Evaluation of melatonin effect on pelvic pain in women with endometriosis referred to affiliated hospitals to Tehran Medical Sciences of Islamic Azad University

Endometriosis is an estrogen dependent disease that causes endometriosis associated chronic pelvic pain (EACCP) in women with endometriosis via severe inflammatory reactions. Melatonin, as an antioxidant analgesic agent, seems to play a significant role in pain relief in endometriosis. This research was performed to investigate the efficacy of Melatonin on pelvic pain relief in women with endometriosis. In this randomized triple-blind trial, 40 women with EACCP score≥7 participated in the study. The participants were randomized into melatonin and control groups. Melatonin group (n=20) received 5 mg melatonin for 8weeks. Control group (n=20) received placebo with the same characteristics as melatonin for the same duration. Pain score was recorded before treatment, and at the end of both the first and the second 4-week periods. Data were analyzed with SPSS.ver22. There was no statistically significant difference in dysmenorrhea pain score between control and treatment groups, at the beginning of study; while after 8weeks, pain score were significant different between control (5.86±0.99) and treatment groups (3.95±1.57). There was no statistically significant difference in EACCP score, at the beginning, between control and treatment groups. After 8weeks, pain score was significantly higher in control group (5.57±1.02) compared to treatment group (3.57±1.60). Moreover, highly significant reduction in analgesic agents’ consumption was observed in treatment group compared to control group. Regarding results, it is concluded that melatonin in comparison with placebo, considerably alleviates EACCP and dysmenorrhea, and reduces analgesic agents’ consumption.