OTC Safety

Maria G. Tanzi, PharmD

Loperamide misuse and abuse is on the rise with some individuals consuming high doses in an attempt to self-manage their opioid withdrawal symptoms or to achieve a euphoric high. The issue has become so pervasive and problematic in recent years that some have labeled loperamide the “poor man’s methadone.”

“Abuse of loperamide continues in the United States, and taking higher than recommended doses can cause serious heart problems that can lead to death,” said FDA in a news article when new packaging for OTC loperamide products was announced in September 2019. The changes to Imodium A-D, Imodium Multi-Symptom Relief, and Be Health Loperamide HCl Capsules were intended to address the problem of loperamide abuse and misuse by limiting each carton to no more than 48 mg of loperamide and requiring unit-dose blister packaging.

Provider, patient education

Pharmacists should be aware of the potential for loperamide abuse so they can educate patients on the safe and effective use of this medication.

The Consumer Healthcare Products Association (CHPA) has an entire webpage dedicated to loperamide safety (www.loperamidesafety.org/). It includes numerous resources for health care providers, including a fact sheet for pharmacists.

Even though there are currently no treatment protocols to manage loperamide abuse, providers should consider the potential for this type of abuse when a patient presents with unexplained cardiotoxicity (see below). Since loperamide will not appear in a standard toxicology screen and there is no urine test to detect its presence, providers should be encouraged to ask patients specific questions, including

Have you been using loperamide?

How much loperamide do you take and how often?

Are you aware of the severe heart risks associated with overuse, misuse, and abuse of loperamide?

Providers can educate patients about the appropriate dosing of loperamide by reviewing the Drug Facts label on the OTC product. CHPA notes that providers should be cautious in how they share the information with patients, however, since it is important to not inadvertently inform someone of loperamide abuse who may be at risk for misuse or abuse. Educate patients who report using higher than approved doses of loperamide about the serious risks and refer them to an appropriate source of treatment, if possible. Also, report exposures to Poison Control or FDA’s MedWatch.

Case reports

Loperamide is a potent µ-opioid receptor agonist and is sold OTC to treat symptoms of diarrhea. When used as directed (i.e., maximum approved daily dose for adults is 8 mg per day of OTC loperamide and 16 mg per day for prescription use), the product is considered safe and effective.

However, abuse of this product at supratherapeutic doses has resulted in increasing reports of serious heart problems and deaths.

 At labeled doses, the drug has a large safety margin, but at excessive doses, loperamide can inhibit the potassium channels and cardiac sodium channels, which can result in QT and QRS prolongation and induce arrhythmias. It has been reported that users seeking an opioid-like high take loperamide in excess of 100 mg per dose.

Fatal overdoses of loperamide have been documented, such as 5 patients from the University of South Carolina (J Forensic Sci. 2019;64(6):1726-30); 21 cases from North Carolina (J Anal Toxicol. 2016;40(8):677-86); and 8 cases from Alabama (J Anal Toxicol. 2017;41(9):729-34). Most of these patients were white men in their thirties, and most cases were part of a mixed drug overdose.

Signs of loperamide abuse or toxicity

• Syncope or fainting
• Rapid or irregular heartbeat
• Unresponsiveness
• QT interval prolongation
• Torsades de pointes
• Ventricular arrhythmias
• Cardiac arrest
• GI complications (e.g., nausea, vomiting, constipation, and paralyzed intestine)

Source: www.loperamidesafety.org/resources