Does melatonin addition to indomethacin decrease post endoscopic retrograde cholangiopancreatography pancreatitis? A randomized double-blind controlled trial

Objective Post-ERCP pancreatitis (PEP) is the most prevalent complication of endoscopic retrograde cholangiopancreatography (ERCP). Melatonin has been mentioned as a protective factor against acute pancreatitis. The present study was conducted to determine whether melatonin addition to indomethacin reduces the rate of PEP occurrence. Methods A double-blind randomized clinical trial was conducted on 411 patients undergoing ERCP. Baseline blood samples were collected, and the patients were given melatonin 3 mg tablets plus indomethacin suppository 100 mg or placebo plus indomethacin suppository 100 mg, 1 h before ERCP. The occurrence of PEP was the primary outcome. The concentrations of amylase and lipase were also measured 24 h after ERCP. Results Demographic characteristics of patients, characteristics of ERCP procedures, and baseline levels of amylase and lipase were found to be similar in both groups. The overall rate of PEP was equal to 9.5% in intention-to-treat (ITT) and 11.4% in per-protocol (PP) analyses. There was a significant difference in the rate of PEP between the melatonin and placebo groups (8.7% vs. 11.4% in ITT and 9.3% vs. 13.6% in PP, respectively). In addition, after 24 h, amylase and lipase levels were lower in the melatonin group than in the placebo group ( P = 0.041 and 0.032, respectively). Conclusion The results of the present study showed that, administration of melatonin 3 mg tablets plus indomethacin suppository 100 mg 1 h before ERCP could decrease the PEP rate and amylase and lipase levels compared to administration of indomethacin suppository 100 mg alone.