Loperamide as a Potential Drug of Abuse and Misuse: Fatal Overdoses at the Medical University of South Carolina

Loperamide is an over-the-counter, mu-opioid receptor agonist commonly used as an antidiarrheal agent. Loperamide was thought to have minimal abuse potential due to its low bioavailability and limited central nervous system activity; however, there have been increasing reports of loperamide misuse in supratherapeutic doses to achieve euphoria and/or avoid opioid withdrawal. A literature review suggests a rise in loperamide abuse was inevitable, with substantial increases in reported cases over the last decade. Five fatal cases of toxic medication use where loperamide was listed as a primary or contributory cause of death were identified at the Medical University of South Carolina. The characteristic autopsy demographics and findings are described, and the mechanisms of abuse and toxicity of loperamide are reviewed. Loperamide overdoses are a growing concern from both a forensic and clinical standpoint, and the frequency of reported cases will likely increase as awareness grows within the medical and toxicological communities.