The aim of this study was to investigate the effect of the μ-
opioid receptor gene (OPRM1) A118G polymorphism on the requirement for post-operative
fentanyl analgesia in patients undergoing radical
gastrectomy. One hundred and twenty-eight
gastric cancer patients scheduled to undergo radical
gastrectomy under
general anesthesia were enrolled in the study. Post-operative, patient-controlled intravenous
analgesia of
fentanyl was provided for satisfactory
analgesia until 48 h after surgery. OPRM1 A118G was screened by DNA sequence analysis of polymerase chain reaction (PCR)-amplified
DNA. Differences in
fentanyl consumption and adverse effects were compared among the different genotypes at 24 and 48 h after surgery. The ranges of
fentanyl dose in the 128 patients at 24 and 48 h after surgery were 5.4-17.3 μg/kg and 12.4-29.9 μg/kg, respectively. Among these patients, there were 54 wild-type homozygotes (AA), 53 heterozygotes (AG) and 21 mutant homozygotes (GG). The frequency of the G allele was 0.371 in the OPRM1 polymorphism. There were no significant differences in
fentanyl dose or adverse effects, including
nausea,
vomiting and
dizziness, for the OPRM1 A118G polymorphism (P>0.05). The OPRM1 A118G polymorphism does not play a significant role in post-operative
fentanyl analgesic dose or post-operative
nausea,
vomiting and
dizziness in patients undergoing radical
gastrectomy.