Background: Postoperative pain is a common side effect following surgery that can significantly reduce surgical quality and patient’s satisfaction. Treatment options are morphine and buprenorphine. We aimed to compare the efficacy of a single dose of intravenous morphine with sublingual buprenorphine in postoperative pain control following closed reduction surgery. Methods: This triple blind clinical trial was conducted on ۹۰ patients referred for closed reduction orthopedic surgery. They were older than ۱۸ years and in classes I and II of the American Society of Anesthesiologists (ASA) with an operation time of ۳۰-۹۰ minutes. Patients were divided into two groups of buprenorphine (۴.۵μg/kg sublingually) and morphine (۰.۲mg/kg intravenously). Baseline characteristics, vital signs, pain score, level of sedation and pharmacological side effects were recorded in the recovery room (at ۰ and ۳۰ minutes), and in the ward (at ۳, ۶ and ۱۲ hours). SPSS version ۱۹ software was used for data analysis and the significance level was set at P Results: Ninety patients were studied, ۶۰ males and ۳۰ females with a mean age of ۳۷.۷±۱۶.۲ years. There was no significant difference between the two groups in terms of baseline characteristics.Pain score in the morphine group was significantly higher than the buprenorphine group with an average score of ۲.۵ (P<۰.۰۰۱). Postoperative mean heart rate in the buprenorphine group was four beats lower than the morphine group (P<۰.۰۰۱). Also, in the buprenorphine ۴۸.۶% and in the morphine group ۸۶.۷% of cases were conscious in recovery (P=۰.۰۰۱) with a higher rate of pruritus in the latter group (P=۰.۰۰۱). Conclusion:
Sublingual buprenorphine administration before anesthesia induction in closed reduction surgery can lead to better postoperative pain control in comparison to intravenous morphine. Due to simple usage and longer postoperative sedation, sublingual buprenorphine is recommended as a suitable drug in closed reduction surgery.