Methadone versus morphine for postoperative pain in patients undergoing surgery for gynecological cancer: A randomized controlled clinical trial

Study objective: The aim of this study was to compare methadone and morphine for the management of post-operative. Design: Open, controlled study. Setting: Postoperative recovering area, ward. Patients: Sixty-four patients, ASA I-III, undergoing gynecological surgery for cancer. Interventions: Morphine or methadone 0.15 mg/kg given preoperatively. After operation an intravenous morphine or intravenous methadone infusion at doses of 12 mg/day was started. Measurements: Pain intensity and opioid consumption. Main results: Methadone infusion provided a better analgesia in comparison with morphine infusion on the second day. Opioid consumption was significantly lower in the methadone group. No episodes of relevant de- saturation or signs of respiratory depression were recorded. Conclusion: A preoperative bolus of methadone, followed by a continuous infusion of low doses post-operatively, provided a better analgesia, without adding risk of adverse effects, in comparison with morphine.