Emtricitabine (FTC, Emtriva)
Emtricitabine is the 5-fluorinated derivative of lamivudine. It has same safetyand efficacy, and can be given once daily. It is available alone or in a fixeddose combination with tenofovir (Truvada). Resistance to emtricitabine is conferred by the M184V mutation, which is the main cause of resistance to lamivudine, so cross-resistance is expected.