Pharmacokinetic interactions between ritonavir-boosted darunavir and NNRTIs: a report of 3 cases.

Pharmacokinetic interactions among antiretroviral agents may influence the potency or toxicity of coadministered drugs. Here we present 3 patients with extensive protease inhibitor and NRTI resistance for whom ritonavir-boosted darunavir (DRV/r) and an NNRTI were components of a successful antiretroviral regimen. These cases provide a context in which to review pharmacokinetic data pertaining to the coadministration of DRV/r and an antiretroviral agent from the NNRTI class. Although dose adjustments are not currently recommended when DRV/r is given in combination with any of the commonly prescribed NNRTIs, plasma levels of both darunavir and these NNRTIs are altered when they are used concomitantly. Understanding these pharmacokinetic changes might allow clinicians to predict which patients may be more vulnerable to adverse effects or inadequate antiviral activity caused by this drug interaction.