Related Experiment Video
Updated: Mar 29, 2026

Rapid Screening of HIV Reverse Transcriptase and Integrase Inhibitors
Published on: April 9, 2014
A pharmacogenomic prospective randomized controlled trial of CYP2B6 polymorphisms and efavirenz dose adjustment among
Pansachee Damronglerd1, Chonlaphat Sukasem2, Wilawan Thipmontree3
1Deparment of Medicine, Mahidol University, Bangkok, Thailand.
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.
Discussion:
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.
More Related Videos
Related Concept Videos
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes
Pharmacogenetics of Drug Metabolism: Overview
Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Effect of Hepatic Disease on Pharmacokinetics: Dose Adjustments Due to Hepatic Impairment
Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase

