Gemfibrozil Concentrations Are Significantly Decreased in the Presence of Lopinavir-Ritonavir

OBJECTIVE: The objective of this study was to determine the influence of a 2-week course of lopinavir-ritonavir on the pharmacokinetics of the triglyceride-lowering agent, gemfibrozil. METHODS: The study was conducted as an open label, single-sequence pharmacokinetic study in healthy human volunteers. Gemfibrozil pharmacokinetic parameter values were compared using a Student t test after a single 600-mg dose was administered to healthy volunteers before and after 2 weeks of lopinavir-ritonavir (400/100 mg) twice daily. RESULTS: Fifteen healthy volunteers (eight males) completed the study. All study drugs were generally well tolerated and no subjects withdrew participation. The geometric mean ratio (90% confidence interval) for gemfibrozil area under the plasma concentration-time curve after 14 days of lopinavir-ritonavir compared with baseline was 0.59 (0.52, 0.67) (P < 0.001). All 15 study subjects experienced a reduction in gemfibrozil area under the plasma concentration-time curve after lopinavir-ritonavir (range, -6% to -74%). The geometric mean ratios for gemfibrozil apparent oral clearance and maximum concentration were 1.69 (1.41, 1.97) and 0.67 (0.49, 0.86) after 14 days of lopinavir-ritonavir versus baseline, respectively (P < 0.0001 and 0.01, respectively). Gemfibrozil elimination half-life did not change after lopinavir-ritonavir administration (P = 0.60). CONCLUSION: Lopinavir-ritonavir significantly reduced the systemic exposure of gemfibrozil by reducing gemfibrozil absorption. Clinicians treating HIV-infected patients with hypertriglyceridemia should be aware of this drug interaction.