Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 50 6 2012 06 15 395 398 EN Mohammad Hassan Abdollahi Yazd Cardiovascular Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Seyed Khalil Forouzannia School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Mostafa Bagherinasab Yazd Cardiovascular Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Kazem Barzegar School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Asefeh Fekri Yazd Cardiovascular Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Mohammadtaghi Sarebanhassanabadi Yazd Cardiovascular Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Ahmad Entezari Yazd Cardiovascular Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. 2015 09 28 One of the most common complications of operation and anesthesia is shivering. The purpose of this study was to compare the effectiveness of Ondanseton and Meperedine in preventing shivering after offpump coronary artery bypass graft (OPCAB). In this double-blind randomized clinical trial, the sample consisted of 90 patients, who were candidates of CABG under general anesthesia. These patients were assigned to three groups, each containing 30 subjects: meperedine group (A), ondansetron group (B) and control group (C). Group (A) received 0.4 mg/Kg/IV of meperedine, group (B) received 8mg/IV of ondansetron and group (C) received Normal Saline. All these drugs were injected 15 minutes before the end of surgery. After the end of surgery, the intubated patients were transferred to the ICU and their body temperature was assessed through eardrum by a specialist who was blind to the research. The incidence of shivering in groups A, B, and C was 46.48%, 31.18%, and 60.83%, respectively (P=<0.01). The incidence of shivering was 64.4% in males and 35.6% in females (P=0.222). Also, the amount of incidence of shivering up to 3 hours after surgery was 75.87 % (P=0.064). Bradycardia was 3.3% in group (A) and 0.0 % in group (B). Other variables (myoclonus, seizure and rash) showed no statistically significant difference (P=0.353). According to the findings, it was demonstrated that ondansetron is more effective in preventing shivering after Off-pump CABG than meperedine. https://acta.tums.ac.ir/index.php/acta/article/view/3919 https://acta.tums.ac.ir/index.php/acta/article/download/3919/3894