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.