(3S,4aS,8aS)-N-tert-butyl-2-((2R,3R)-2-hydroxy-3-(3-hydroxy-2-methylbenzamido)-4-(phenylthio)butyl)decahydroisoquinoline-3-carboxamide methanesulfonate
A potent HIV protease inhibitor. It is used in combination with other antiviral drugs in the treatment of HIV in both adults and children.