New CPIC Guideline: CYP2B6 and efavirenz

The CPIC Guideline for CYP2B6 and efavirenz is now published in Clinical Pharmacology and Therapeutics. The accepted article can be viewed on the PharmGKB pages for efavirenz, CYP2B6, and on the CPIC website.

Efavirenz is a non-nucleoside reverse transcriptase inhibitor widely used worldwide to treat HIV-1 infection. It is predominantly metabolized into inactive metabolites by cytochrome P450-2B6 (CYP2B6). Genetic variants in CYP2B6 (eg. CYP2B6*6 and *18), along with other genetic and non-genetic factors, are known to influence variability in efavirenz response. Patients with certain CYP2B6 genetic polymorphisms may be at increased risk for adverse effects, particularly central nervous system toxicity and treatment discontinuation. 

The CPIC guideline and supplement summarize evidence from the literature and provide therapeutic recommendations for efavirenz based on CYP2B6 genotype. For therapeutic recommendations and further details, please refer to the CPIC Guideline for CYP2B6 and efavirenz-containing antiretroviral therapy.