3TC (lamivudine, Epivir) is an antiviral drug that reduces the amount of HIV in the body. Anti-HIV drugs such as 3TC slow down or prevent damage to the immune system, and reduce the risk of developing AIDS-related illnesses. 3TC is also active against hepatitis B virus.

3TC is one of the nucleoside analogue reverse transcriptase inhibitors (NRTIs). These drugs disrupt an HIV protein or enzyme called reverse transcriptase, which is involved in making new viruses. For more information about how NRTIs work, see Reverse transcriptase inhibitors.

In 1996, 3TC was licensed in Europe as a treatment for HIV when used in combination with other anti-HIV drugs. It was discovered by BioChem Pharma and is manufactured by GlaxoSmithKline under the tradename Epivir.

Generic versions of 3TC include Lamivir, made by Cipla, Heptavir, made by Genixpharma, Lamivox, made by Aurobindo, and Virolam, made by Ranbaxy. Virolam and Lamivox were granted tentative approval by the United States Food and Drug Administration (FDA) in May and June 2005. This means that the drugs can be used outside the United States under the President’s Emergency Plan for AIDS Relief (PEPFAR).

3TC is available combined with AZT (zidovudine) in one pill, known by the trade name Combivir from GlaxoSmithKline. Each Combivir pill contains 150mg 3TC and 300mg AZT. Generic versions of this co-formulation inlcude Duovir, made by Cipla, Virocomb, made by Ranbaxy, and Zidolam, made by Genixpharma. Zidovex-L, Aurobindo’s version of the fixed dose combination of 3TC and AZT was granted tentative approval by the FDA in July 2005.

A pill that combines 300mg AZT, 150mg 3TC and 300mg abacavir, known as Trizivir, is also available from GlaxoSmithKline. It was approved in the United States in November 2000 and in the European Union in March 2001. Ranbaxy make a generic version of this combination, called Abac-ALZ.

GlaxoSmithKline also produces a fixed-dose combination of 300mg 3TC with 600mg abacavir, which is suitable for once-daily dosing. It is marketed as Kivexa in Europe and as Epzicom in the United States.

3TC is a component of numerous other fixed-dose combination pills manufactured by Indian companies including:

• 3TC and d4T (stavudine): Lamivir-S (Cipla), Lamistar 30 & 40 (Genixpharma), Stavex-L (Aurobindo),Virolis (Ranbaxy).
• 3TC, d4T and nevirapine: Triomune (Cipla), Nevilast (Genixpharma), Stavex LN (Aurobindo), Viro LNS (Ranbaxy; also removed from the WHO’s prequalification list in August 2004).
• 3TC, AZT and nevirapine: Duovir-N (Cipla), Zidovex-LN (Aurobindo).
• 3TC, ddI (didanosine) and efavirenz: Odivir Kit (Cipla).

3TC is also approved as a treatment for hepatitis B virus (HBV). In the European Union it is known by the trade name Zeffix and in the United States as Epivir-HBV.