Pharmacokinetics of stavudine by oral administration to healthy Mexican volunteers.

Stavudine (d4T) is a thymidine nucleoside analogue which is intracellularly phosphorylated to an active metabolite, stavudine 5'-triphosphate. This metabolite inhibits HIV replication, either by competing with thymidine 5'-triphosphate for incorporation into viral DNA by reverse transcriptase or by causing premature termination of the viral chain after incorporation [2]. The stavudintriphosphate even interferes with the DNA polimerase β and γ [3,4]. Stavudine inhibits viral reverse transcriptase as do zidovudine (AZT), didanosine (ddI), zalcitabine (ddC) and lamivudine (3TC), which comprise the family of nucleoside HIV-reverse transcriptase inhibitors. Stavudine is currently approved by the US Food and Drug Administration for the treatment of patients who have become intolerant to, or have failed to respond to zidovudine, didanosine or zalcitabine therapy [5].