Lv J, et al. - Given the cytochrome P-450 3A4 (CYP3A4) gene has been reported to contribute significantly to human liver microsomal oxidation of sufentanil and alfentanil, researchers investigated the frequency of CYP3A4 mutant allele and the correlation between sufentanil (an opioid analgesic) consumption and CYP3A4 genetic polymorphism. They found that in the parturients undergoing cesarean section and age-matched parturients with vaginal delivery, the frequency of the CYP3A4*1G (the mutant form of CYP3A) variant allele was 0.279. Findings demonstrated CYP3A4 genetic polymorphism correlated with sufentanil consumption. These data might aid the optimization of the anesthesia strategies and attenuation of their side effects.