Purpose of review: The purpose of this study is to review recent and relevant pharmacology data for three HIV integrase inhibitors: raltegravir (marketed), dolutegravir, and elvitegravir (both in phase III drug development).
Recent findings: Data from January 2011 to April 2012 were evaluated. These data better characterized integrase inhibitor pharmacokinetics, assessed dosing regimens, and investigated previously undescribed drug-drug interactions. Due to formulation challenges, raltegravir inter-patient and intra-patient pharmacokinetic variability is high. Twice-daily 400 mg dosing has been shown to be clinically superior to 800 mg once-daily dosing. A pediatric formulation of raltegravir with less variable pharmacokinetics and greater bioavailability was US Food and Drug Administration (US FDA)-approved in December 2011. Cobicistat-boosted elvitegravir, and the second-generation integrase inhibitor dolutegravir, have lower pharmacokinetic variability and are dosed once daily. Dolutegravir drug interactions are similar to raltegravir, whereas boosted elvitegravir participates in additional CYP3A-mediated interactions.
Summary: Raltegravir's potent antiretroviral activity has resulted in widespread use in both treatment-naïve and experienced patients. Dolutegravir and cobicistat-boosted elvitegravir have some pharmacokinetic advantages. Pharmacokinetic data in special populations (pregnancy, pediatrics) to optimize dosing are still required.