Emtricitabine

A nucleoside reverse transcriptase inhibitor (NRTI) for the prevention and treatment of HIV infection; also exhibits clinical activity against the hepatitis B virus (HBV) .HIV Infection Approved (In Vitro) :Emtricitabine has in vitro activity against both laboratory strains of HIV-1 and HIV-2 and clinical isolates of HIV-1. The 50% effective concentration (EC50) ranges from 0.002 to 1.5 μ mol/L, depending on the viral isolate and cell line used. Emtricitabine demonstrates in vitro synergy with zidovudine and stavudine and additive in vitro activity when combines with zalcitabine or didanosine. (In Vivo) :Reproductive and developmental toxicology studies are conducted with emtricitabine. Oral doses up to 1000 mg/kg/day provided daily area under the curve (AUC0→24) exposure to pregnant animals approximately 60- (mice) to 120-fold (rabbits) higher than that in humans at the recommended dose of 200 mg given once per day. In a mouse fertility study, emtricitabine had no effect on fertility, sperm count, or early embryonic development. There is no increased incidence of malformations in mouse and rabbit embryofetal toxicology studies. The development and fertility of F1 progeny are unaffected by emtricitabine in a mouse pre- and post-natal study. These data demonstrate a favorable pre-clinical reproductive safety profile for emtricitabine.