title: A pharmacogenomic prospective randomized controlled trial of CYP2B6 polymorphisms and efavirenz dose adjustment among HIV-infected Thai patients: a pilot study.
abstract: OBJECTIVE
  We aimed at comparing clinical/immunological outcomes in human immunodeficiency virus (HIV)-infected patients who were treated with CYP2B6-guided and conventional efavirenz (EFV) therapy.
  
  
  METHODS
  This study was a 24-week prospective randomized controlled trial. Eligible patients were HIV-infected adults yet to start antiretroviral therapy. Twenty-four HIV-infected patients were recruited and randomly assigned to genotype CYP2B6 polymorphism before ART initial dose. Patients with CYP2B6 *6/*6 received 400 mg EFV-based regimen and those with other genotypes received 600 mg EFV-based therapy.
  
  
  RESULTS
  For CYP2B6 polymorphism, 12 patients were extensive metabolizers, ten patients were intermediate metabolizers, and only two patients were poor metabolizers (*6/*6). The overall mean EFV plasma concentrations were similar in both groups. The mean drug concentrations (standard deviation) were 1.675 (0.963), 1.445 (0.778), and 1.899 (0.808) µg/mL at week 4, 12, and 24, respectively. The CYP2B6 *6/*6 patient who received low dose of EFV had lower mean EFV level than those who received a normal dose, 1.916 versus 3.915 µg/mL (P<0.001), respectively. Seventy percent of the patients had neuropsychiatric adverse events, especially dizziness.
  
  
  CONCLUSIONS
  There was a trend toward association of the CYP2B6 polymorphism and plasma EFV concentrations in this study. Reduced EFV dose should be considered in CYPB6 *6/*6 carrier to keep the drug concentration in therapeutic range.
authors.affiliation: Deparment of Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: Pansachee
authors.initials: P
authors.lastname: Damronglerd
authors.affiliation: Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand ; Laboratory for Pharmacogenomics, Somdech Phra Debaratana Medical Center, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Chonlaphat
authors.initials: C
authors.lastname: Sukasem
authors.affiliation: Department of Medicine, Faculty of Medicine, Maharat Nakhon Ratchasima Hospital, Nakhon Ratchasima, Thailand.
authors.forename: Wilawan
authors.initials: W
authors.lastname: Thipmontree
authors.affiliation: Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand ; Laboratory for Pharmacogenomics, Somdech Phra Debaratana Medical Center, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Apichaya
authors.initials: A
authors.lastname: Puangpetch
authors.affiliation: Deparment of Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: Sasisopin
authors.initials: S
authors.lastname: Kiertiburanakul
keywords: CYP2B6 polymorphism; HIV-infected patient; Thai; efavirenz; pharmacogenetics; prospective study