Association between MDR/CYP3A4/OPRM gene polymorphisms and the post-caesarean fentanyl analgesic effect on Chinese women.

Objective: Our study aimed to evaluate the association between the multidrug resistance 1 (MDR)/cytochrome P450 3A4 (CYP3A4)/μ-opioid receptor (OPRM) gene polymorphisms and the post-caesarean analgesic effect of fentanyl on Chinese women.

Methods: We recruited 240 patients who received lower segment caesarean section surgeries. Sanger sequencing was used to analyze the MDR1236C > T/CYP3A4*1G/OPRMA118G polymorphisms. We evaluated post-operative fentanyl consumption and the effect of intravenous analgesia in patients with different genotypes.

Results: 1. Subjects with the TT genotype at the 1236C > T polymorphism in the MDR gene consumed significantly more fentanyl than that consumed by subjects with the CC and CT genotypes in the first post-operative 24 h and 48 h (P < 0.05), and the MAP/HR/Cor/Ang-1 levels gradually increased immediately after surgery and in the first post-operative 24 h. 2. Subjects with the CYP3A4*1G/*1G genotype needed less fentanyl to achieve pain control than that needed by subjects carrying the CYP3A4*1/*1 and CYP3A4*1/*1G genotypes in the first post-operative 24 h and 48 h (P < 0.05), and the MAP/HR/Cor/Ang-1 levels gradually decreased immediately after surgery and in the first post-operative 24 h. 3. Subjects with the GG genotype at the A118G polymorphism in the OPRM gene consumed significantly more fentanyl than that consumed by subjects with the AA and AG genotypes in the first post-operative 24 h and 48 h (P < 0.05), and the MAP/HR/Cor/Ang-1 levels gradually increased immediately after surgery and in the first post-operative 24 h. 4. There were no significant differences in the adverse reactions to fentanyl in patients with different genotypes (P > 0.05).

Conclusion: These results indicated that the MDR/CYP3A4/OPRM gene polymorphisms influenced the fentanyl consumption and the physiological effects of intravenous analgesia in the Chinese women who received lower segment caesarean section surgeries. Moreover, the present study provides an important foundation and theoretical evidence for the gene-directed rationalization and individualization of medication before caesarean section surgeries.