Lopinavir/Ritonavir Pharmacokinetics in a Substitution of High-Dose Soft-Gelatin Capsule to Tablet Formulation

Guidelines recommend that when soft-gelatin capsules of lopinavir/ritonavir are co-administered with CYP3A4-inducing agents, doses should be increased to 4 capsules (533 mg/133 mg) twice daily. No evidence is available to guide dosing of lopinavir/ritonavir in tablet formulation in this setting. A single-center study is conducted to compare the pharmacokinetics of high-dose lopinavir/ritonavir in 34 patients on stable HAART regimens including 4 soft-gelatin capsules twice daily who then switch to 3 tablets (600 mg/150 mg) twice daily. Median C(min) on soft-gelatin capsule and tablets is 4700 ng/mL (interquartile range [IQR] 2310, 6000 ng/mL) and 5640 ng/mL (IQR 4290, 8080 ng/mL), respectively, for those on inducing agents (n = 17). For patients not on inducing agents (n = 17), median C(min) on soft-gelatin capsule and tablets is 5170 ng/mL (IQR 3640, 6210 ng/mL) and 5640 ng/mL (IQR 4290, 8080 ng/mL), respectively. Among treatment-experienced patients on lopinavir/ritonavir capsules 533/133 mg twice daily, a switch to tablets 600/150 mg twice daily produces comparable pharmacokinetics, regardless of whether they receive concomitant CYP3A4-inducing antiretroviral agents.