Katayoun Haryalchi - Department of Anesthesiology, Reproductive Health Research Center, Al-Zahra Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
Mandana Mansour Ghanaei - Department of Obstetrics and Gynecology, Reproductive Health Research Center, Alzahra Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
Mohammad Rajabi - Department of Anesthesia, School of Paramedicine, Guilan University of Medical Sciences, Rasht, Iran
Maryam Ghazizadeh - Department of Biostatics, School of Paramedicine, Guilan University of Medical Sciences, Rasht, Iran
Fakhroddin Aghajanpour - Department of Reproductive Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Pouya Koochakpoor - Department of Anesthesia, School of Paramedicine, Guilan University of Medical Sciences, Rasht, Iran
Mahmood Abedinzade - Department of Physiology, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran

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).Methods: ۹۰ Patients were randomly divided to ۳ groups (N=۳۰): ۱- receive oral melatonin (۶ mg), ۲- received pregabalin (۵۰ mg), and third who take 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 ۱,۶,۱۲, and ۲۴ hours after the surgeries. Results: At ۱۲ h 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<۰.۰۵). At ۲۴ h after the TAH, the mean pain intensity in the melatonin group was significantly lower than the third group (P<۰.۰۵). Conclusions: injection preventive melatonin is more effective than pregabalin to reduce pain throughout the first ۲۴ h after the TAH

Hysterectomy, Melatonin, Pain, Pregabalin