Prescription Error: A Case of Metronidazole-Induced Pancreatitis

Introduction: Metronidazole is a nitroimidazole antibacterial drug that is mostly used to treat anaerobic bacteria and protozoa infections. The adverse side effects of metronidazole include gastrointestinal upset, metallic taste, urticaria, headache, peripheral neuropathy. Metronidazole-induced pancreatitis has been rarely described in the literature so far. Objective: We report a rare case of an acute pancreatitis associated with metronidazole which occurred as a result of a prescription error. Methods: This case was reported in February 2022 to The National Centre of Pharmacovigilance and evaluated according to the updated French method of causality assessment. Results: A 70-year-old male patient with a past medical history of chronic viral hepatitis B treated with entecavir since 2006, presented to the surgery department with an acute onset of a severe epigastric pain radiating through to the back associated with hepatic colic with nausea and vomiting. Symptoms started 7 days after initiation of metronidazole given by the patients dentist for treatment of a periodontal abscess. Metronidazole was prescribed twice under two different trade names Birodogyl (spiramycine, metronidazole) and Tamizol(metronidazole) medications. On exam, he had severe epigastric tenderness. Biochemical analysis showed lipase 632 U/L (6N), and amylase 322 U/L (3N). The abdominal CT scan showed an aspect of acute oedemato-interstitial pancreatitis stage B (CSTI 1). Relative negatives in the history included, no lithiasis, no known drug allergies, and no alcohol consumption. Patient symptoms and lipase improved within 3 days after metronidazole withdrawl and initiation of supportive care. Conclusion: The likelihood of metronidazole as the incriminating agent was likely in front of a suggestive delay and favorable outcome after the drug withdrawl. It was suggested a the possible dose-response mechanism between metronidazole use and occurrence of pancreatitis, and this case draw attention to the possible acute pancreatitis associated with metronidazole due to a prescription error.