Efavirenz (Sustiva)

Efavirenz (Sustiva) is an anti-HIV drug that reduces the amount of virus in the body. Anti-HIV drugs such as efavirenz slow down damage to the immune system and prevent the occurrence of AIDS-defining illnesses.

Efavirenz belongs to a class of drugs known as non-nucleoside reverse transcriptase inhibitors (NNRTIs). The enzyme reverse transcriptase converts single-stranded viral RNA into DNA. Drugs in the NNRTI class stop HIV from replicating within cells by binding near reverse transcriptase’s active site and inhibiting polymerase activity.

Efavirenz, formerly known by the codename DMP 266, was developed by Du Pont Pharma. It was approved for HIV treatment in the United States in 1998, and the European licence was granted in May 1999.

Efavirenz is marketed by Bristol-Myers Squibb under the trade name Sustiva in the United States, the United Kingdom, Ireland, France, Germany, Italy, and Spain. The trade name Stocrin is used by Merck Sharp & Dohme, who market the drug in other European countries, Australia, Brazil, Latin America, South Africa and other regions. Generic versions are manufactured in India as Efavir (made by Cipla), Estiva (Genixpharma), Viranz (Aurobindo) and Efferven (Ranbaxy).

Efavirenz is also available in a triple-drug combination tablet called Atripla. This tablet is the first once-daily tablet containing a complete HIV treatment regimen. It contains 600mg efavirenz, 200mg FTC (emtricitabine), and 300mg tenofovir. It was approved in the United States in July 2006 and in the European Union and Canada in late 2007.