Adefovir dipivoxil, previously called bis-POM PMEA, is an orally-administered nucleotide analogue reverse transcriptase inhibitor (NtRTI), which works by blocking DNA polymerase, an enzyme that is crucial for the hepatitis B virus (HBV) to reproduce in the body.

It is approved for the treatment of chronic hepatitis B in adults with evidence of active viral replication and either evidence of persistent elevations in serum aminotransferases (ALT or AST) or histologically active disease. It is a failed treatment for HIV.

Adefovir was developed and is marketed by Gilead Sciences with the brand name Hepsera. It was originally developed for HIV with the brand name Preveon, but the U.S. Food and Drug Administration (FDA) refused to approve adefovir as a treatment for HIV in November 1999 due to the severity and frequency of kidney toxicity when dosed at 60 or 120mg. However, trials have found the 10mg dose of adefovir to be an effective and safe treatment for HBV. Adefovir became an approved treatment for HBV in the United States in September 2002 and in the European Union in March 2003.

The NtRTI class of antiretroviral drugs also includes the anti-HIV drug tenofovir (Viread), also developed by Gilead Sciences.

See also

• Hepsera web site (http://www.hepsera.com)