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This is a clinical test intended for Help: Drug Response

Clinical summary


Imported from PharmGKB

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 (e.g. 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.

Conditions tested

Target population


Information about genotype may be used as an aid to clinicians in determining therapeutic strategy and treatment dose for therapeutics


Not provided

Clinical validity


Not provided

Clinical utility


Not provided

Practice guidelines

  • PAGAA, 2020
    Panel on Antiretroviral Guidelines for Adults and Adolescents. Guidelines for the Use of Antiretroviral Agents in Adults and Adolescents with HIV. Department of Health and Human Services.
  • DailyMed Drug Label, 2020
    DailyMed Drug Label, SUSTIVA- efavirenz, 2020

Consumer resources

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