Irvex Drug Interactions

No significant drug-drug pharmacokinetic (or pharmacodynamic) interactions have been found in interaction studies with hydrochlorothiazide, digoxin, warfarin and nifedipine.
In vitro studies show significant inhibition of the formation of oxidized irbesartan metabolites with the known cytochrome CYP2C9 substrates/inhibitors sulphenazole, tolbutamide and nifedipine. However, in clinical studies, the consequences of concomitant irbesartan on the pharmacodynamics of warfarin were negligible. Based on in vitro data, no interaction would be expected with drugs whose metabolism is dependent upon cytochrome P-450 isozymes 1A1, 1A2, 2A6, 2B6, 2D6, 2E1 or 3A4.
In seperate studies of patients recieving maintenance doses of warfarin, hydrochlorothiazide or digoxin, irbesartan administration for 7 days had no effect on the pharmacodynamics of warfarin (prothrombin time) or pharmacokinetics of digoxin. The pharmacokinetics of irbesartan were not affected  by co-administration of nifedipine or hydrochlorothiazide.