Emtricitabine + Tenofovir Alafenamide is a combination of two medicines, emtricitabine and tenofovir alafenamide. They belong to a class of medications called nucleoside reverse transcriptase inhibitors (NRTIs). Emtricitabine interrupts the virus life cycle by inhibiting a crucial enzyme called HIV-1 reverse transcriptase. Tenofovir alafenamide is converted to tenofovir diphosphate which gets incorporated into viral DNA, resulting in the inhibition of HIV replication.