Non-steroidal anti-inflammatory drugs for the prevention of post-endoscopic retrograde cholangiography pancreatitis Short title: Post-ERCP pancreatitis prevention

Background: Post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP) is a serious disease. The role of nonsteroidal anti-inflammatory drugs (NSAIDs) in the prevention of PEP is conflicting. Objectives: This review aimed to assess the preventive role of NSAIDs in PEP with special emphasis on the dose and route of administration. Methods: We searched PubMed and Google Scholar for relevant observational studies published in English during the period from January 2010 to January 2020. The terms post-ERCP pancreatitis, diclofenac sodium, indomethacin, NSAIDs, dose, route of administration were used. Results: Of the 179 identified, 19 full texts were screened and included in the review. Ten studies were from Europe, seven from Asia and two were published in the USA, the studies showed that NSAIDs were effective in preventing PEP when used rectally or intramuscularly, higher doses are more efficacious and the combination with stents was not superior, careful patients selection is needed in particular regarding the body mass index. Conclusion: NSAIDs were effective in PEP prevention; however, the evidence is weak due to the observational nature and the different methods used in the included studies. Randomized controlled studies are needed to solve the issue.