The Effect of Opioid Receptor Gene Polymorphism (A118G) on Tramadol Consumption After Caesarean Section
Mehmet Mutlu1, Huseyin Sen21Department of Anesthesiology and Reanimation, Okmeydani Training and Research Hospital, 2Department of Anesthesiology and Reanimation, University of Health Sciences, Istanbul, Turkey
Objectives: The efficacy of opioid analgesics is related to the µ-opioid receptor gene. The aim of this study was to determine the frequency of opioid receptor gene polymorphism at position 118 and response to tramadol for postcesarean analgesia. Methods We recruited 100 patients aged between 18–45 years, who could use patient-controlled analgesia (PCA) device and express their pain severity with visual rating scale (VRS), and had ASA I-II, undergoing cesarean section under spinal anesthesia. Blood samples were genotyped for the A118G polymorphism-A118 homozygous (AA), heterozygous (AG), or homozygous for the G allele (GG). Pain scores, the severity of nausea and vomiting, other complicaitons and the total self-administered intravenous tramadol consumption were recorded for the first 24 postoperative hours. Results Among the 100 patients in the study, 77 (77%) had a genotype of homozygous 118AA (AA normal), 19 (19%) were heterozygous 118AG (AG), and the remaining four (4%) were genotype homozygous 118GG (GG mutant type). The patients were divided into 3 groups. Compared to that in patients with AG genotype, those with AA homozygous genotype had significantly higher time to the first analgesic, lower dose of total additional analgesic, and higher patient satisfaction scores. Nausea and vomiting scores of patients with GG homozygous genotype were significantly higher. Conclusýon In conclusion, A118G polymorphism is associated with variations in tramadol consumption and pain scores. The relative rare frequency of the patients who have 118GG homozygous gene within the Turkish population implies that it could be safe to use tramadol for postoperative analgesia. Keywords Opioid analgesics, µ-opioid receptor gene, tramadol
Cite This Article
Mutlu M, Sen H. The Effect of Opioid Receptor Gene Polymorphism (A118G) on Tramadol Consumption After Caesarean Section. EJMI. 2020; 4(4): 520-524
Corresponding Author: Mehmet Mutlu