RESUMEN
Objective To investigate the effects of CYP3A4* 1G genetic polymorphism on fentanyl pharmadynamics after intravenous injection in healthy female velunteers,Methods Twenty-eight healthy female volunteers aged 18-25 yr weighing 45-70 kg were enrolled in this study.The CYP3A4 * 1G genetic polymorphic sites were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).The volunteers were assigned into 3 groups according to their genotypes:group Ⅰ wild homozygote ; group Ⅱ mutation heterozygote and group Ⅲ mutation homozygote.Fentanyl 5 μg/kg was injected iv over 1 min.Pain threshold was measured using electrical stimulation before and at 45,150 and 240 min after fentanyl injection.Results Pain threshold was significantly higher at 45 and 150 min after iv fentanyl injection in mutation homozygote group than in mutation heterozygote group and wild homozygote group.There was no significant difference in pain threshold between mutation heterozygote group and wild homozygote group.Conclusion CYP3A4* 1G genetic mutation can enhance the analgesic efficacy of fentanyl after intravenous injection in healthy female volunteers.