Association of μ-opioid receptor gene (OPRM1) haplotypes with postoperative nausea and vomiting

Genetic variants, such as single-nucleotide polymorphisms (SNPs), of the μ-opioid receptor gene ( OPRM1 ) might be associated with individual differences in opioid sensitivity, as well as with the incidence and severity of postoperative nausea and vomiting (PONV). The goal of the present study was to determine, in a cohort of Japanese surgical patients, genotypes and haplotypes of several SNPs in the OPRM1 gene, and their association with PONV during the early (first 24 h) postoperative period. We examined the incidence and severity of PONV, during the first 24 h after surgery, in 85 Japanese patients receiving intravenous patient-controlled analgesia fentanyl analgesia for postoperative pain control. Eight tag SNPs of the OPRM1 gene (rs1799971, A/G; rs510769, G/A; rs4870266, G/A; rs3798683, G/A; rs1323042, A/C; rs609623, C/T; rs9397685, A/G; and rs644261, C/G) were selected based on their minor allele frequency (>10 %) and linkage disequilibrium strength (10 % in the investigated patients, including GGGAACAC (33 %), AGGGACAC (19 %), GGGAACGC (12 %), and AGAGACAC (10 %). The severity of PONV in carriers of the GGGAACGC haplotype was significantly lower than in the carriers of the other haplotypes ( P