Amplified Stamina Fruit Blast Ingredients & Drug Interactions

Theoretically, the caffeine in yerba mate might increase the risk for stimulant adverse effects when used concomitantly with ephedrine.
Use of ephedrine with caffeine can increase the risk of stimulatory adverse effects. There is evidence that using ephedrine with caffeine might increase the risk of serious life-threatening or debilitating adverse effects such as hypertension, myocardial infarction, stroke, seizures, and death.

Theoretically, the caffeine in yerba mate might decrease the vasodilatory effects of adenosine and interfere with its use prior to stress testing.
Yerba mate contains caffeine. Some evidence shows that caffeine is a competitive inhibitor of adenosine and can reduce the vasodilatory effects of adenosine in humans. However, other research shows that caffeine does not seem to affect supplemental adenosine because high interstitial levels of adenosine overcome the antagonistic effects of caffeine. Still, some researchers recommend that methylxanthines, such as caffeine, as well as methylxanthine-containing products, should be stopped 24 hours prior to pharmacological stress tests. However, methylxanthines appear more likely to interfere with dipyridamole (Persantine) than adenosine-induced stress testing.

Theoretically, the caffeine in yerba mate may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Yerba mate contains caffeine. Caffeine is reported to have antiplatelet activity. Theoretically, it might increase the risk of bleeding when used concomitantly with these agents; however, this interaction has not been reported in humans.

Theoretically, the caffeine in yerba mate might reduce the efficacy of benzodiazepines.
Yerba mate contains caffeine. Caffeine can antagonize the anxiolytic effects of benzodiazepines.

Theoretically, the caffeine in yerba mate might increase the cardiac inotropic effects of beta-agonists, especially if taken in large amounts.
Yerba mate contains caffeine. Caffeine can increase cardiac inotropic effects of beta-agonists.

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

Theoretically, cimetidine might increase the levels and adverse effects of the caffeine contained in yerba mate.
Yerba mate contains caffeine. Cimetidine decreases caffeine clearance by 31% to 42%.

Theoretically, the caffeine in yerba mate might increase the levels and adverse effects of clozapine and acutely exacerbate psychotic symptoms.
Yerba mate contains caffeine. Caffeine might increase the effects and toxicity of clozapine. Caffeine doses of 400-1000 mg per day inhibit clozapine metabolism. Clozapine is metabolized by cytochrome P450 1A2 (CYP1A2). Although researchers speculate that caffeine might inhibit CYP1A2, there is no reliable evidence that caffeine affects CYP1A2. There is also speculation that genetic factors might make some patients more sensitive to an interaction between clozapine and caffeine.

Theoretically, the caffeine in yerba mate might decrease the vasodilatory effects of dipyridamole and interfere with its use prior to stress testing.
Yerba mate contains caffeine. Caffeine inhibits dipyridamole-induced vasodilation. Still, some researchers recommend that methylxanthines, such as caffeine, as well as methylxanthine-containing products, should be stopped 24 hours prior to pharmacological stress. Methylxanthines appear more likely to interfere with dipyridamole (Persantine) than adenosine-induced stress testing.

Theoretically, disulfiram might increase the levels and adverse effects of the caffeine in yerba mate.
Yerba mate contains caffeine. Disulfiram decreases the rate of caffeine clearance.

Theoretically, the caffeine in yerba mate might increase the risk of hypokalemia when used concomitantly with other diuretics.
Yerba mate contains caffeine. Caffeine, especially in excessive amounts, can reduce potassium levels due to stimulation of the sodium-potassium pump. Diuretics can also cause lower potassium levels.

Theoretically, estrogens might increase the levels and adverse effects of the caffeine in yerba mate.
Yerba mate contains caffeine. Estrogen inhibits caffeine metabolism.

Theoretically, the caffeine in yerba mate might reduce the effects of ethosuximide and increase the risk for convulsion.
Yerba mate contains caffeine. Animal research shows that caffeine 92.4 mg/kg can decrease the anticonvulsant activity of ethosuximide. However, this effect has not been reported in humans.

Theoretically, the caffeine in yerba mate might reduce the effects of felbamate and increase the risk for convulsion.
Yerba mate contains caffeine. Animal research shows that a high dose of caffeine 161.7 mg/kg can decreases the anticonvulsant activity of felbamate. However, this effect has not been reported in humans.

Theoretically, the caffeine in yerba mate might increase the levels and adverse effects of flutamide.
Yerba mate contains caffeine. In vitro evidence suggests that caffeine can inhibit the metabolism of flutamide. However, this effect has not been reported in humans.

Theoretically, fluvoxamine might increase the levels and adverse effects of the caffeine in yerba mate.
Yerba mate contains caffeine. Fluvoxamine reduces caffeine metabolism.

Theoretically, abrupt withdrawal of the caffeine in yerba mate might increase serum lithium levels.
Yerba mate contains caffeine, which has diuretic activity. When abruptly discontinued, it might alter the clearance of lithium. There are two case reports of lithium tremor that worsened upon abrupt coffee withdrawal.

Theoretically, use of yerba mate with midazolam might increase midazolam metabolite levels and adverse effects.
In vitro research shows that yerba mate extract containing 6.75% chlorogenic acid significantly inhibits the metabolism of midazolam via inhibition of cytochrome P450 3A4 (CYP3A4).

Theoretically, the caffeine in yerba mate might increase risk of a hypertensive crisis when used concomitantly with MAOIs.
Yerba mate contains caffeine. Caffeine has been shown to inhibit monoamine oxidase (MAO) A and B in laboratory studies. Concomitant intake of large amounts of caffeine with MAOIs might precipitate a hypertensive crisis. In a case report, a patient that consumed 10-12 cups of caffeinated coffee and took the MAOI tranylcypromine presented with severe hypertension. Hypertension was resolved after the patient switched to drinking decaffeinated coffee.

Theoretically, the caffeine in yerba mate might increase risk of hypertension when used concomitantly with nicotine.
Yerba mate contains caffeine. Concomitant use of caffeine and nicotine has been shown to have additive cardiovascular effects, including increased heart rate and blood pressure. Blood pressure was increased by 10.8/12.4 mmHg when the agents were used concomitantly.

Theoretically, the caffeine in yerba mate might decrease the effects of pentobarbital.
The caffeine in yerba mate might negate the hypnotic effects of pentobarbital.

Theoretically, the caffeine in yerba mate might reduce the effects of phenobarbital and increase the risk for convulsions.
Yerba mate contains caffeine. Animal research suggests that caffeine can decrease the anticonvulsant activity of phenobarbital. However, the exact mechanism of this interaction is unclear.

Theoretically, phenylpropanolamine might increase the risk of hypertension as well as the levels and adverse effects of the caffeine in yerba mate.
Yerba mate contains caffeine. Concomitant use of phenylpropanolamine and caffeine might cause an additive increase in blood pressure. Phenylpropanolamine also seems to increase caffeine serum levels.

Theoretically, the caffeine in yerba mate might reduce the effects of phenytoin and increase the risk for convulsions.
Yerba mate contains caffeine. Animal research suggests that caffeine can decrease the anticonvulsant activity of phenytoin. The effect does not seem to be related to the seizure threshold-lowering effects of caffeine. However, the exact mechanism of this interaction is unclear.

Theoretically, the caffeine in yerba mate might increase the levels and clinical effects of pioglitazone.
Yerba mate contains caffeine. Animal research suggests that caffeine can modestly increase the maximum concentration, area under the curve, and half-life of pioglitazone, and also reduce its clearance. This increased the antidiabetic effects of pioglitazone. However, the exact mechanism of this interaction is unclear.

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.

Theoretically, Boswellia serrata might increase the levels of CYP1A2 substrates.
In vitro research shows that Boswellia serrata gum resin inhibits CYP1A2 enzymes.

Theoretically, Boswellia serrata might increase the levels of CYP2C19 substrates.
In vitro research shows that Boswellia serrata gum resin inhibits CYP2C19 enzymes.

Theoretically, Boswellia serrata might increase the levels of CYP2C9 substrates.
In vitro research shows that Boswellia serrata gum resin inhibits CYP2C9 enzymes.

Theoretically, Boswellia serrata might increase the levels of CYP2D6 substrates.
In vitro research shows that Boswellia serrata gum resin inhibits CYP2D6 enzymes.

Theoretically, Boswellia serrata might increase or decrease the levels and clinical effects of CYP3A4 substrates.
In vitro research shows that Boswellia serrata gum resin inhibits CYP3A4 enzymes. Other in vitro research shows that Boswellia serrata extract inhibits CYP3A4 enzymes at most concentrations, although it may modestly induce enzyme activity at low concentrations.

Theoretically, Boswellia serrata might alter the effects of immunosuppressive drugs.
Some in vitro research suggests that Boswellia serrata extracts might inhibit mediators of autoimmune disorders such as leukotrienes and reduce production of antibodies and cell-mediated immunity. However, other in vitro research suggests that, when coupled with calcium ions, boswellic acids containing the keto group have immunostimulant properties within specific cell signaling pathways.

Theoretically, grape extracts may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
In vitro evidence suggests that grape extracts might decrease platelet aggregation.

Ingesting grape juice with cyclosporine can reduce cyclosporine absorption.
A small pharmacokinetic study in healthy young adults shows that intake of purple grape juice 200 mL along with cyclosporine can decrease the absorption of cyclosporine by up to 30% when compared with water. Separate doses of grape juice and cyclosporine by at least 2 hours to avoid this interaction.

Theoretically, grape juice might reduce the levels of CYP1A2 substrates.
A small pharmacokinetic study in healthy adults shows that ingestion of 200 mL of grape juice decreases phenacetin plasma levels. This is thought to be due to induction of CYP1A2.

Theoretically, grape seed extract may increase the levels of CYP2D6 substrates.
In vitro evidence suggests that grape seed extract might inhibit CYP2D6 enzymes. However, this interaction has not been reported in humans.

Theoretically, grape seed extract might increase the levels of CYP2E1 substrates.
In vitro and animal research suggests that grape seed proanthocyanidin extract inhibits CYP2E1 enzymes. However, this interaction has not been reported in humans.

It is unclear if grape seed extract inhibits or induces CYP3A4; research is conflicting.
In vitro evidence suggests that grape seed extract might inhibit CYP3A4 enzymes. However, evidence from animal research shows that grape seed extract may induce CYP3A4 in the liver. So far, these interactions have not been reported in humans.

Theoretically, long-term intake of grape seed extract might decrease the effects of midazolam.
Animal research shows that subchronic ingestions of grape seed extract can increase the elimination of intravenous midazolam by increasing hepatic CYP3A4 activity. Single doses of grape seed extract do not appear to affect midazolam elimination.

Grape juice might decrease phenacetin absorption.
A small pharmacokinetic study in healthy adults shows that ingestion of 200 mL of grape juice decreases phenacetin plasma levels. This is thought to be due to induction of cytochrome P450 1A2 (CYP1A2).

It is unclear if grape juice or grape seed extract inhibits CYP2C9; research is conflicting.
In vitro evidence shows that grape seed extract or grape juice might inhibit CYP2C9 enzymes. However, a small pharmacokinetic study in healthy adults shows that drinking 8 ounces of grape juice once does not affect the clearance of flurbiprofen, a probe-drug for CYP2C9 metabolism. The effects of continued grape juice consumption are unclear.

Theoretically, Indian long pepper might increase the risk of bleeding when taken with anticoagulant/antiplatelet drugs.
In vitro research shows that Indian long pepper extract inhibits platelet aggregation.

Theoretically, Indian long pepper might increase the risk of hypoglycemia when taken with antidiabetes drugs.
Animal research shows that piperine, a constituent of Indian long pepper, can reduce blood glucose levels. Monitor blood glucose levels closely. Dose adjustments might be necessary.

Theoretically, Indian long pepper might increase the effects and adverse effects of cyclosporine.
In vitro research shows that piperine, a constituent of Indian long pepper, increases the bioavailability of cyclosporine.

Theoretically, Indian long pepper might increase the effects and adverse effects of CYP3A4 substrates.
In vitro research shows that piperine, a constituent of Indian long pepper, inhibits CYP3A4.

Theoretically, Indian long pepper might increase blood levels of nevirapine.
A small pharmacokinetic study shows that piperine, a constituent of Indian long pepper, increases the plasma concentration and systemic exposure of nevirapine. However, no adverse effects were associated with the elevated plasma levels of nevirapine.

Theoretically, Indian long pepper might increase levels of P-glycoprotein substrates.
In vitro research shows that piperine, a constituent of Indian long pepper, can inhibit P-glycoprotein.

Theoretically, Indian long pepper might increase the sedative effects of pentobarbital.
Animal research shows that piperine, a constituent of Indian long pepper, can increase pentobarbitone-induced sleeping time.

Theoretically, Indian long pepper might increase blood levels of phenytoin.
A small pharmacokinetic study shows that piperine, a constituent of Indian long pepper, increases phenytoin serum levels and slows its elimination.

Theoretically, Indian long pepper might increase blood levels of propranolol.
A small pharmacokinetic study shows that piperine, a constituent of Indian long pepper, accelerates absorption and increases serum concentrations of propranolol.

Theoretically, Indian long pepper might increase blood levels of rifampin.
Piperine, a constituent of Indian long pepper, seems to increase absorption and serum levels of rifampin.

Indian long pepper might increase blood levels of theophylline.
A small pharmacokinetic study shows that piperine, a constituent of Indian long pepper, increases serum concentrations and slows elimination of theophylline.

Theoretically, Indian long pepper might increase the effects and adverse effects of amoxicillin.
Evidence from animal research shows that piperine, a constituent of Indian long pepper, increases the plasma levels of amoxicillin when taken concomitantly.

Theoretically, Indian long pepper might increase blood levels of carbamazepine.
A small pharmacokinetic study in patients taking carbamazepine 300 mg or 500 mg twice daily shows that a single 20 mg dose of purified piperine, which is a constituent of Indian long pepper, increases carbamazepine levels. Piperine may increase absorption by increasing blood flow to the GI tract, increasing the surface area of the small intestine, or by cytochrome P450 3A4 (CYP3A4) inhibition in the gut wall. Absorption was significantly increased by 7-10 mcg/mL/hour. The time to eliminate carbamazepine was also increased by 4-8 hours. Although carbamazepine levels were increased, this did not appear to increase side effects.

Theoretically, Indian long pepper might increase the effects and adverse effects of cefotaxime.
Animal research shows that piperine, a constituent of Indian long pepper, increases the plasma levels of cefotaxime when taken concomitantly.

Resveratrol may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Resveratrol seems to have antiplatelet effects.

Theoretically, resveratrol might increase levels of drugs metabolized by CYP1A2.
In vitro research shows that resveratrol can inhibit CYP1A2 enzymes. However, this interaction has not been reported in humans.

Theoretically, resveratrol might increase levels of drugs metabolized by CYP2C19.
In vitro research shows that resveratrol can inhibit CYP2C19 enzymes. However, this interaction has not been reported in humans.

Resveratrol might increase levels of drugs metabolized by CYP2E1.
In vitro research suggests that resveratrol inhibits CYP2E1 isoenzyme. Also, a pharmacokinetic study shows that taking resveratrol 500 mg daily for 10 days prior to taking a single dose of chlorzoxazone 250 mg increases the maximum concentration of chlorzoxazone by about 54%, the area under the curve of chlorzoxazone by about 72%, and the half-life of chlorzoxazone by about 35%. Chlorzoxazone is used as a probe drug for CYP2E1.

Theoretically, resveratrol might increase levels of drugs metabolized by CYP3A4.
In vitro research shows that resveratrol can inhibit the CYP3A4 enzyme. However, clinical research shows that taking resveratrol 3000 mg daily for 8 weeks does not necessitate dose adjustments to medications metabolized by CYP3A4.

Theoretically, schisandra might increase the levels and clinical effects of cyclophosphamide.
In vitro research shows that schisandra increases the concentration of cyclophosphamide, likely through inhibition of cytochrome P450 3A4. After multiple doses of the schisandra constituents schisandrin A and schisantherin A, the maximum concentration of cyclophosphamide was increased by 7% and 75%, respectively, while the overall exposure to cyclophosphamide was increased by 29% and 301%, respectively.

Schisandra can increase the levels and clinical effects of cyclosporine.
A small observational study in children with aplastic anemia found that taking schisandra with cyclosporine increased cyclosporine trough levels by 93% without increasing the risk of adverse events. However, the dose of cyclosporine was reduced in 9% of children to maintain appropriate cyclosporine blood concentrations.

Theoretically, schisandra might increase the levels and clinical effects of CYP2C19 substrates.
In vitro research shows that schisandra inhibits CYP2C19, and animal research shows that schisandra increases the concentration of voriconazole, a CYP2C19 substrate. Theoretically, schisandra may also inhibit the metabolism of other CYP2C19 substrates. This effect has not been reported in humans.

Theoretically, schisandra might decrease the levels and clinical effects of CYP2C9 substrates.
In vitro and animal research suggests that schisandra induces CYP2C9 enzymes. This effect has not been reported in humans.

Schisandra can increase the levels and clinical effects of drugs metabolized by CYP3A4.
Most clinical and laboratory research shows that schisandra, administered either as a single dose or up to twice daily for 14 days, inhibits CYP3A4 and increases the concentration of CYP3A4 substrates such as cyclophosphamide, midazolam, tacrolimus, and talinolol. Although one in vitro and animal study shows that schisandra may induce CYP3A4 metabolism, this effect appears to be overpowered by schisandra's CYP3A4 inhibitory activity and has not been reported in humans.

Schisandra can increase the levels and clinical effects of midazolam.
A small pharmacokinetic study in healthy adults shows that taking schisandra extract (Hezheng Pharmaceutical Co.) containing deoxyschizandrin 33.75 mg twice daily for 8 days and a single dose of midazolam 15 mg on day 8 increases the overall exposure to midazolam by about 119%, increases the peak plasma level of midazolam by 86%, and decreases midazolam clearance by about 52%. This effect has been attributed to inhibition of CYP3A4 by schisandra.

Schisandra might increase the levels and clinical effects of P-glycoprotein substrates.
In vitro research shows that schisandra extracts and constituents such as schisandrin B inhibit P-glycoprotein mediated efflux in intestinal cells and in P-glycoprotein over-expressing cell lines. Additionally, a small clinical study shows that schisandra increases the peak concentration and overall exposure to talinolol, a P-glycoprotein probe substrate. Theoretically, schisandra might inhibit the efflux of other P-glycoprotein substrates.

Schisandra can increase the levels and clinical effects of sirolimus.
A small pharmacokinetic study in healthy volunteers shows that taking 3 capsules of schisandra (Hezheng Pharmaceutical Company) containing a total of 33.75 mg deoxyschizandrin twice daily for 13 days and then taking a single dose of sirolimus 2 mg increases the overall exposure and peak level of sirolimus by two-fold. This effect is thought to be due to inhibition of cytochrome P450 3A4 by schisandra, as well as possible inhibition of the P-glycoprotein drug transporter.

Schisandra can increase the levels and clinical effects of tacrolimus.
Clinical research in healthy children and adults, transplant patients, and patients with nephrotic syndrome and various rheumatic immunologic disorders shows that taking schisandra with tacrolimus increases tacrolimus peak levels by 183% to 268%, prolongs or delays time to peak tacrolimus concentrations, increases overall exposure to tacrolimus by 126% to 343%, and decreases tacrolimus clearance by 19% to 73%. This effect is thought to be due to inhibition of P-glycoprotein drug transporter and CYP3A4 and CYP3A5 by schisandra. Some clinical and observational studies suggest that schisandra increases tacrolimus levels similarly in both expressors and non-expressors of CYP3A5, while other studies suggest it does so to a greater degree in CYP3A5 expressors than non-expressors. Animal research suggests that the greatest increase in tacrolimus levels occurs when schisandra is taken either concomitantly or up to 2 hours before tacrolimus, and clinical and observational research in humans suggests that schisandra may increase whole blood levels of tacrolimus and decrease clearance of tacrolimus in a dose-dependent manner.

Schisandra can increase the levels and clinical effects of talinolol.
A small pharmacokinetic study in healthy volunteers shows that taking schisandra extract 300 mg twice daily for 14 days with a single dose of talinolol 100 mg on day 14 increases the peak talinolol level by 51% and the overall exposure to talinolol by 47%. This effect is thought to be due to the possible inhibition of cytochrome P450 3A4 and P-glycoprotein by schisandra. tly.

Theoretically, schisandra might increase the levels and clinical effects of voriconazole.
Animal research shows that oral schisandra given daily for 1 or 14 days increases levels of intravenously administered voriconazole, a cytochrome P450 (CYP) 2C19 substrate. This effect is thought to be due to inhibition of CYP2C19 by schisandra. However, this interaction has not been reported in humans.

Theoretically, schisandra might decrease the levels and clinical effects of warfarin.
Animal research suggests that oral schisandra extract, given daily for 6 days, reduces levels of intravenously administered warfarin. This effect might be due to the induction of cytochrome P450 (CYP) 2C9 metabolism by schisandra. However, this interaction has not been reported in humans.

Concomitant use of alcohol and niacin might increase the risk of flushing and hepatotoxicity.
Alcohol can exacerbate the flushing and pruritus associated with niacin. Large doses of niacin might also exacerbate liver dysfunction associated with chronic alcohol use. A case report describes delirium and lactic acidosis in a patient taking niacin 3 grams daily who ingested 1 liter of wine. Advise patients to avoid large amounts of alcohol while taking niacin.

Theoretically, niacin might antagonize the therapeutic effects of uricosurics such as allopurinol.
Large doses of niacin can reduce urinary excretion of uric acid, potentially resulting in hyperuricemia. Doses of uricosurics such as allopurinol might need to be increased to maintain control of gout in patients who start taking niacin. People who have frequent attacks of gout despite uricosuric therapy should avoid niacin.

Theoretically, niacin may have additive effects when used with anticoagulant or antiplatelet drugs.
Several cases of clotting factor synthesis deficiency and coagulopathy have been reported in patients taking sustained-release niacin. Also, thrombocytopenia has been reported in patients treated with niacin or niacin plus lovastatin.

Niacin can increase blood glucose levels and may diminish the effects of antidiabetes drugs.
Niacin impairs glucose tolerance in a dose-dependent manner, probably by causing or aggravating insulin resistance and increasing hepatic production of glucose. In diabetes patients, niacin 4.5 grams daily for 5 weeks can increase plasma glucose by an average of 16% and glycated hemoglobin (HbA1c) by 21%. However, lower doses of 1.5 grams daily or less appear to have minimal effects on blood glucose. In some patients, glucose levels increase when niacin is started, but then return to baseline when a stable dose is reached. Up to 35% of patients with diabetes may need adjustments in hypoglycemic therapy when niacin is added.

Theoretically, niacin may increase the risk of hypotension when used with antihypertensive drugs.
The vasodilating effects of niacin can cause hypotension. Furthermore, some clinical evidence suggests that a one-hour infusion of niacin can reduce systolic, diastolic, and mean blood pressure in hypertensive patients. This effect is not observed in normotensive patients.

Bile acid sequestrants can bind niacin and decrease absorption. Separate administration by 4-6 hours to avoid an interaction.
In vitro studies show that colestipol (Colestid) binds about 98% of available niacin and cholestyramine (Questran) binds 10% to 30%.

Theoretically, concomitant use of niacin and gemfibrozil might increase the risk of myopathy in some patients.
A case of myopathy from concomitant use of niacin and gemfibrozil has been reported. Niacin alone has also been associated with cases of myopathy. Using gemfibrozil with niacin might further increase the risk of developing myopathy.

Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Niacin has been associated with cases of liver toxicity, especially when used in pharmacologic doses. Sustained-release niacin preparations appear to be associated with a higher risk of hepatotoxicity than immediate-release niacin.

Theoretically, concomitant use of niacin and statins might increase the risk of myopathy and rhabdomyolysis in some patients.
Some case reports have raised concerns that niacin might increase the risk of myopathy and rhabdomyolysis when combined with statins. However, a significantly increased risk of myopathy has not been demonstrated in clinical trials, including those using an FDA-approved combination of lovastatin and niacin (Advicor).

Theoretically, niacin might antagonize the therapeutic effects of uricosurics such as probenecid.
Large doses of niacin reduce urinary excretion of uric acid, potentially causing hyperuricemia. Doses of uricosurics such as probenecid might need to be increased to maintain control of gout in patients who start taking niacin. People who have frequent attacks of gout despite uricosuric therapy should avoid niacin.

Theoretically, niacin might antagonize the therapeutic effects of uricosurics such as sulfinpyrazone.
Large doses of niacin reduce urinary excretion of uric acid, potentially causing hyperuricemia. Doses of uricosurics such as sulfinpyrazone might need to be increased to maintain control of gout in patients who start taking niacin. People who have frequent attacks of gout despite uricosuric therapy should avoid niacin.

Theoretically, niacin might antagonize the therapeutic effects of thyroid hormones.
Clinical research and case reports suggests that taking niacin can reduce serum levels of thyroxine-binding globulin by up to 25% and moderately reduce levels of thyroxine (T4). Patients taking thyroid hormone for hypothyroidism might need dose adjustments when using niacin.

Theoretically, concomitant use of niacin and transdermal nicotine might increase the risk of flushing and dizziness.
Niacin and nicotine can both cause flushing and dizziness.

There is limited evidence that niacin may increase the anticoagulant effects of warfarin.
In a case report, a patient on warfarin developed an elevated international normalized ratio (INR) of 3.9 after taking niacin for two weeks. The patient's INR was previously stable, ranging between 2 and 3 in recent months, and no other medication changes were identified. The elevated INR returned to therapeutic range within 4 days following the discontinuation of niacin.

Large doses of aspirin might alter the clearance of niacin.
Aspirin is often used with niacin to reduce niacin-induced flushing. Doses of 80-975 mg aspirin have been used, but 325 mg appears to be optimal. Aspirin also seems to reduce the clearance of niacin by competing for glycine conjugation. Taking aspirin 1 gram seems to reduce niacin clearance by 45%. This is probably a dose-related effect and not clinically significant with the more common aspirin dose of 325 mg.

Theoretically, concomitant use might increase the risk for simulant adverse effects.
Black tea contains caffeine. There is evidence that using ephedrine with caffeine might increase the risk of serious life-threatening or debilitating adverse effects such as hypertension, myocardial infarction, stroke, seizures, and death. Tell patients to avoid taking caffeine with ephedrine and other stimulants.

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

Theoretically, black tea may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Black tea contains caffeine. Caffeine is reported to have antiplatelet activity. Theoretically, the caffeine in black tea might increase the risk of bleeding when used concomitantly with antiplatelet drugs. However, this interaction has not been reported in humans.

Theoretically, concomitant use of large amounts of black tea might increase cardiac inotropic effects of beta-agonists.
Black tea contains caffeine. Caffeine can increase cardiac inotropic effects of beta-agonists.

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

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

Theoretically, black tea might increase the levels and adverse effects of clozapine and acutely exacerbate psychotic symptoms.
Concomitant administration of black tea and clozapine might theoretically cause acute exacerbation of psychotic symptoms due to the caffeine in black tea. Caffeine can increase the effects and toxicity of clozapine. Caffeine doses of 400-1000 mg daily inhibit clozapine metabolism. Clozapine is metabolized by cytochrome P450 1A2 (CYP1A2). Researchers speculate that caffeine might inhibit CYP1A2. However, there is no reliable evidence that caffeine affects CYP1A2. There is also speculation that genetic factors might make some patients be more sensitive to the interaction between clozapine and caffeine.

Theoretically, concomitant use might increase the effects and adverse effects of caffeine found in black tea.
Black tea contains caffeine. Oral contraceptive drugs can decrease caffeine clearance by 40% to 65%.

Theoretically, concomitant use might increase the levels and adverse effects of caffeine.
Black tea contains caffeine. Caffeine is metabolized by CYP1A2,. Theoretically, drugs that inhibit CYP1A2 may decrease the clearance rate of caffeine from black tea and increase caffeine levels.

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

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

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

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

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

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

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

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

Theoretically, abrupt black tea withdrawal might increase the levels and adverse effects of lithium.
Black tea contains caffeine. Abrupt caffeine withdrawal can increase serum lithium levels. Two cases of lithium tremor that worsened with abrupt coffee withdrawal have been reported.

Theoretically, concomitant use might increase the risk of a hypertensive crisis.
Black tea contains caffeine. Caffeine has been shown to inhibit monoamine oxidase (MAO) A and B in laboratory studies. Concomitant intake of large amounts of caffeine with MAOIs might precipitate a hypertensive crisis. In a case report, a patient that consumed 10-12 cups of caffeinate coffee and took the MAOI tranylcypromine presented with severe hypertension. Hypertension was resolved after the patients switched to drinking decaffeinated coffee.

Theoretically, concomitant use might increase the risk of hypertension.
Black tea contains caffeine. Concomitant use of caffeine and nicotine has been shown to have additive cardiovascular effects, including increased heart rate and blood pressure. Blood pressure was increased by 10.8/12.4 mmHg when the agents were used concomitantly.

Theoretically, black tea might reduce the absorption of organic anion-transporting polypeptide (OATP) substrates.
In vitro, black tea extract inhibits organic anion-transporting polypeptide (OATP)2B1. OATP2B1 is expressed in the small intestine and liver and is responsible for the uptake of drugs and other compounds. In an animal model, black tea extract was found to inhibit the absorption of rosuvastatin, a substrate of OATP2B1. However, this effect has not been reported in humans.

Theoretically, black tea might decrease the effects of pentobarbital.
Black tea contains caffeine. Theoretically, caffeine might negate the hypnotic effects of pentobarbital.

Theoretically, black tea might reduce the effects of phenobarbital and increase the risk for convulsions.
Black tea contains caffeine. Animal research suggests that caffeine can decrease the anticonvulsant activity of phenobarbital. The exact mechanism of this interaction is unclear.

Theoretically, phenylpropanolamine might increase the risk of hypertension, as well as the levels and adverse effects of caffeine.
Black tea contains caffeine. Concomitant use of phenylpropanolamine and caffeine might cause an additive increase in blood pressure. Phenylpropanolamine also seems to increase caffeine serum levels.

Theoretically, black tea might reduce the effects of phenytoin and increase the risk for convulsions.
Black tea contains caffeine. Animal research suggests that caffeine can decrease the anticonvulsant activity of phenytoin. The effect does not seem to be related to the seizure threshold-lowering effects of caffeine. However, the exact mechanism of this interaction is unclear.

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

Theoretically, caffeine might decrease the vasodilatory effects of adenosine and interfere with its use prior to stress testing.
Some evidence shows that caffeine is a competitive inhibitor of adenosine and can reduce the vasodilatory effects of adenosine in humans. However, other research shows that caffeine does not seem to affect supplemental adenosine because high interstitial levels of adenosine overcome the antagonistic effects of caffeine. It is recommended that methylxanthines and methylxanthine-containing products be stopped 24 hours prior to pharmacological stress tests. However, methylxanthines appear more likely to interfere with dipyridamole (Persantine) than adenosine-induced stress testing.

Theoretically, caffeine may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Caffeine is reported to have antiplatelet activity. Theoretically, it might increase the risk of bleeding when used concomitantly with these agents; however, this interaction has not been reported in humans.

Theoretically, large amounts of caffeine might increase the cardiac inotropic effects of beta-agonists.

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

Theoretically, cimetidine might increase the levels and adverse effects of caffeine.
Cimetidine decreases the rate of caffeine clearance by 31% to 42%.

Caffeine might increase the levels and adverse effects of clozapine and acutely exacerbate psychotic symptoms.
Caffeine might increase the effects and toxicity of clozapine. Caffeine doses of 400-1000 mg per day inhibit clozapine metabolism. Clozapine is metabolized by cytochrome P450 1A2 (CYP1A2). Although researchers speculate that caffeine might inhibit CYP1A2, there is no reliable evidence that caffeine affects CYP1A2. There is also speculation that genetic factors might make some patients more sensitive to an interaction between clozapine and caffeine. In one case report, severe, life-threatening clozapine toxicity and multiorgan system failure occurred in a patient with schizophrenia stabilized on clozapine who consumed caffeine 600 mg daily.

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

Theoretically, disulfiram use might increase the levels and adverse effects of caffeine.
Disulfiram decreases the rate of caffeine clearance.

Theoretically, using caffeine with diuretic drugs might increase the risk of hypokalemia.
Caffeine, especially in excessive amounts, can reduce potassium levels due to stimulation of the sodium-potassium pump. Diuretics can also cause lower potassium levels.

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

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

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

Theoretically, caffeine might increase the levels and adverse effects of flutamide.
In vitro evidence suggests that caffeine can inhibit the metabolism of flutamide. However, this effect has not been reported in humans.

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

Abrupt caffeine withdrawal might increase the levels and adverse effects of lithium.
Caffeine has diuretic activity. When abruptly discontinued, caffeine may alter the clearance of lithium. There are two case reports of lithium tremor that worsened upon abrupt coffee withdrawal and 6 case reports of elevated serum lithium levels after reducing or eliminating caffeine intake. In one case, a male with schizoaffective disorder stabilized on lithium had an elevated lithium level after reducing his caffeine intake by 87%. At a later date, he increased his caffeine intake by 6-fold, resulting in a subtherapeutic lithium level and a recurrence of psychiatric symptoms.

Theoretically, concomitant use might increase the risk of a hypertensive crisis.
Caffeine has been shown to inhibit monoamine oxidase (MAO) A and B in laboratory studies. Concomitant intake of large amounts of caffeine with MAOIs might precipitate a hypertensive crisis. In a case report, a patient that consumed 10-12 cups of caffeinated coffee and took the MAOI tranylcypromine presented with severe hypertension. Hypertension was resolved after the patient switched to drinking decaffeinated coffee.

Theoretically, concomitant use might increase the risk of hypertension.
Concomitant use of caffeine and nicotine has been shown to have additive cardiovascular effects, including increased heart rate and blood pressure. Blood pressure was increased by 10.8/12.4 mmHg when the agents were used concomitantly.

Theoretically, caffeine might decrease the effects of pentobarbital.
Caffeine might negate the hypnotic effects of pentobarbital.

Theoretically, caffeine might reduce the effects of phenobarbital and increase the risk for convulsions.
Animal research suggests that caffeine can decrease the anticonvulsant activity of phenobarbital. However, the exact mechanism of this interaction is unclear.

Theoretically, phenylpropanolamine might increase the risk of hypertension, as well as the levels and adverse effects of caffeine.
Concomitant use of phenylpropanolamine and caffeine might cause an additive increase in blood pressure. Phenylpropanolamine also seems to increase caffeine serum levels.

Theoretically, caffeine might reduce the effects of phenytoin and increase the risk for convulsions.
Animal research suggests that caffeine can decrease the anticonvulsant activity of phenytoin. The effect does not seem to be related to the seizure threshold-lowering effects of caffeine. However, the exact mechanism of this interaction is unclear.

Theoretically, caffeine might increase the levels and clinical effects of pioglitazone.
Animal research suggests that caffeine can modestly increase the maximum concentration, area under the curve, and half-life of pioglitazone, and also reduce its clearance. This increased the antidiabetic effects of pioglitazone. However, the exact mechanism of this interaction is unclear.

Theoretically, quinolone antibiotics might increase the levels and adverse effects of caffeine.
Quinolones (also called fluoroquinolones) can decrease caffeine clearance by inhibiting cytochrome P450 1A2 (CYP1A2) enzyme.

Theoretically, concomitant use might increase the levels and adverse effects of both caffeine and riluzole.
Caffeine and riluzole are both metabolized by cytochrome P450 1A2 (CYP1A2), and concomitant use might reduce the metabolism of one or both agents.

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

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

Theoretically, guarana may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
In vitro and animal research suggests that guarana extract can inhibit platelet aggregation. This effect may be due to the caffeine in guarana, which is also reported to have antiplatelet activity. This interaction has not been reported in humans.

Theoretically, concomitant use might increase the clinical effects of beta-adrenergic agonists.
Guarana contains caffeine. Theoretically, concomitant use of large amounts of caffeine might increase cardiac inotropic effects of beta-agonists.

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

Theoretically, concomitant use might increase the effects and adverse effects of caffeine in guarana.
Guarana contains caffeine. Cimetidine decreases the rate of caffeine clearance by 31% to 42%.

Theoretically, guarana might increase the levels and adverse effects of clozapine and acutely exacerbate psychotic symptoms.
Guarana contains caffeine. Caffeine can increase the effects and toxicity of clozapine. Caffeine doses of 400-1000 mg per day inhibit clozapine metabolism. Clozapine is metabolized by cytochrome P450 1A2 (CYP1A2). Researchers speculate that caffeine might inhibit CYP1A2. However, there is no reliable evidence that caffeine affects CYP1A2. There is also speculation that genetic factors might make some patients more sensitive to the interaction between clozapine and caffeine.

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

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

Theoretically, using guarana with diuretic drugs might increase the risk of hypokalemia.
Guarana contains caffeine. Caffeine, especially in excessive amounts, can reduce potassium levels due to stimulation of the sodium-potassium pump. Diuretics can also lower potassium levels.

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

Theoretically, guarana might reduce the effects of ethosuximide and increase the risk for convulsions.
Guarana contains caffeine. Animal research shows that caffeine 92.4 mg/kg can decrease the anticonvulsant activity of ethosuximide. This effect has not been observed in humans.

Theoretically, guarana might reduce the effects of felbamate and increase the risk for convulsions.
Guarana contains caffeine. Animal research shows that a high dose of caffeine 161.7 mg/kg can decreases the anticonvulsant activity of felbamate. This effect has not been observed in humans.

Theoretically, guarana might increase the levels and adverse effects of flutamide.
Guarana contains caffeine. In vitro evidence shows that caffeine can inhibit the metabolism of flutamide. However, this effect has not been reported in humans.

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

Theoretically, abrupt guarana withdrawal might increase the levels and adverse effects of lithium.
Guarana contains caffeine. Theoretically, abrupt caffeine withdrawal might increase serum lithium levels. There are two case reports of lithium tremor that worsened upon abrupt coffee withdrawal.

Theoretically, concomitant use might increase the risk of a hypertensive crisis.
Guarana contains caffeine. Caffeine has been shown to inhibit MAO-A and -B in laboratory studies. Concomitant intake of large amounts of caffeine with MAOIs might precipitate a hypertensive crisis. In a case report, a patient that consumed 10-12 cups of caffeinated coffee and took the MAOI tranylcypromine presented with severe hypertension. Hypertension was resolved after the patient switched to drinking decaffeinated coffee.

Theoretically, concomitant use might increase the risk of hypertension.
Guarana contains caffeine. Concomitant use of caffeine and nicotine has been shown to have additive cardiovascular effects, including increased heart rate and blood pressure. Blood pressure was increased by 10.8/12.4 mmHg when the agents were used concomitantly.

Theoretically, guarana might decrease the effects of pentobarbital.
Guarana contains caffeine. In vivo evidence suggests that caffeine can negate the hypnotic effects of pentobarbital in humans. However, animal research suggests that guarana does not alter the hypnotic effect of pentobarbital.

Theoretically, guarana might reduce the effects of phenobarbital and increase the risk for convulsions.
Guarana contains caffeine. Animal research shows that caffeine can decrease the anticonvulsant activity of phenobarbital. The exact mechanism of this interaction is unclear.

Theoretically, phenylpropanolamine might increase the risk of hypertension, as well as the levels and adverse effects of caffeine.
Guarana contains caffeine. Concomitant use of phenylpropanolamine and caffeine might cause an additive increase in blood pressure. Phenylpropanolamine also seems to increase caffeine serum levels.

Theoretically, guarana might reduce the effects of phenytoin and increase the risk for convulsions.
Guarana contains caffeine. Animal research shows that caffeine can decrease the anticonvulsant activity of phenytoin. The effect does not seem to be related to the seizure threshold-lowering effects of caffeine. However, the exact mechanism of this interaction is unclear.

Theoretically, guarana might increase the levels and clinical effects of pioglitazone.
Guarana contains caffeine. Animal research suggests that caffeine can modestly increase the maximum concentration, area under the curve, and half-life of pioglitazone, and also reduce its clearance. This increased the antidiabetic effects of pioglitazone. However, the exact mechanism of this interaction is unclear.

Theoretically, concomitant use might increase the levels and adverse effects of both caffeine and riluzole.
Guarana contains caffeine. Caffeine and riluzole are both metabolized by cytochrome P450 1A2 (CYP1A2), and concomitant use might reduce the metabolism of one or both agents.

Theoretically, concomitant use might increase stimulant adverse effects.
Guarana contains caffeine. Due to the central nervous system (CNS) stimulant effects of caffeine, concomitant use with stimulant drugs can increase the risk of adverse effects.

Theoretically, concomitant use of L-arginine and ACE inhibitors may increase the risk for hypotension and hyperkalemia.
Combining L-arginine with some antihypertensive drugs, especially ACE inhibitors, seems to have additive vasodilating and blood pressure-lowering effects. Furthermore, ACE inhibitors can increase potassium levels. Use of L-arginine has been associated with hyperkalemia in some patients. Theoretically, concomitant use of ACE inhibitors with L-arginine may increases the risk of hyperkalemia.

Theoretically, concomitant use of L-arginine and ARBs may increase the risk of hypotension and hyperkalemia.
L-arginine increases nitric oxide, which causes vasodilation. Combining L-arginine with ARBs seems to increase L-arginine-induced vasodilation. Furthermore, ARBs can increase potassium levels. Use of L-arginine has been associated with hyperkalemia in some patients. Theoretically, concomitant use of ARBs with L-arginine may increases the risk of hyperkalemia.

Theoretically, concomitant use of L-arginine with anticoagulant and antiplatelet drugs might have additive effects and increase the risk of bleeding.
Preliminary research suggests that L-arginine infusions reduce platelet aggregation in humans. The clinical significance of this effect is unclear.

Theoretically, concomitant use of L-arginine might have additive effects with antidiabetes drugs.
Preliminary clinical research shows that L-arginine decreases blood glucose levels in patients with type 2 diabetes.

Theoretically, concomitant use of L-arginine and antihypertensive drugs may increase the risk of hypotension.
L-arginine increases nitric oxide, which causes vasodilation. Clinical evidence shows that L-arginine can reduce blood pressure in some individuals with hypertension. Furthermore, combining L-arginine with some antihypertensive drugs seems to have additive vasodilating and blood pressure-lowering effects.

Theoretically, concurrent use of isoproterenol and L-arginine might result in additive effects and hypotension.
Preliminary clinical evidence suggests that L-arginine enhances isoproterenol-induced vasodilation in patients with essential hypertension or a family history of essential hypertension.

Theoretically concomitant use of potassium-sparing diuretics with L-arginine may increases the risk of hyperkalemia.
Potassium-sparing diuretics can increase potassium levels. Use of L-arginine has been associated with hyperkalemia in some patients.

Theoretically, concurrent use of sildenafil and L-arginine might increase the risk for hypotension.
In vivo, concurrent use of L-arginine and sildenafil has resulted in increased vasodilation. Theoretically, concurrent use might have additive vasodilatory and hypotensive effects. However, in studies evaluating the combined use of L-arginine and sildenafil for erectile dysfunction, hypotension was not reported.

Theoretically, concomitant use of L-arginine and testosterone might have additive effects.
In clinical research, L-arginine increases the level of testosterone in male patients with erectile dysfunction. The clinical significance of this finding is unclear.

Theoretically, Ceylon cinnamon may have additive effects with antidiabetes drugs.
Ceylon cinnamon may lower blood glucose levels. Dose adjustments might be necessary.

Theoretically, Ceylon cinnamon might have additive effects with antihypertensive drugs and increase the risk of hypotension.
Animal research shows that Ceylon cinnamon extract has vasorelaxant properties and reduces blood pressure in rat models of hypertension, possibly via inhibition of calcium influx through L-type voltage-sensitive channels.

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.

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.

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.

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.

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.

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.

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.

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.