Abstract

* Loperamide, an antidiarrheal agent available over the counter and also by prescription, may produce serious cardiac effects, including changes in heart rhythm. The risk of adverse effects is more likely if the drug is taken at higher than recommended doses. * Cardiac events such as QT interval prolongation, torsades de pointes, ventricular tachycardia, syncope, and cardiac arrest were documented in 48 case reports evaluated by the Food and Drug Administration. Abnormal cardiac rhythms secondary to loperamide may not respond to typical antiarrhythmic drug therapy.