Case Report Metronidazole-Induced Pancreatitis: Is There Underrecognition? A Case Report and Systematic Review of the Literature Ibrahim Youssef, 1 Naba Saeed , 1,2 Mohammad El Abdallah, 2 Kara Huevelhorst, 3 and Kais Zakharia 4 1 Michigan Medicine, University of Michigan, Ann Arbor, Michigan, USA 2 Department of Internal Medicine, Beaumont Health, Dearborn, Michigan, USA 3 Department of Radiology, Beaumont Health–Dearborn, Dearborn, Michigan, USA 4 Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of Iowa, Iowa City, Iowa, USA Correspondence should be addressed to Naba Saeed; naba.saeed@beaumont.org Received 18 March 2019; Accepted 6 May 2019; Published 9 June 2019 Academic Editor: Olga I. Giouleme Copyright © 2019 Ibrahim Youssef et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Introduction. Acute pancreatitis (AP) is the most common cause of gastroenterological hospitalization in the USA, with a mortality ranging from 5 to 20%. Up to 80% of cases are caused by cholelithiasis and alcohol abuse. Less common etiologies that need to be explored include hypertriglyceridemia, trauma, ERCP, infections, and drugs. A number of medications are known to cause acute pancreatitis, with 0.3-1.4% of all cases of pancreatitis being drug induced (DIP). Here, we present a case of metronidazole- induced acute pancreatitis. Case Summary. A 60-year-old female presented with constant severe epigastric pain associated with nausea, vomiting, and anorexia for one day. She had no past medical history of alcohol use or hypertriglyceridemia and was s/p cholecystectomy in the distant past. Symptoms had begun three days afer starting metronidazole for Clostridium difcile colitis. Lipase was > 396, and CT abdomen revealed peripancreatic fat stranding. She was diagnosed with AP, metronidazole was suspected to be responsible and hence stopped, and supportive management initiated. Her symptoms improved rapidly, and pancreatic enzymes normalized within 2 days. Of note, she had had an episode of acute pancreatitis 3 years ago, also following metronidazole use, with resolution at discontinuation of the drug. She had concurrently been on omeprazole during both episodes. Discussion. Metronidazole is a commonly used antibiotic and is infrequently reported as a cause of DIP. Our review suggests the possibility of a dose-response and duration-response efect between metronidazole use and occurrence of pancreatitis. Te most common presenting symptom and sign was moderate to severe epigastric pain and tenderness, accompanied by nausea/vomiting. Symptoms usually start within 2-7 days of starting the medication and usually resolve 2-5 days afer discontinuation of therapy and pancreatitis treatment. Te most common causative dose was 1-1.5 g/day. Our review also supports fndings by Norgaard et al. suggesting that concurrent use of omeprazole potentiates the risk of metronidazole-induced pancreatitis. Conclusion. Metronidazole is a commonly used antibiotic that may cause metronidazole-induced pancreatitis, especially if patients are concurrently taking PPIs. Awareness needs to be raised amongst clinicians regarding this association, in order to correctly identify etiology of pancreatitis and discontinue metronidazole promptly when suspected as the causative factor. 1. Introduction Acute pancreatitis (AP) is the most common cause of gas- trointestinal hospitalizations in the United States with increasing incidence and costs [1]. Its mortality rate ranges from 5 to 20% depending on the severity of the disease [2]. Te most common symptom of pancreatitis is epigastric pain, sometimes radiating to the back, with nausea and vomiting [3]. Atlanta criteria for the diagnosis of AP require two of three of the following: (1) characteristic epigastric abdominal pain, (2) at least three times elevation of serum amylase and/or lipase, and (3) characteristic fndings on imaging studies [4]. Gallstones and alcohol abuse are the most common causes of acute pancreatitis accounting for 70-80% of all cases [5]. Other less common etiologies include hyper- triglyceridemia, ERCP, hypercalcemia, trauma, infections, Hindawi Case Reports in Gastrointestinal Medicine Volume 2019, Article ID 4840539, 6 pages https://doi.org/10.1155/2019/4840539