Objective: The influence of nevirapine (NVP) on lopinavir (LPV) pharmacokinetics was investigated by a population analysis based on a non-linear mixed-effect modelling method.
Methods: In this analysis, 95 HIV-1 infected patients were studied [52 treated with LPV/ritonavir (400/100 mg twice a day) plus nucleoside reverse transcriptase inhibitors (group A), 22 patients treated with LPV/ritonavir (533.3/133.3 mg twice a day) plus NVP (group B) and 21 patients treated with LPV/ritonavir (400/100 mg twice a day) plus NVP (group C)].
Results: The apparent clearance of LPV [mean+/-SD: 4.56+/-3.94 l h(-1) (group A) versus 7.14+/-1.77 l h(-1) (group B) versus 7.74+/-1.45 l h(-1) (group C)] was significantly (P <0.001) increased by the presence of NVP in the antiretroviral regimen and the mean trough plasma concentration of LPV was reduced in group C relative to group A [mean+/-SD: 2.23+/-1.35 mg/l versus 5.29+/-2.19 mg/l (P < 0.001)].
Conclusion: These results suggest an induction of LPV metabolism by NVP.