In this research project, we will study the genetic determinants that influence the pharmacokinetics of antiretroviral drugs used in the treatment of diseases caused by the HIV. We will put a particular emphasis on viral protease inhibitors (atazanavir, saquinavir, lopinavir, ritonavir)and non-nucleosides reverse transcriptase inhibitors (nevirapine and efavirenz). For those drugs, the clinician often faces a double therapeutic risk, either of insufficient dosing (clinical inefficacy and emergence of resistance) or of excessive dosing (toxicity). The optimization of drug dosing is especially crucial because some of these drugs often represent the last choice in multi-resistant patients.