Tipranavir inhibits the replication of laboratory strains of HIV-1 and clinical isolates in acute models of T-cell infection, with 50% and 90% effective concentrations (EC50 and EC90) ranging from 0.03 to 0.07 µM (18-42 ng/ ml) and 0.07 to 0.18 µM (42-108 ng/ ml), respectively.