Abstract: Objective To investigate the relationship between plasma drug concentration and adverse reactions after taking efavirenz (EFV) standard dose (600mg) in HIV/AIDS patients, and to explore the factors affecting drug concentration, so as to provid basis forrational dose adjustment of EFV.Methods Total of 333 HIV-infected outpatients in Shenzhen the third people's hospital were enrolled (receiving EFV>3 months and viral load <500copies/ml).General demographic and clinical information were collected by patient interview. The plasma concentration of EFV in the patient's plasma was measured by high performance liquid chromatography and the clinical information of the patient was collected. The concentration and adverse drug reactions of EFV and the associated factors were analyzed by SPSS.Result sThe median plasma EFV concentration in the Han population of Shenzhen was 3.3 mg/L, the interquartile range (Q1 2.5, Q3 4.3). Among them, 229 (68.4%) were in the optimal therapeutic concentration window (1~4mg/L), 4 (1.2%) were less than 1mg/L, and 100 (30.3%) were greater than 4mg/L. Multivariate analysis showed that weight ≤60Kg and BMI≤22 Kg/m2 were significantly associated with EFV plasma concentrations greater than 4 mg/L. Exception of the dizziness symptom, there was no significant association between other adverse events of EFV and the highplasma EFV concentration greater than 4 mg/L.Conclusion The plasma EFV concentration in the Han population of Shenzhen is high, and BMI and body weight can better reflect the blood concentration. Therefore, dose adjustment of EFV can be performed based on BMI or body weight..

Key words: HIV/AIDS, Efavirenz, Adverse drug reactions, Plasma concentration, Body mass indexliposome