Data during the development of lopinavir/ritonavir showed that lower drug doses had similar efficacy to the standard dose of 400/100mg twice daily. Lower drug doses are also associated with limited toxicity and cost.~The purpose of this study is to assess the pharmacokinetics of plasma lopinavir/ritonavir following administration to male and female HIV-negative volunteers of 400/100mg, 200/150mg and 200/50mg lopinavir/ritonavir twice daily. Each dosing phase will last for 7 days and each phase will be separated by a 7-day wash-out period. Pharmacokinetic evaluations will be made over a 12-hour interval at the end of each dosing phase.~Healthy subjects as determined by their medical history and physical examinations will be eligible to participate in the study. HIV-positive subjects will not be recruited as there is a risk that HIV-resistant mutations will be selected by an experimentally reduced dose of lopinavir/ritonavir. There is no reason to presume that there is any meaningful difference in the metabolic processing of lopinavir/ritonavir between HIV-infected and HIV-uninfected people.
The purpose of this study is to assess the pharmacokinetics of plasma lopinavir/ritonavir over a 12-hour dosing interval, following administration to male and female HIV-negative healthy volunteers of:~Lopinavir/ritonavir 400/100 mg twice daily~Lopinavir/ritonavir 200/150 mg twice daily~Lopinavir/ritonavir 200/50 mg twice daily