Name: Azidothymidine (Zidovudine, AZT)
Mech: Thymidine analog. After phosph, inhib. viral RNA-dependent DNA polymerase (reverse transcriptase). Causes chain termination after incorporation.
Absorption: Oral bioavail 60-65%.
Distribution: good CSF
Metab.: Metab. to glucuronide. Antag. by ribavirin
Excretion, t½: 1 hr.
Toxicity/S.E.s: Granulocytopenia (45%), anemia (transfusions necessary 30%), headache, nausea, insomnia, myalgia.
Utility: Treatment of HIV. Decreases plasma HIV RNA, increases CD4 cells, decreases # of opportunistic infects, prolongs survival. Reduces risk of transmission by pregnant women to fetuses from 28% to 8%.