Loperamide-Induced Pancreatitis: Report of Three Cases

Background: Only 0.1-2% of acute pancreatitis seems to be drug-induced, being this etiology probably underestimated and often classified as idiopathic. Loperamide is an opiate with peripheral action, used in the treatment of diarrhea. Since 2012 it belongs to the FDA list of drugs potentially able to cause acute pancreatitis, because of its capacity of modulating the secretion from the exocrine pancreas and of causing sphincter of Oddi dysfunction.Case presentation: We report the cases of three women, admitted to our hospital for acute pancreatitis. In their medical history two of them referred remote cholecystectomy. They all reported recent loperamide intake, given to acute diarrhea, denying alcohol consumption, smoking or family history for pancreatic disease. During the hospitalization laboratory tests showed increase of pancreatic enzyme and liver function alteration, with a rapid clinical improvement after loperamide suspension. Pancreatic Magnetic Resonance Imaging (MRI), including MR cholangiopancreatography, was performed in all the cases, showing a well-defined pancreatic gland without any sign of acute inflammation and excluding common bile duct lithiasis. Given the absence of common risk factors and the temporal correlation between drug intake and occurrence of symptoms, we considered loperamide responsible of these three cases of acute pancreatitis.Conclusion: In patients with acute pancreatitis, referring recent loperamide intake, in the absence of any other causes, iatrogenic damage must be considered as a possible etiologic factor.