Pharmacokinetic exposure and virological efficacy of a reduced atazanavir dose.

We report our experience of reduced atazanavir dose in 6 HIV-infected patients on their first antiretroviral regimen, naïve to protease inhibitors and with no PI resistance mutations. In spite of plasmatic trough concentrations of atazanavir below the suggested minimum effective level in all of them, virological suppression (HIV-RNA <50 copies/mL) was obtained and persisted in all patients for a fairly long time. Despite the paucity of cases, this lends weight to the clinical importance of atazanavir MEC which is still being debated.