Implications of Efavirenz Pharmacogenetics when Switching from Efavirenz- to Dolutegravir-containing Antiretroviral Regimens.

Many patients switch from efavirenz- to dolutegravir-based regimens. In a Phase 1 dolutegravir-efavirenz interaction study, mean dolutegravir Cmin decreased by 60% and 85% among CYP2B6 normal and slow/intermediate metabolizers, respectively. Mean efavirenz half-life was 2.7-times greater in slow versus normal metabolizers. Slow metabolizers will experience more prolonged subtherapeutic dolutegravir concentrations.