Importance of the field: The use of the first generation non-nucleoside reverse transcriptase inhibitor efavirenz (EFV) as a component of first-line antiretroviral therapy has been accepted worldwide. EFV is the only antiretroviral agent currently on the market that has been combined with emtricitabine and tenofovir disoproxil fumarate in a single tablet and administered once daily.
Areas covered in this review: This article reviews efficacy and safety data on EFV and the role of pharmacogenetics in EFV exposure. Published articles and conference presentations on EFV are reviewed.
What the reader will gain: CYP2B6 genetic polymorphisms influence the metabolism of EFV. The CYP2B6 G to T polymorphism at position 516 is shown to be associated with elevated plasma concentrations and an increase in neurotoxicity of EFV, while the wild-type genotype has been associated with sub-therapeutic concentrations of EFV, potentially leading to the development of viral resistance. This polymorphism is significantly higher in sub-Saharan Africans and African Americans as compared to Hispanic, European and Asian populations.
Take home message: The significance of CYP2B6 polymorphism in EFV exposure indicates the need for prospective clinical studies to evaluate the utility of genotype-driven dose adjustments in populations of diverse descent.