Loperamide: an emerging drug of abuse and cause of prolonged QTc.

Loperamide is an over-the-counter medication which is commonly used to treat diarrhoea. In excessive doses, loperamide acts as an opioid on the central nervous system, which contributes to its increasing popularity as an alternative substance for opiate addictions. High doses for prolonged periods can cause prolonged QTc and provoke life-threatening arrhythmias, such as ventricular fibrillation. We report the case of a young female who developed dangerous arrhythmias as a result of chronic loperamide overdosing. Following syncopal episodes at rest, she was admitted for a period of monitored observation and later discharged with a plan to taper her loperamide in the community. Upon second presentation, her loperamide was replaced with buprenorphine patches, which were then weaned successfully in the community. Despite this, she passed away several months later, most likely from an underlying congenital cardiac arrhythmia which was unmasked by excessive use of loperamide. © Royal College of Physicians 2021. All rights reserved.