Favotan Drug Interactions

Blood pressure lowering effect of FAVOTAN may increase with other antihypertensive agents. Therefore, concomitant medication should be decided carefully.
Drug interactions reported with amlodipine or losartan single agents are summarized as follows: Amlodipine: Amlodipine has been safely administered with thiazide diuretics, alpha blockers, beta blockers, ACE inhibitors, long-acting nitrates, sublingual nitroglycerin, nonsteroidal anti-inflammatory medicines, antibiotics and oral hypoglycemic medicines.
In vitro human plasma data indicate that amlodipine has no effect on the protein binding of digoxin, phenytoin, warfarin, and indomethacin.
Effect of other agents on amlodipine tablets: Cimetidine: The co-administration of amlodipine with cimetidine did not alter the pharmacokinetics of amlodipine.
Grapefruit juice: The co-administration of 240 mL of grapefruit juice with a single oral dose of amlodipine 10 mg in 20 healthy volunteers had no significant effect on the pharmacokinetics of amlodipine.
Aluminium/Magnesium (antacid): The co-administration of the antacid Aluminium/Magnesium with a single dose of amlodipine had no significant effect on the pharmacokinetics of amlodipine.
Sildenafil: A single 100 mg dose of sildenafil in subjects with essential hypertension had no effect on the pharmacokinetic parameters of amlodipine. When amlodipine and sildenafil were used in combination, each agent independently exerted its own blood pressure lowering effect.
Effect of amlodipine tablets on other agents: Atorvastatin: The co-administration of multiple 10 mg doses of amlodipine with 80 mg of atorvastatin resulted in no significant change in the steady state pharmacokinetic parameters of atorvastatin.
Digoxin: The co-administration of amlodipine with digoxin did not change serum digoxin levels or digoxin renal clearance in normal volunteers.
Ethanol (alcohol): Single and multiple 10 mg doses of amlodipine had no significant effect on the pharmacokinetics of ethanol.
Warfarin: The co-administration of amlodipine with warfarin did not change the warfarin-prothrombin response time.
Cyclosporin: In pharmacokinetics study for cyclosporine, the co-administration of amlodipine did not significantly change the pharmacokinetics of cyclosporin.
Losartan: No significant drug interactions have been found in clinical pharmacokinetics study with hydrochlorothiazide, digoxin, warfarin, cimetidine and phenobarbital. However antihypertensive effects of losartan are potentiated by addition of hydrochlorothiazide. Rifampin, an inducer of drug metabolism, decreased the concentrations of losartan and its active metabolite. In humans, two inhibitors of P450 3A4 have been studied. Ketoconazole did not affect the conversion of the drug to the active metabolite after intravenous administration of losartan, and erythromycin had no clinically significant effect after oral administration. Fluconazole, an inhibitor of P450 2C9, decreased active metabolite concentration and increased losartan concentration. The pharmacodynamic interaction between losartan and inhibitors of P450 2C9 have not been examined. Subjects who were not able to metabolize this drug have been shown to have a specific, rare defect in cytochrome P450 2C9. These data suggested that the major enzyme that plays an important role in converting the drug to its active metabolite is not P450 3A4, but P450 2C9.
As with other drugs that block angiotensin II or its effects, concomitant use of potassium-sparing diuretics (e.g., spironolactone, triamterene, amiloride), potassium supplements, or salt substitutes containing potassium may lead to increase in serum potassium.
In patients with compromised renal function who are being treated with non-steroidal anti-inflammatory drugs (NSAIDs) including selective cyclooxygenase-2 inhibitors (COX-2 inhibitors), the co-administration of angiotensin II receptor antagonists like losartan may result in the further deterioration of renal function. These effects are usually reversible. NSAIDs including selective COX-2 inhibitors may diminish the effect of angiotensin II receptor antagonists like losartan. This interaction should be given consideration in patients taking NSAIDs including selective COX-2 inhibitors concomitantly with angiotensin II receptor antagonists.