Stavudine (Molecule of the Month for April 2007)
2'-3'-didehydro-2'-3'-dideoxythymidine, d4T, Zerit
Stavudine is a nucleoside analog reverse transcriptase inhibitor (NARTI) active against HIV. Stavudine was approved by the U.S. Food and Drug Administration (FDA) in 1994 for adults and in 1996 for pediatric use and again as an extended-release version for once-a-day dosing in 2001. When HIV infects a cell, reverse transcriptase copies the viral single stranded RNA genome into a double-stranded viral DNA. The viral DNA is then integrated into the host chromosomal DNA which then allows host cellular processes, such as transcription and translation to reproduce the virus. RTIs block reverse transcriptase's enzymatic function and prevent completion of synthesis of the double-stranded viral DNA thus preventing HIV from multiplying.
Stavudine is an analog of thymidine. It is phosphorylated by cellular kinases into active triphosphate. Stavudine triphosphate inhibits the HIV reverse transcriptase by competing with natural substrate, thymidine triphosphate. It also causes termination of DNA synthesis by incorporating into it.
Simultaneous use of AZT is not recommended, as it can inhibit the intracellular phosphorylation of stavudine. Other anti-HIV drugs do not possess this property.
Formal Chemical Name (IUPAC)
Update by Karl Harrison
(Molecule of the Month for April 2007 )