Intentional Misuse and Abuse of Loperamide: A New Look at a Drug with "Low Abuse Potential".

BACKGROUND: Despite its opioid properties, loperamide has long been thought to have low abuse potential due to its poor absorption from the gastrointestinal tract and limited potential to cross the blood-brain barrier. A recent patient reportedly taking loperamide to avoid heroin withdrawal symptoms, at doses approximately 100 times those recommended, directed our attention to this issue.

OBJECTIVES: 1) Investigate number of cases of intentional loperamide abuse and misuse reported to poison centers between 2009 and 2015; 2) Compile reports of clinical effects of loperamide abuse; and 3) Search for evidence of increasing Internet interest in the central opioid effects of loperamide.

METHODS: For the years 2009 thru 2015, we reviewed exposure calls related to misuse/abuse of loperamide in the Texas Poison Center Network's database and the National Poison Data System. We used Google trend analysis to detect evidence of increased Internet interest in the illicit use of loperamide.

RESULTS: Between 2009 and 2015, the number of misuse/abuse calls related to loperamide alone nearly doubled, with about one-third of cases occurring in teens and young adults in their 20s. Of particular concern are reports of significant cardiotoxic effects (∼18% of cases), including conduction defects and various dysrhythmias, sometimes leading to death. Google Trends analysis demonstrates an increasing number of searches for "loperamide high" and "loperamide withdrawal" beginning in 2011.

CONCLUSIONS: Loperamide misuse/abuse seems to be on the rise. Given its propensity to induce conduction disturbances and dysrhythmias at very high doses, emergency physicians should be vigilant for this form of drug abuse.