Sign Out
Drugs affecting Hepatic Microsomal Enzymes: Concomitant use of oral contraceptives and the inducers of hepatic microsomal cytochrome P-450 (CYP) enzyme may decrease contraceptive efficacy and increase breakthrough bleeding. The inducer of hepatic microsomal enzymes including barbiturates, bosentan, carbamazepine, felbamate, griseofulvin, oxcarbazepine, phenytoin, rifampicin, topiramate and St. John's wort.
Antiretroviral agents: Concomitant use of oral contraceptives and some HIV-protease inhibitors or nonnucleoside reverse transcriptase inhibitors may reduce the efficacy of the oral contraceptives.
