Therapeutic Drug Monitoring and Pharmacogenetic Study of HIV-Infected Ethnic Chinese Receiving Efavirenz-Containing Antiretroviral Therapy with or without Rifampicin-Based Anti-Tuberculous Therapy

G516T polymorphisms and concomitant rifampicin use on the plasma efavirenz concentrations in HIV-infected Taiwanese. G516T polymorphism and plasma efavirenz concentrations with the use of polymerase-chain-reaction restriction fragment-length polymorphism and high-performance liquid chromatography, respectively.<0.001). Plasma efavirenz concentration >4 mg/L was noted in 38 (22.2%) patients, which was associated with a lower weight (per 10-kg increase, odds ratio, 0.52; 95% confidence interval, 0.33–0.83) and GT or TT genotype (odds ratio, 4.35; 95% confidence interval, 1.97–9.59) in multivariate analysis. 516 GT and TT genotypes and a lower weight are associated with higher plasma efavirenz concentrations