CYP3A4 * 1G Genetic Polymorphism Influences Metabolism of Fentanyl in Human Liver Microsomes in Chinese Patients.

Purpose: This study aimed to investigate whether CYP3A4*1G genetic polymorphism influences the metabolism of fentanyl in human liver microsomes in Chinese patients.

Methods: The human liver microsomes were obtained from 88 hepatobiliary surgery patients who accepted liver resection surgery in this study. A normal liver sample (confirmed by the Department of Pathology) was taken from the outer edge of the resected tissue. The metabolism of fentanyl in human liver microsomes was studied. The concentration of fentanyl was measured by high performance liquid chromatography. The CYP3A4*1G variant allele was genotyped using the PCR restriction fragment length polymorphism method.

Results: The frequency of the CYP3A4*1G variant allele was 0.188 in the 88 Chinese patients who had received hepatobiliary surgery. The metabolic rate of fentanyl in patients homozygous for the *1G/*1G variant (0.85 ± 0.37) was significantly lower than that in patients bearing the wild-type allele *1/*1 (1.89 ± 0.58) or in patients heterozygous for the *1/*1G variant (1.82 ± 0.65; p < 0.05). There were no gender-related differences in the metabolic rate of fentanyl (p > 0.05) nor was there any correlation between age and metabolic rate of fentanyl (p > 0.05). Results from different hepatobiliary diseases showed no significant difference in the metabolic rate of fentanyl (p > 0.05). The difference of CYP3A4 mRNA among different CYP3A4*1G variant alleles was significant (p < 0.05). There was positive correlation between CYP3A4 mRNA and metabolic rate of fentanyl (p < 0.01).

Conclusions: CYP3A4*1G genetic polymorphism decreases the metabolism of fentanyl. There is a positive correlation between CYP3A4 mRNA level and metabolism of fentanyl.