Clinical use of lopinavir/ritonavir in a salvage therapy setting: pharmacokinetics and pharmacodynamics.

Lopinavir/ritonavir was administered to 35 HIV-infected patients after therapeutic failure with other protease inhibitors. The pharmacokinetics (trough concentrations) and baseline viral genotype were determined, together with the immunovirological outcome. The 22 responders had significantly higher mean lopinavir concentrations and lower baseline numbers of mutations. On multivariate analysis, a lopinavir concentration of 5.7 microg/ml or greater was an independent predictor of viral suppression over a 9-month follow-up period.