Emtricitabine

Emtricitabine structure

Emtricitabine is a nucleoside analogue and reverse transcriptase inhibitor used in combination with other agents for treatment and prevention of human immunodeficiency virus (HIV) infection and the acquired immunodeficiency syndrome (AIDS).

Liver safety of Emtricitabine

Emtricitabine does not appear to be a significant cause of drug induced liver injury, but may cause flares of disease in patients with underlying chronic hepatitis B virus (HBV) infection.

Mechanism of action of Emtricitabine

Emtricitabine (em" trye sye' ta been) is an L-enantiomer and substituted analogue of cytosine (5-fluorothiocytidine: FTC) and is active against both HIV and HBV, being similar in structure and activity to lamivudine. Emtricitabine is intracellularly phosphorylated to emtricitabine 5’-triphosphate which competes with the naturally occurring deoxycytidine 5’-triphosphate for incorporation into HIV DNA by the HIV reverse transcriptase, resulting in chain termination and inhibition of the polymerase activity. Emtricitabine was approved for use in HIV infection in the United States in 2006.

Current indications include treatment of HIV infection, the prophylaxis of HIV infection in cases of occupational exposure, nonoccupational exposure, and perinatal transmission. Emtricitabine is also active against HBV, but has not been specifically approved for use in hepatitis B. The combination of emtricitabine with tenofovir is used in many current antiretroviral regimens and is considered the therapy of choice in patients with HBV-HIV coinfection.

Dosage and administration for Emtricitabine

Emtricitabine is available as 200 mg capsules and in an oral solution as a single agent under the brand name of Emtriva; in 200 mg tablets in combination with tenofovir disoproxil fumarate (300 mg) as Truvada; in tablets in combination with tenofovir (300 mg) and efavirenz (600 mg) as Atripla; and in capsules in combination with tenofovir (300 mg), elvitegravir (150 mg) and cobicistat (150 mg) as Stribild. The recommended dose of emtricitabine in adults is 200 mg orally once daily. The combination formulations of Truvada, Atripla and Stribild are also given orally once daily.

Side effects of Emtricitabine

Side effects of attributable to emtricitabine are uncommon.

Manufacturer

Teva pharmaceuticals

• Dailymed label info on Emtricitabine
• FDA Emtricitabine