A 39-year-old man with a history of opioid addiction suddenly gasped for breath and collapsed in his home.

The responding emergency team began CPR, which they continued on the way to the hospital. But by the time they arrived, it was too late.

The man was pronounced dead in the emergency room.

This case report, published online April 29 in the Annals of Emergency Medicine, might be just another incident among the thousands of deaths in the United States each year related to prescription opioids.

Except for one small detail.

The man had been self-treating his opioid addiction for around three years using loperamide — an anti-diarrheal drug sold over the counter as Johnson & Johnson’s Imodium or Medique’s Diamode.

An autopsy revealed that the level of loperamide in the man’s blood was almost 50 times what would be found from a recommended dose of the medication.

Reports like this have raised concerns among some doctors that people addicted to opioids may be turning to loperamide to manage their opioid withdrawal symptoms or achieve euphoria.

“Loperamide's accessibility, low cost, over-the-counter legal status, and lack of social stigma all contribute to its potential for abuse,” lead study author William Eggleston, Pharm.D., of the Upstate New York Poison Center, in Syracuse, New York, said in a press release.

Read More: Prescription Drugs Lead to Heroin Addiction »

Abuse at High Doses

Loperamide is an opioid, like the active ingredient in the pain medications OxyContin, Vicodin, and Percocet.

But unlike those three drugs, loperamide targets opioid receptors in the gut, not the brain. That’s because loperamide has a hard time getting past the blood-brain barrier.

The Food and Drug Administration (FDA) approved loperamide in the 1970s. Early pharmacological trials — including a 1980 study in the journal Clinical Pharmacology and Therapeutics — found that the drug “poses little threat of potential abuse.”

The Centers for Disease Control and Prevention (CDC) even recommends Imodium for people who develop diarrhea while traveling abroad.

With a rise in the number of Americans addicted to opioids in recent years, loperamide’s reputation went from low risk of abuse to a “poor man’s methadone.”

A 2013 study in the journal Drug and Alcohol Dependence found an increase in the number of people posting on an online drug forum about how to use loperamide recreationally.

People were recommending using doses of 70 to 100 mg of loperamide per day. The maximum dose recommended for relief from diarrhea is 16 mg a day.

Some people may be using even higher amounts. A report in the journal BMJ Case Reports mentions a 26-year-old man who had been taking 800 mg of loperamide a day.

Posts on drug forums suggest that many people consume high doses of the anti-diarrheal pills orally. But some may be crushing the pills and smoking the powder with marijuana. Others even suggest injecting it in a liquid form.

At recommended doses, loperamide is safe to use for treatment of diarrhea. But at high levels typical of abuse, it can depress breathing and the nervous system, disrupt the heartbeat, and even cause death.

Read More: Elder Drug Abuse is on the Rise »

Doctors Call for Regulation

As shocking as some of the case reports are, it’s difficult to know the exact extent of the problem.

However, data from poison control centers “suggest that misuse and abuse of loperamide is a growing problem nationally,” said Eggleston in an email to Healthline.

At the Upstate New York Poison Center, Eggleston and his colleagues saw a seven-fold increase in calls about loperamide abuse or misuse between 2011 and 2015.

This echoes data from national poison centers, which showed a 71 percent increase in intentional misuse of loperamide between 2011 and 2014.

“I think these numbers are likely an under-representation of actual loperamide abuse nationwide,” said Eggleston.

The available data is dramatic enough that Eggleston and his colleagues are calling for sales of loperamide to be regulated, similar to some over-the-counter medications used to alleviate nasal and sinus congestion.

In many states, these allergy, cold, and sinus medicines contain pseudoephedrine, so they can only be sold in limited quantities. Oregon now requires a prescription for these products, which can be used to make methamphetamine.

Some states also prohibit the sale of over-the-counter medicines containing dextromethorphan to minors.

These types of regulations would allow access to loperamide to patients who want to use it safely but prevent sales of it in bulk.

Past laws have seen some success in reducing abuse of these medications.

“Indications are that passage of all these state laws and regulations resulted in sharp drops in domestic methamphetamine production across the country,” Sarah Kelsey, chief executive officer of the nonprofit National Alliance for Model State Drug Laws (NAMSDL), said in an email to Healthline.

Better monitoring of the abuse of over-the-counter medications is also needed. This includes reporting to the FDA’s MedWatch.

“We are urging the public and healthcare providers to report abuse so that we can get a better sense of the true extent of this issue,” said Eggleston.

Read More: Emergency Rooms Running Short on Some Medications »