Comparison of the Effects of Methadone and Morphine on Postoperative Pain Scale following Thoracic Surgery in Opium Addict Patients

Background & Aims: Post operative pain is cause of suffering in most patients and can cause a lot of problems. Analgesic effects of many narcotics have been widely studied. In this study, the effects of methadone and morphine on postoperative pain scale following thoracic surgery in opium addict patients were assessed. Methods: In this clinical trial and double blind study, sixty opium addict patients (ASA I, II), aged 20-65 yr, were randomly allocated into two groups. Thirty minutes before induction of general anesthesia the first group received 0.1 mg/kg methadone and the second group received 0.1 mg/kg morphine. The two groups were assessed and compared in regard to the intensity of pain and meperidine requirement in the first post operative 24 hr. Results: Intensity of post operative pain and meperidine requirement in the methadone group were significantly lower than those in the morphine group (P<0.01). Conclusion: Administration of 0.1mg/kg methadone as premedication for opium addict patients reduces the post operative pain more than morphine. Therefore, premedication with methadone for opium addict patients undergoing thoracic surgery is recommended.