Drug Interaction Report

Theoretically, the concomitant administration of memantine and other drugs that undergo active renal tubular secretion may result in altered plasma levels of both drugs. The clinical significance is unknown. When hydrochlorothiazide/triamterene and memantine were coadministered in a clinical study, the bioavailability of hydrochlorothiazide decreased by 20% and there was no change in memantine or triamterene bioavailability.

Food enhances the oral absorption and bioavailability of tenofovir, the active entity of tenofovir disoproxil fumarate. According to the product labeling, administration of the drug following a high-fat meal increased the mean peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of tenofovir by approximately 14% and 40%, respectively, compared to administration in the fasting state. However, administration with a light meal did not significantly affect the pharmacokinetics of tenofovir compared to administration in the fasting state. Food delays the time to reach tenofovir Cmax by approximately 1 hour. Tenofovir disoproxil fumarate may be administered without regard to meals.