Effect of Magnesium Sulfate Added to Tincture of Opium and Buprenorphine on Pain and Quality of Life in Women with Dysmenorrhea: A Prospective, Randomized, Double-blind, Placebo-controlled Trial

BACKGROUND: Adding magnesium sulfate (MgSO4) to opioid receptor agonists increases the opioid analgesic effects via blocking this receptor. The current study aimed to evaluate the effectiveness of adding MgSO4 to tincture of opium (TOP) and buprenorphine (BUP) on pain and quality of life (QOL). METHODS: In prospective, randomized, double-blind, placebo-controlled clinical trial, one hundred and sixty-three women with secondary dysmenorrhea caused by endometriosis were selected using a respondent-driven sampling (RDS) and assigned into six groups using block randomization. Patients received 50 mg/kg MgSO4 in 100 ml saline by micro set in six monthly menstrual periods and completed the visual analogue scale (VAS) and QOL Questionnaire (QOLQ). Data were analyzed by repeated measures analysis of variance (ANOVA) and hierarchical regression. FINDINGS: The primary outcomes showed that pain scores in magnesium (MAG) + opium tincture (OT) [F = 5.7(1,162), P = 0.004] and MAG+ BUP [F = 4.5(1,162), P = 0.006] groups showed a significant decrease compared with control group. Also, QOL scores in MAG + OT [F = 4.8(1,162), P = 0.005] and MAG + BUP [F = 5.9(1,162), P = 0.003] showed a significant increase. However, there was no significant difference between the two groups (P = 0.140) and the changes did not persist until follow-up (P = 0.810). Secondary outcomes indicated that the low scores of the two components of QOL including physical and psychological components were predictors of pain (P = 0.011, Beta > 3.09). CONCLUSION: Simultaneous use of MAG with opioids is associated with pain reduction and the improvement of QOL. However, this hypothesis requires careful handling in a randomized controlled trial.