title: Study of the OPRM1 A118G genetic polymorphism associated with postoperative nausea and vomiting induced by fentanyl intravenous analgesia.
abstract: BACKGROUND
  Genetic polymorphisms of the μ-opioid receptor gene OPRM1 A118G have been shown to influence opioid efficacy. The association of the OPRM1 A118G genetic polymorphism with side effects, such as nausea and vomiting, caused by opioids during analgesia has not been well-represented by the literature . This study aimed to investigate whether the genetic polymorphism of OPRM1 A118G contributed to the variability in nausea and vomiting during fentanyl analgesia in patients undergoing total abdominal hysterectomy or myomectomy.
  
  
  METHODS
  One hundred sixty-five women, of Han nationality, aged 20-50 yrs, of ASA I or II, and scheduled for elective total abdominal hysterectomy or myomectomy under general anesthesia were enrolled. Intravenous fentanyl, patient-controlled analgesia was provided postoperatively for pain control. The presence and scores of postoperative nausea and vomiting for 24 hours were recorded and measured using rating scales. Pain was measured with a visual analog scale, and fentanyl consumption over 24 hours was recorded, as well. Genotyping of the A118G allele was conducted by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and patients were divided into three groups according to their genotype.
  
  
  RESULTS
  The frequency of the A118G allele was 32.4% for the patients in this study. Patients homozygous for 118G required more fentanyl to achieve adequate pain relief compared with the other two patient groups (patients homozygous for 118A and heterozygous). However, there were no statistically significant differences among the frequencies and scores of nausea and vomiting.
  
  
  CONCLUSIONS
  OPRM1 A118G has no effect on the individual variation of postoperative nausea and vomiting, the side effects of fentanyl analgesia, in Chinese women undergoing gynecologic surgery.
authors.affiliation: Department of Anesthesiology, First Affiliated Hospital, Zhengzhou University, Zhengzhou, China.
authors.forename: W
authors.initials: W
authors.lastname: Zhang
authors.forename: J J
authors.initials: JJ
authors.lastname: Yuan
authors.forename: Q C
authors.initials: QC
authors.lastname: Kan
authors.forename: L R
authors.initials: LR
authors.lastname: Zhang
authors.forename: Y Z
authors.initials: YZ
authors.lastname: Chang
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Wang
mesh_terms: D000328:Adult; D019943:Amino Acid Substitution; D016058:Analgesia, Patient-Controlled; D000701:Analgesics, Opioid / Q000009:adverse effects*; D002681:China; D017558:Elective Surgical Procedures; D005006:Ethnicity / Q000235:genetics; D005260:Female; D005283:Fentanyl / Q000009:adverse effects*; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D013509:Gynecologic Surgical Procedures; D006801:Humans; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D020250:Postoperative Nausea and Vomiting / Q000139:chemically induced / Q000235:genetics*; D017450:Receptors, Opioid, mu / Q000235:genetics* / Q000502:physiology; D055815:Young Adult
chemical_list: D000701:Analgesics, Opioid; C485764:OPRM1 protein, human; D017450:Receptors, Opioid, mu; D005283:Fentanyl