Cell disposition of raltegravir and newer antiretrovirals in HIV-infected patients: high inter-individual variability in raltegravir cellular penetration.

Objectives: The site of pharmacological activity of raltegravir is intracellular. Our aim was to determine the extent of raltegravir cellular penetration and whether raltegravir total plasma concentration (C(tot)) predicts cellular concentration (C(cell)).

Methods: Open-label, prospective, pharmacokinetic study on HIV-infected patients on a stable raltegravir-containing regimen.

Ritonavir-boosted atazanavir-lopinavir combination: a pharmacokinetic interaction study of total, unbound plasma and cellular exposures.

Objectives: To assess potential pharmacokinetic (PK) interactions between atazanavir (ATV, 300 mg, once daily) and lopinavir (LPV, 400 mg, twice daily), both boosted by ritonavir (RTV, 100 mg).

Design: Two-parallel groups, addition of LPV in patients receiving ATV (n=6), and addition of ATV in patients receiving LPV (n=7), with before/after comparisons.

Methods: Each group had two complete PK profiles before and 2 weeks after the addition of the second protease inhibitor (PI).