A synthetic nucleoside, analog of didehydro-3-deoxythymidine with potent antiretroviral activity. In vivo, stavudine is phosphorylated by cellular kinases to the active metabolite stavudine triphosphate; this metabolite inhibits the activity of HIV reverse transcriptase both by competing with the natural substrate deoxythymidine triphosphate and by incorporation into viral DNA causing a termination of DNA chain elongation (due to the lack the essential 3'-OH group). or A drug that belongs to the family of drugs called nucleoside analogs. It is used to treat infection caused by viruses.