Metabolism and disposition of the HIV-1 protease inhibitor lopinavir (ABT-378) given in combination with ritonavir in rats, dogs, and humans.

Purpose: The objective of this study was to examine the metabolism and disposition of the HIV protease inhibitor lopinavir in humans and animal models.

Methods: The plasma protein binding of [14C]lopinavir was examined in vitro via equilibrium dialysis technique. The tissue distribution of radioactivity was examined in rats dosed with [14C]lopinavir in combination with ritonavir.