Tenofovir (Viread)

Tenofovir (Viread) is an antiviral drug that is approved for the treatment of HIV infection. It is able to reduce the amount of HIV in the blood, help prevent or reverse damage to the immune system and reduce the risk of AIDS-related illnesses. It is also an experimental treatment for hepatitis B .

Tenofovir is made by Gilead Sciences Inc. and is marketed as Viread. During the early phase of development, tenofovir was known by the code-name GS 4331 and its chemical abbreviation bis(POC)PMPA or PMPA.

Tenofovir belongs to the nucleotide reverse transcriptase inhibitor (NtRTI) class of drugs. Like the nucleoside analogue reverse transcriptase inhibitors (NRTIs), NtRTIs inhibit an enzyme called reverse transcriptase, which is essential to the process of viral replication. For more information on how these drugs work, see Reverse transcriptase inhibitors.

Tenofovir is also available in a fixed-dose combination tablet called Truvada. Truvada contains 300mg tenofovir and 200mg FTC (emtricitabine, Emtriva). It was approved in the United States in August 2004 and in the European Union in November 2004.

Tenofovir is also available in two triple-drug combination tablets Atripla, the first once-daily tablet containing a complete HIV treatment regimen, contains 600mg efavirenz, 200mg FTC, and 300mg tenofovir. It was approved in the United States in July 2006 and in late 2007 by the European Union. Eviplera is a fixed-dose tablet combining 25mg rilpivirine, 200mg FTC (emtricitabine), and 245mg tenofovir. It was licensed in the United States for use in HIV-positive adults in August 2011 and approved for use in the European Union in November 2011.