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Ammara Khan
Akbar Waheed
Ayesha Afzal
Ajmal Afzal
Zahid Azam Chaudry
Syed Ihtisham Haider
Shafia Arshad


OPRM1, rs1799971, Postoperative Pain, Tramadol, Efficacy, Safety, Genotypes, Pakistani Population, Personalized Medicine


Objective: This pioneering study aims to understand the influence of genetic polymorphism identified as rs1799971 in the exon 1 of mu-opioid receptor (OPRM1) gene on the safety and efficacy of tramadol in context to postoperative pain within Pakistani population. Insights from this research may contribute to more tailored approaches to pain management in this demographic.

Study Design: Uncontrolled Cohort Pharmacogenetics Studies

Place & duration of study: Nawaz Sharif Medical College, Gujrat from March 2022- December 2022

Methods: This study was conducted within Gujrat city population in Punjab, Pakistan. Participants were genotyped for the OPRM1 (rs1799971) SNP (AA, AG, GG) using Sanger sequencing technique. Postoperative pain scores, rescue analgesic requirements, and side effects such as nausea, vomiting, and sedation were assessed at multiple time points within 24 hours post-surgery among the three OPRM1 genotypes. The data were analyzed using IBM SPSS Statistics 26, comparing pain scores and categorical variables like sedation and nausea amongst different genotypes, considering a p-value of 0.05 or less as statistically significant.

Results: The variant allele “G” was observed in 31.5% of study population with GG genotype in 11% of our study population, adhering to Hardy-Weinberg equilibrium. Patients with GG genotype reported statistically higher pain scores both at rest and on movement (<0.001 vs AA) and required more rescue analgesia in the immediate postoperative phase. However, they experienced fewer incidents of nausea, vomiting, and sedation within the initial post-surgery hours. Similarly other tramadol induced side effects were minimally observed in this set of patients.

Conclusion: This study underscores the significant influence of OPRM1(rs1799971) genotypes on efficacy and safety of  tramadol in acute pain settings within the Pakistani population paving way for personalized analgesic strategies to optimize patient results


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