Drugs that induce P-gp result in decreased tenofovir AF absorption and plasma concentrations, which may lead to loss of therapeutic effect (eg, carbamazepine, oxcarbazepine, phenobarbital, phenytoin, rifabutin, rifampin, rifapentine, St John’s wort)
Drugs that inhibit P-gp and BCRP may increase tenofovir AF absorption and plasma concentration.
Coadministration of tenofovir AF with drugs that reduce renal function or compete for active tubular secretion may increase concentrations of tenofovir and other renally eliminated drugs, and this may increase the risk of adverse reactions
Some examples include acyclovir, cidofovir, ganciclovir, valacyclovir, valganciclovir, aminoglycosides, high-dose or long-term NSAD use