Stavudine

Stavudine (d4T, brand name Zerit) is an orally bioavailable nucleoside analog reverse transcriptase inhibitor (NARTI) active against HIV. Stavudine triphosphate inhibits the HIV reverse transcriptase in vitro by competing with natural substrate, thymidine triphosphate. Stavudine also causes termination of DNA replication by incorporating into the DNA strand. In clinical studies, stavudine has excellent oral bioavailability in excess of 80%.