosbuvir might decrease its effectiveness.
Animal research in rats shows that giving aged garlic extract 120 mg/kg orally daily for 14 days decreases the area under the concentration time curve (AUC) after a single sofosbuvir dose of 40 mg/kg by 36%, increases the clearance by 63%, and decreases the plasma concentrations at 1 and 8 hours by 35% and 58%, respectively. This interaction is hypothesized to be due to induction of intestinal P-glycoprotein expression by garlic.

Theoretically, garlic might increase levels of tacrolimus.
In one case report, a liver transplant patient taking tacrolimus experienced increased tacrolimus levels and liver injury after taking a specific garlic supplement (Garlicin Cardio, Nature's Way) at up to three times the manufacturer recommended dose for 7 days. It is speculated that garlic inhibited hepatic cytochrome P450 3A4 (CYP3A4), which increased plasma levels of tacrolimus.

Theoretically, garlic might increase the risk of bleeding with warfarin.
Raw garlic and a variety of garlic extracts have antiplatelet activity and can increase prothrombin time. In addition, there is a report of two patients who experienced an increase in a previously stabilized international normalized ratio (INR) with concomitant garlic and warfarin use. However, this report has been subsequently debated due to limited clinical information. Other clinical studies have not identified an effect of garlic on INR, warfarin pharmacokinetics, or bleeding risk. More evidence is needed to determine the safety of using garlic with warfarin.

Theoretically, beet might increase the levels of CYP3A4 substrates.
In vitro research suggests that betanin, the major pigment in beet, competitively inhibits CYP3A4 in a dose-dependent manner similarly to strong CYP3A4 inhibitor ketoconazole.

Beet and beetroot contain nitrates, which can cause vasodilation, potentially leading to lower blood pressure. However, a study published in the European Journal of Clinical Nutrition using concentrated beetroot juice found no significant impact on blood pressure or heart rate in different age groups. Other small clinical studies suggest that while beet consumption might transiently lower blood pressure due to vessel dilation, there's no consistent evidence of a lasting effect. Overall, the theoretical risk of reduced blood pressure due to beet's nitrate content exists, but studies generally indicate a low and temporary impact rather than a sustained decrease.

Theoretically, beet might decrease the levels and clinical effects of CYP1A2 substrates.
In vitro research suggests that beet induces CYP1A2 enzymes.

Theoretically, antioxidant effects of vitamin E might reduce the effectiveness of alkylating agents.
There's concern that antioxidants could reduce the activity of chemotherapy drugs which generate free radicals, such as cyclophosphamide, chlorambucil, carmustine, busulfan, and thiotepa. However, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that might interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effect, if any, antioxidants such as vitamin E have on chemotherapy. Advise patients to consult their oncologist before using vitamin E supplements, especially in high doses.

Concomitant use of vitamin E and anticoagulant or antiplatelet agents might increase the risk of bleeding.
Vitamin E seems to inhibit of platelet aggregation and antagonize the effects of vitamin K-dependent clotting factors. These effects appear to be dose-dependent, and are probably only likely to be clinically significant with doses of at least 800 units daily. Mixed tocopherols, such as those found in food, might have a greater antiplatelet effect than alpha-tocopherol. RRR alpha-tocopherol (natural vitamin E) 1000 IU daily antagonizes vitamin K-dependent clotting factors. Advise patients to avoid high doses of vitamin E, especially in people with low vitamin K intake or other risk factors for bleeding.

Theoretically, antioxidant effects of vitamin E might reduce the effectiveness of antitumor antibiotics.
There's concern that antioxidants could reduce the activity of antitumor antibiotic drugs such as doxorubicin, which generate free radicals. However, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that might interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effect, if any, antioxidants such as vitamin E have on chemotherapy involving antitumor antibiotics. Advise patients to consult their oncologist before using vitamin E supplements, especially in high doses.

A specific form of vitamin E might increase absorption and levels of cyclosporine.
There is some evidence that one specific formulation of vitamin E (D-alpha-tocopheryl-polyethylene glycol-1000 succinate, TPGS, tocophersolan, Liqui-E) might increase absorption of cyclosporine. This vitamin E formulation forms micelles which seems to increase absorption of cyclosporine by 40% to 72% in some patients. However, this interaction is unlikely to occur with the usual forms of vitamin E.

Theoretically, vitamin E might induce metabolism of CYP3A4, possibly reducing the levels CYP3A4 substrates.
Vitamin E appears to bind with the nuclear receptor, pregnane X receptor (PXR), which results in increased expression of CYP3A4. Although the clinical significance of this is not known, use caution when considering concomitant use of vitamin E and other drugs affected by these enzymes.

Taking selumetinib with vitamin E can result in a total daily dose of vitamin E that exceeds safe limits and therefore might increase the risk of bleeding.
Selumetinib contains 48-54 IU vitamin E per capsule. The increased risk of bleeding with vitamin E appears to be dose-dependent. Be cautious when using selumetinib in combination with supplemental vitamin E, especially in patients at higher risk of bleed, such as those with chronic conditions and those taking antiplatelet drugs.

Using vitamin E with warfarin might increase the risk of bleeding.
Due to interference with production of vitamin K-dependent clotting factors, use of more than 400 IU of vitamin E daily with warfarin might increase prothrombin time (PT), INR, and the risk of bleeding,. At a dose of 1000 IU per day, vitamin E can antagonize vitamin K-dependent clotting factors even in people not taking warfarin. Limited clinical evidence suggests that doses up to 1200 IU daily may be used safely by patients taking warfarin, but this may not be applicable in all patient populations.

Vitamin E might decrease the beneficial effects of niacin on high-density lipoprotein (HDL) cholesterol levels.
A combination of niacin and simvastatin (Zocor) effectively raises high-density lipoprotein (HDL) cholesterol levels in people 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%. Vitamin E alone combined with a statin does not seem to decrease HDL levels. It is not known whether the adverse effect on HDL is due to one of the other antioxidants or to the combination. It also is not known whether it will occur in other patient populations.

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.

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.

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.

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.

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.

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.

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.

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.

Theoretically, celery root might increase the risk of bleeding when taken with anticoagulant/antiplatelet drugs.
Celery root contains the constituents falcarinol and falcarindiol. Laboratory research suggests that these constituents can inhibit platelet aggregation. This effect has not been reported in humans.

Theoretically, celery seed extract might have additive effects with antihypertensive drugs.
Clinical research suggests that taking celery seed extract may reduce daytime systolic blood pressure by about 12 mmHg compared to less than 1 mmHg with placebo.

Theoretically, celery might increase levels of drugs metabolized by CYP1A2.
In vitro and animal research suggests that constituents of celery can inhibit CYP1A2. This effect has not been reported in humans.

Theoretically, celery seed might decrease the effects of levothyroxine.
Several cases of hypothyroidism with low T4 levels have been reported in people who were previously stabilized on levothyroxine and then started taking celery seed tablets. They presented with symptoms such as lethargy, bloating, and dry skin, and recovered when celery seed was stopped. However, celery stem and leaf has been associated with case reports of hyperthyroidism in patients with no pre-existing thyroid disorders.

Theoretically, celery might reduce excretion and increase levels of lithium due to potential diuretic effects.
Celery is thought to have diuretic properties. However, this effect has not been confirmed in humans.

Theoretically, celery root extract might increase blood levels of venlafaxine.
There is one case report of a patient who experienced medication-induced bipolar disorder after beginning to take celery root extract 1000 mg daily along with venlafaxine 75 mg and St. John's wort 600 mg daily. Symptoms included confusion, speech abnormalities, manic affect, and visual hallucinations. The plasma level of venlafaxine was 476.8 ng/mL (normal range 195-400 ng/mL). It is theorized that celery root increased venlafaxine levels by inhibiting cytochrome P450 2D6.

Theoretically, celery juice might increase the effects and side effects of acetaminophen.
Animal research suggests that concomitant use of celery juice plus acetaminophen prolongs the effects of acetaminophen. This effect has been attributed to a decrease in hepatic cytochrome P450 activity. However, other animal research shows that pretreatment with celery root extract protects against acetaminophen-induced acute liver failure. These effects have not been reported in humans.

Theoretically, celery might increase the risk of photosensitivity reactions when taken with photosensitizing drugs.
Laboratory research shows that celery contains photosensitizing agents such as phenols and psoralens.

Theoretically, parsley might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.
Animal research suggests that parsley has antiplatelet effects.

Theoretically, parsley might increase the risk of hypoglycemia when taken with antidiabetes drugs.
Animal research suggests that parsley might decrease blood glucose. Monitor blood glucose levels closely. Dose adjustments might be necessary.

Theoretically, parsley might increase serum levels of CYP1A2 substrates.
Laboratory research suggests that parsley can inhibit CYP1A2.

Theoretically, parsley might enhance or interfere with the effects of diuretic drugs.
Animal research suggests that parsley seed extract increases urine elimination. Parsley leaf and root might also interfere with diuretic therapy due their purported aquaretic effects.

Theoretically, parsley might increase the duration of pentobarbital effects.
Animal research suggests that parsley juice prolongs the action of pentobarbital, perhaps by decreasing cytochrome P450 levels. It is not known if this occurs in humans or if this applies to other barbiturates or sedatives.

Theoretically, large quantities of parsley might increase sirolimus levels.
In one case report, an adult female with a history of kidney transplant presented with elevated blood sirolimus levels, approximately 4-7 times greater than previous measures, after daily consumption of a juice containing approximately 30 grams of parsley for 7 days. Sirolimus levels returned to normal a week after the parsley juice was discontinued.

Theoretically, large amounts of parsley leaf and root might decrease the effects of warfarin.
Parlsey contains vitamin K.

Theoretically, aspirin might increase the severity of allergic reactions to parsley.
In one case, severe urticaria and swelling were reported after taking aspirin with parsley in an individual with a known mild parsley allergy.

Concomitant use of retinoids with vitamin A supplements might produce supratherapeutic vitamin A levels.
Retinoids, which are vitamin A derivatives, could have additive toxic effects when taken with vitamin A supplements.

Theoretically, taking high doses of vitamin A in combination with other potentially hepatotoxic drugs might increase the risk of liver disease.
The tolerable upper intake level (UL) is the highest level of intake that is likely to pose no risk of adverse effects. Doses of vitamin A above the UL can cause hepatotoxicity, ranging from elevated liver enzymes to liver failure.

Theoretically, taking tetracycline antibiotics with high doses of vitamin A can increase the risk of pseudotumor cerebri.
Benign intracranial hypertension (pseudotumor cerebri) can occur with tetracyclines and with acute or chronic vitamin A toxicity. Case reports suggest that taking tetracyclines and vitamin A concurrently can increase the risk of this condition. Avoid high doses of vitamin A in people taking tetracyclines chronically.

Theoretically, high doses of vitamin A could increase the risk of bleeding with warfarin.
Vitamin A toxicity is associated with hemorrhage and hypoprothrombinemia, possibly due to vitamin K antagonism. Advise patients taking warfarin to avoid doses of vitamin A above the tolerable upper intake level of 10,000 IU/day for adults.

Cabbage might increase clearance and reduce the effects of acetaminophen.
A small clinical study shows that daily consumption of cabbage and Brussels sprout decreases acetaminophen levels by as much as 16%, with some evidence suggesting that this effect is due to increased elimination through glucuronide conjugation.

Theoretically, cabbage might increase the risk of hypoglycemia when taken with antidiabetes drugs.
Animal and in vivo research suggests that cabbage might have hypoglycemic effects.

Theoretically, cabbage might decrease levels of drugs metabolized by CYP1A2.
Some animal research suggests that cabbage or its constituent indole-3-carbinol might increase drug metabolism and elimination by stimulating CYP1A2 activity.

Theoretically, cabbage might increase clearance and decrease the effects of drugs metabolized through glucuronide conjugation.
A small clinical study shows that daily consumption of cabbage and Brussels sprout decreases levels of some drugs metabolized through glucuronide conjugation.

Cabbage might increase clearance and reduce the effects of oxazepam.
A small clinical study shows that daily consumption of cabbage and brussels sprout decreases oxazepam levels by as much as 17%, with some evidence suggesting that this effect is due to increased elimination through glucuronide conjugation.

Theoretically, cabbage might decrease the anticoagulant effects of warfarin.
Cabbage contains vitamin K. If consumed in large quantities, cabbage might decrease the anticoagulant effects of warfarin.

Selenium may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Clinical research suggests that taking selenium 10 mcg/kg/day can increase bleeding times by increasing prostacyclin production, which inhibits platelet activity. Other clinical research suggests that taking selenium 75 mcg daily, in combination with ascorbic acid 600 mg, alpha-tocopherol 300 mg, and beta-carotene 27 mg, reduces platelet aggregation.

Theoretically, selenium might prolong the sedating effects of barbiturates.
Laboratory research suggests that selenium can inhibit the hepatic metabolism of barbiturates. Selenium seems to prolong the sedative effect of pentobarbital in animal models.

Theoretically, selenium supplementation may reduce the effectiveness of immunosuppressant therapy.
In vitro research and preliminary clinical evidence suggests that selenium may stimulate the immune system.

Theoretically, selenium might interfere with warfarin activity.
Animal research suggests that selenium can increase warfarin activity. Selenium might interact with warfarin by displacing it from albumin binding sites, reducing its metabolism in the liver, or by decreasing production of vitamin K-dependent clotting factors. Selenium can also prolong bleeding times in humans by increasing prostacyclin production, which inhibits platelet activity.

Contraceptive drugs might increase levels of selenium, although the clinical significance of this effect is unclear.
Some research suggests that oral contraceptives increase serum selenium levels in women taking oral contraceptives; however, other research shows no change in selenium levels. It is suggested that an increase could be due to increased carrier proteins, indicating a redistribution of selenium rather than a change in total body selenium.

Selenium might reduce the beneficial effects of niacin on high-density lipoprotein (HDL) 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 selenium, or to the combination. It also is not known whether it will occur in other patient populations.

In vitro and animal research suggests that strawberry extract can inhibit platelet aggregation due to its phenolic content. Theoretically, strawberry might increase the risk of bleeding when used with antiplatelet or anticoagulant drugs.
Some anticoagulant or antiplatelet drugs include aspirin, clopidogrel (Plavix), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, ticlopidine (Ticlid), warfarin (Coumadin), and others.

In vitro research suggests that strawberry extract can inhibit p-glycoprotein efflux. Theoretically, strawberry might inhibit p-glycoprotein mediated drug efflux and potentially increase levels of drugs that are substrates of p-glycoprotein. Until more is known, strawberry should be used cautiously in people taking p-glycoprotein substrates.
Drugs that might be affected include some chemotherapeutic agents (etoposide, paclitaxel, vinblastine, vincristine, vindesine), antifungals (ketoconazole, itraconazole), protease inhibitors (amprenavir, indinavir, nelfinavir, saquinavir), H2 antagonists (cimetidine, ranitidine), some calcium channel blockers (diltiazem, verapamil), corticosteroids, erythromycin, cisapride (Propulsid), fexofenadine (Allegra), cyclosporine, loperamide (Imodium), quinidine, and others.

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.

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.

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.

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.

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.

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.

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.

Theoretically, concomitant use of anticoagulant or antiplatelet drugs with onion might increase the risk of bleeding.
In vitro research shows that onion inhibits platelet aggregation.

Concomitant use of antidiabetes drugs with onion may increase the risk of hypoglycemia.
Animal research and clinical research shows that taking onion can lower blood glucose levels. Monitor blood glucose levels closely.

Concomitant use of aspirin with onion may worsen onion allergy.
In one case report, a patient with a mild onion allergy reported worsening allergy, including swelling and severe urticaria, after taking aspirin.

Theoretically, taking onion might increase the levels and clinical effects of drugs metabolized by CYP2E1.
Animal research shows that taking onion powder inhibits CYP2E1. However, this interaction has not been reported in humans.

Onion is thought to have diuretic properties. Theoretically, due to these potential diuretic effects, onion might reduce excretion and increase levels of lithium. The dose of lithium might need to be decreased.

Theoretically, capsicum may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
In vitro research shows that capsicum might increase the effects of antiplatelet drugs. Also, population research shows that capsicum is associated with an increased risk of self-reported bleeding in patients taking warfarin. However, clinical research shows that taking a single dose of capsaicin (Asian Herbex Ltd.), the active ingredient in capsicum, 400-800 mcg orally in combination with aspirin 500 mg does not decrease platelet aggregation when compared with taking aspirin 500 mg alone. Also, there was no notable effect on measures of platelet aggregation with capsaicin. It is unclear whether capsaicin must be used in more than a single dose to affect platelet aggregation.

Theoretically, taking capsicum with antidiabetes drugs might increase the risk of hypoglycemia.
Preliminary clinical research shows that consuming capsicum 5 grams along with a glucose drink attenuates the rise in plasma glucose after 30 minutes by 21%, decreases the 2-hour postprandial area under the curve of plasma glucose by 11%, and increases the 2-hour postprandial area under the curve of plasma insulin by 58% in healthy individuals when compared with placebo. Other clinical research shows that taking capsicum 5 mg daily for 28 days significantly reduces postprandial blood glucose and insulin levels, but not fasting blood glucose and insulin levels, in patients with gestational diabetes.

Theoretically, taking capsicum with aspirin might reduce the bioavailability of aspirin.
Animal research shows that acute or chronic intake of capsicum pepper reduces oral aspirin bioavailability. This has not been shown in humans.

Theoretically, taking capsicum with theophylline might increase the levels and adverse effects of theophylline.
In animal research, oral administration of capsicum reduced excretion of theophylline. However, capsicum does not seem to affect the pharmacokinetics of theophylline when administered intravenously.

Theoretically, using topical capsaicin may increase the risk of ACE inhibitor-induced cough.
There is one case report of a topically applied capsaicin cream contributing to the cough reflex in a patient using an ACEI. However, it is unclear if this interaction is clinically significant.

Theoretically, taking capsicum with ciprofloxacin might increase levels and adverse effects of ciprofloxacin.
Animal research shows that concomitant use of capsaicin, the active constituent of capsicum, and ciprofloxacin increases the bioavailability of ciprofloxacin by up to 70%.

Theoretically, vitamin B6 might increase the photosensitivity caused by amiodarone.
Despite initial case reports suggesting that pyridoxine may have a protective effect against amiodarone-induced photosensitivity, preliminary clinical research suggests that pyridoxine may actually exacerbate this adverse effect.

Theoretically, vitamin B6 may have additive effects when used with antihypertensive drugs.
Research in hypertensive rats shows that vitamin B6 can decrease systolic blood pressure. Similarly, clinical research in patients with hypertension shows that taking high doses of vitamin B6 may reduce systolic and diastolic blood pressure, possibly by reducing plasma levels of epinephrine and norepinephrine.

High doses of vitamin B6 may reduce the levels and clinical effects of phenobarbital.
Preliminary clinical evidence suggests that vitamin B6 200 mg daily can reduce plasma levels of phenobarbital, possibly by increasing metabolism. It is not known whether lower doses have any effect. Advise people taking phenobarbital to avoid high doses of vitamin B6.

High doses of vitamin B6 may reduce the levels and clinical effects of phenytoin.
Preliminary clinical evidence suggests that vitamin B6 200 mg daily can reduce plasma levels of phenytoin, possibly by increasing metabolism. It is not known whether lower doses have any effect. Advise people taking phenytoin to avoid high doses of vitamin B6.

Vitamin B6 may increase the metabolism of levodopa when taken alone, but not when taken in conjunction with carbidopa.
Vitamin B6 (pyridoxine) enhances the metabolism of levodopa, reducing its clinical effects. However, this interaction does not occur when carbidopa is used concurrently with levodopa (Sinemet). Therefore, it is not likely to be a problem in most people.

Theoretically, vanadium might increase the risk of bleeding when taken with anticoagulant/antiplatelet drugs.
In vitro research shows that the sodium orthovanadate form of vanadium prolongs clotting time, likely through inhibition of thrombin and factor Xa.

Theoretically, vanadium might increase the risk of hypoglycemia when taken with antidiabetes drugs.
A few very small clinical studies in patients with type 2 diabetes show that the vanadyl sulfate form of vanadium increases insulin sensitivity and might lower blood glucose levels.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Coenzyme Q10 has antioxidant effects. Theoretically, this may reduce the activity of chemotherapy drugs that generate free radicals.
Theoretically, antioxidants such as coenzyme Q10 might protect tumor cells from chemotherapeutic agents that work by inducing oxidative stress, such as alkylating agents (e.g., cyclophosphamide) and radiation therapy. The clinical importance of this interaction is unknown.

Coenzyme Q10 is chemically similar to menaquinone and might have vitamin K-like procoagulant effects, which could decrease the effects of warfarin.
Concomitant use of coenzyme Q10 and warfarin might reduce the anticoagulant effects of warfarin. Four cases of decreased warfarin efficacy thought to be due to coenzyme Q10 have been reported. However, there is some preliminary clinical research that suggests coenzyme Q10 might not significantly decrease the effects of warfarin in patients who have a stable INR.

Theoretically, coenzyme Q10 might have additive effects with antihypertensive drugs.
Some clinical research shows that coenzyme Q10 can significantly lower blood pressure, although other studies have shown conflicting results.

Theoretically, broccoli might reduce the levels and effects of drugs metabolized by CYP1A2.
Pharmacokinetic research in humans shows that eating 500 grams of fresh broccoli daily for 6-12 days can increase CYP1A2 activity by 10% to 200%. Induction of CYP1A2 activity by broccoli is attributed to its glucosinolate constituents.

Theoretically, broccoli might reduce the levels and effects of drugs metabolized by CYP2A6.
Pharmacokinetic research in humans shows that eating 500 grams of broccoli daily for 6 days increases CYP2A6 activity by 135% to 550%. Induction of CYP2A6 activity is attributed to its glucosinolate constituents.

Preliminary clinical evidence suggests that eating cruciferous vegetables, including broccoli, cauliflower, daikon radish sprouts, and cabbage, can increase cytochrome P450 1A2 (CYP1A2) activity by 14% to 27%. Theoretically, cauliflower might increase the clearance and decrease the effects of drugs metabolized by CYP1A2. Some drugs metabolized by CYP1A2 include clozapine (Clozaril), cyclobenzaprine (Flexeril), fluvoxamine (Luvox), haloperidol (Haldol), imipramine (Tofranil), mexiletine (Mexitil), olanzapine (Zyprexa), pentazocine (Talwin), propranolol (Inderal), tacrine (Cognex), theophylline, zileuton (Zyflo), zolmitriptan (Zomig), and others.

Theoretically, chromium may have additive effects with antidiabetic agents and increase the risk of hypoglycemia.
Some research shows that taking chromium might lower blood glucose levels, especially in patients with poorly controlled type 2 diabetes.

Theoretically, concomitant use of chromium and insulin might increase the risk of hypoglycemia.
In clinical research, chromium has been shown to increase insulin sensitivity,

Chromium might bind levothyroxine in the intestinal tract and decrease levothyroxine absorption.
Clinical research in healthy volunteers shows that taking chromium picolinate 1000 mcg with levothyroxine 1 mg decreases serum levels of levothyroxine by 17% when compared to taking levothyroxine alone. Advise patients to take levothyroxine at least 30 minutes before or 3-4 hours after taking chromium.

Theoretically, aspirin might increase chromium absorption.
Animal research suggests that aspirin may increase chromium absorption and chromium levels in the blood.

NSAIDs might increase chromium levels in the body.
Drugs that are prostaglandin inhibitors, such as NSAIDs, seem to increase chromium absorption and retention.

Bromelain may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
There is one case report of a patient experiencing minor bruising while taking bromelain with naproxen. Bromelain is thought to have antiplatelet activity. Whether this interaction is of concern with topical bromelain is unclear. Interference with coagulation of burn wounds has been reported in a patient receiving bromelain-based enzymatic debridement. However, observational research has found that topical bromelain debridement is not associated with increases or decreases in laboratory markers of coagulation when compared with surgical debridement.

Theoretically, bromelain might increase levels of tetracycline antibiotics.
Laboratory research suggests that bromelain might increase the absorption of tetracycline antibiotics. However, a study in healthy adults reported no difference in tetracycline plasma levels when a 500 mg dose was taken with or without bromelain 80 mg.

Theoretically, niacinamide may have additive effects when used with anticoagulant or antiplatelet drugs, especially in patients on hemodialysis.
Several cases of thrombocytopenia have been reported for hemodialysis patients treated with niacinamide 1 gram daily. Hemodialysis patients receiving niacinamide had almost a three-fold higher risk of developing thrombocytopenia when compared with those receiving placebo.

Niacinamide might increase the levels and adverse effects of carbamazepine.
Plasma levels of carbamazepine were increased in two children given high-dose niacinamide, 60-80 mg/kg/day. This might be due to inhibition of the cytochrome P450 enzymes involved in carbamazepine metabolism. There is not enough data to determine the clinical significance of this interaction.

Niacinamide might increase the levels and adverse effects of primidone.
Case reports in children suggest niacinamide 60-100 mg/kg/day reduces hepatic metabolism of primidone to phenobarbital, and reduces the overall clearance rate of primidone; however, there is not enough data to determine the clinical significance of this potential interaction.

There is limited evidence that niacinamide may increase the anticoagulant effects of warfarin.
In a case report, a patient on warfarin developed an elevated international normalized ratio (INR) of 8.4 after taking niacinamide 500 mg twice daily for 10 days. The patient's INR was previously stable, ranging between 2 and 3, with no other changes to current medications or diet reported. The elevated INR returned to the therapeutic range after receiving vitamin K and discontinuing niacinamide.

Theoretically, taking lycopene with anticoagulant or antiplatelet drugs might increase the risk of bleeding.
In vitro research shows that lycopene has antiplatelet effects.

There are claims that spinach leaves have hypoglycemic effects. Evidence from clinical research suggests that consumption of a spinach-rich meal reduces post-meal blood glucose levels. Theoretically, spinach might have additive effects with antidiabetes drugs and increase the risk of hypoglycemia. Monitor blood glucose levels closely. Dose adjustments might be necessary. Some antidiabetes drugs include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, pioglitazone (Actos), rosiglitazone (Avandia), and others.

Spinach contains vitamin K, which can interfere with the activity of warfarin.
In human research, although eating spinach with one meal does not result in coagulation test results outside the therapeutic range, daily consumption for one week necessitates dose adjustment of warfarin. Individuals using anticoagulants should consume a consistent daily amount of spinach to maintain the effect of anticoagulant therapy.

Theoretically, blueberries or blueberry leaf extracts might increase the risk of hypoglycemia when taken with antidiabetes drugs.
Animal and in vitro research suggests that blueberry and/or blueberry leaf extracts can lower blood glucose levels.

Theoretically, blueberry juice might increase blood levels of buspirone.
In vitro research shows that blueberry juice can inhibit the metabolism of buspirone, possibly by inhibiting cytochrome P450 3A (CYP3A) enzymes. However, pharmacokinetic research in humans shows that drinking 300 mL of blueberry juice 30 minutes before taking buspirone hydrochloride 10 mg does not significantly affect the concentration or clearance of buspirone.

Theoretically, blueberry juice might increase blood levels of flurbiprofen.
In vitro research shows that blueberry juice can inhibit the metabolism of flurbiprofen, possibly by inhibiting cytochrome P450 2C9 (CYP2C9) enzymes. However, pharmacokinetic research in humans shows that drinking 300 mL of blueberry juice 30 minutes before taking flurbiprofen 100 mg does not significantly affect the concentration or clearance of flurbiprofen.

Theoretically, cucumber seed might have additive effects with antidiabetes drugs and may increase the risk of hypoglycemia.
Animal research shows that cucumber seed extract can decrease blood glucose levels. Monitor blood glucose levels closely.

Theoretically, the risk for manganese toxicity might increase when taken with antipsychotic drugs.
Hallucinations and behavioral changes have been reported in a patient with liver disease who was taking haloperidol and manganese. Researchers speculate that taking manganese along with haloperidol, phenothiazine-derivatives, or other antipsychotic medications might increase the risk of manganese toxicity in some patients.

Theoretically, manganese might reduce the absorption of quinolone antibiotics.
Manganese is a multivalent cation. Interactions resulting in reduced quinolone absorption have been reported between quinolones and other multivalent cations, such as calcium and iron.

Theoretically, manganese might reduce the absorption of tetracycline antibiotics.
Manganese is a multivalent cation. Interactions resulting in reduced tetracycline absorption have been reported between tetracyclines and other multivalent cations, such as calcium and iron.

Theoretically, asparagus root might increase diuresis and electrolyte loss when used with diuretic drugs.
Animal studies show that asparagus root extracts have diuretic effects. This effect has not been reported in humans.

Theoretically, asparagus root might cause diuresis, reducing lithium clearance.
Animal studies show that asparagus root extracts have diuretic effects. Theoretically, this might reduce excretion and increase levels of lithium. The dose of lithium might need to be decreased.

Theoretically, zinc 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 zinc containing products.

Zinc might decrease cephalexin levels by chelating with cephalexin in the gut and preventing its absorption.
A pharmacokinetic study shows that zinc sulfate 250 mg taken concomitantly with cephalexin 500 mg decreases peak levels of cephalexin by 31% and reduces the exposure to cephalexin by 27%. Also, taking zinc sulfate 3 hours before cephalexin decreases peak levels of cephalexin by 11% and reduces the exposure to cephalexin by 18%. By decreasing cephalexin levels, zinc might increase the risk of treatment failure. This effect does not occur when zinc is taken 3 hours after the cephalexin dose. To avoid an interaction, advise patients take zinc sulfate 3 hours after taking cephalexin.

Theoretically, zinc might interfere with the therapeutic effects of cisplatin.
Animal research suggests that zinc stimulates tumor cell production of the protein metallothionein, which binds and inactivates cisplatin. It is not known whether zinc supplements or high dietary zinc intake can cause clinically significant interference with cisplatin therapy. Cisplatin might also increase zinc excretion.

Theoretically, taking zinc along with integrase inhibitors might decrease the levels and clinical effects of these drugs.
Zinc is a divalent cation. Pharmacokinetic studies have shown that other divalent cations such as calcium and iron can decrease blood levels of the integrase inhibitor dolutegravir through chelation.

Zinc might reduce the levels and clinical effects of penicillamine.
By forming an insoluble complex with penicillamine, zinc interferes with penicillamine absorption and activity. Zinc supplements reduce the efficacy of low-dose penicillamine (0.5-1 gram/day), but do not seem to affect higher doses (1-2.75 gram/day), provided dosing times are separated. Advise patients to take zinc and penicillamine at least 2 hours apart.

Zinc can decrease the levels and clinical effects of quinolones antibiotics.
Quinolones form complexes with zinc in the gastrointestinal tract, reducing absorption of both the quinolone and zinc if taken at the same time. Advise patients to take these drugs at least 2 hours before, or 4-6 hours after, zinc supplements.

Zinc modestly reduces levels of ritonavir.
Clinical research shows that zinc might reduce serum ritonavir levels by chelating with ritonavir in the gut and preventing its absorption. In patients with HIV, ritonavir is taken with atazanavir to prevent the metabolism and increase the effects of atazanavir. A pharmacokinetic study shows that, in patients being treated with atazanavir/ritonavir, co-administration of zinc sulfate (Solvazinc tablets) 125 mg as a single dose or as multiple daily doses for 2 weeks reduces plasma levels of ritonavir by about 16%. However, atazanavir levels still remains high enough to prevent HIV virus replication. Therefore, the decrease in ritonavir levels is not likely to be clinically significant.

Zinc might reduce levels of tetracycline antibiotics.
Tetracyclines form complexes with zinc in the gastrointestinal tract, which can reduce absorption of both the tetracycline and zinc when taken at the same time. Taking zinc sulfate 200 mg with tetracycline reduces absorption of the antibiotic by 30% to 40%. Demeclocycline and minocycline cause a similar interaction. However, doxycycline does not seem to interact significantly with zinc. Advise patients to take tetracyclines at least 2 hours before, or 4-6 hours after, zinc supplements to avoid any interactions.

Amiloride can modestly reduce zinc excretion and increase zinc levels.
Clinical research shows that amiloride can reduce urinary zinc excretion, especially at doses of 10 mg per day or more. This zinc-sparing effect can help to counteract zinc losses caused by thiazide diuretics, but it is unlikely to cause zinc toxicity at usual amiloride doses. The other potassium-sparing diuretics, spironolactone (Aldactone) and triamterene (Dyrenium), do not seem to have a zinc-sparing effect.

Zinc modestly reduces levels of atazanavir, although this effect does not seem to be clinically significant.
Clinical research shows that zinc might decrease serum atazanavir levels by chelating with atazanavir in the gut and preventing its absorption. Although a single dose of zinc sulfate (Solvazinc tablets) 125 mg orally does not affect atazanavir concentrations in patients being treated with atazanavir/ritonavir, co-administration of zinc sulfate 125 mg daily for 2 weeks reduces plasma levels of atazanavir by about 22% in these patients. However, despite this decrease, atazanavir levels still remain at high enough concentrations for the prevention of HIV virus replication.

Theoretically, taking riboflavin with tetracycline antibiotics may decrease the potency of these antibiotics.
In vitro research suggests that riboflavin may inhibit the potency of tetracycline antibiotics. It is not clear if this effect is clinically significant, as this interaction has not been reported in humans.

Metformin, a common medication used to manage type 2 diabetes, has been associated with lower vitamin B12 levels in some individuals. Prolonged use of metformin can interfere with the absorption of B12 in the digestive system, potentially leading to a deficiency in this essential vitamin.

Combining iodine with amiodarone might cause excessively high iodine levels.
Amiodarone contains 37.3% iodine and can increase iodine levels. Concomitant use with iodine might increase the risk of having excessive iodine levels and adversely affecting thyroid function. Monitor thyroid function.

Iodine might alter the effects of antithyroid drugs.
Iodine in high doses has been reported to cause both hyperthyroidism and hypothyroidism, depending on the individual's past medical history. Taking iodine while using antithyroid drugs could alter the effects of the antithyroid drugs.

Combining iodine with lithium might have additive hypothyroid effects.
Lithium can inhibit thyroid function. Several case reports suggest that concomitant use of lithium and potassium iodide can reduce thyroid function in otherwise healthy adults. Monitor thyroid function.

Trimethoprim might increase blood levels of thiamine.
In vitro, animal, and clinical research suggest that trimethoprim inhibits intestinal thiamine transporter ThTR-2, hepatic transporter OCT1, and renal transporters OCT2, MATE1, and MATE2, resulting in paradoxically increased thiamine plasma concentrations.

Theoretically, papain might increase the effects and side effects of warfarin.
In one case report, a patient previously stable on warfarin was found to have an international normalization ratio (INR) of 7.4, which was attributed to ingestion of a supplement containing papain from papaya extract.

Vitamin K can antagonize and reverse the therapeutic effects of warfarin.
Vitamin K antagonizes the effects of warfarin. Excessive vitamin K intake, either from supplements or from changes in the diet, can reduce the anticoagulant effect of warfarin.