CYP2B6 and tuberculosis: Efavirenz is known to induce its own metabolism over 16 weeks of efavirenz-based ART in adults especially in those with a CYP2B6*1/*1 genotype through 8-hydroxylation (28), but efavirenz had no significant additive or synergistic effect over that due to ongoing rifampin-containing therapy in TB/HIV-coinfected adults (29).