preventive dose of melatonin on postoperative pain in total abdominal hysterectomy: a clinical trial study

Background & objective: studies have shown contradictory results regarding the use of pregabalin and melatonin as analgesic agents. because the analgesic effects of these drugs as preemptive have not been compared in abdominal hysterectomy, one of the most common surgical procedures in women with moderate to severe pain, under general anesthesia. the aim of this study was to compare the pretreatment effects of melatonin and pregabalin on postoperative pain intensity in total abdominal hysterectomy (tah). materials & methods: ninety patients were randomly divided into three groups (n=30): the first group received oral melatonin (6 mg), the second group received pregabalin (50 mg), and the third one who took no drug. serum melatonin and beta-endorphin levels were measured before and after the surgery. pain intensity was assessed by the numerical rating scale at 1,6,12, and 24 hours after the surgeries. results: at 12 hrs after the surgery, mean pain intensity in the melatonin group was significantly lower than the pregabalin group, and in the pregabalin group was significantly lower than the third group (p<0.05). at 24 hrs after the tah, the mean pain intensity in the melatonin group was significantly lower than the third group (p<0.05). conclusion: injection preventive melatonin is more effective than pregabalin to reduce pain throughout the first 24 hrs after the tah.