Last year in Pittsburgh, a 29-year-old man died from loperamide poisoning, and officials are warning of a huge spike in Imodium overdose cases.
Loperamide, sold under brand names such as Imodium, is a mu opioid receptor agonist, meaning it can saturate the mu receptors in the brain responsible for quelling pain. It acts similarly to morphine it its analgesic effect, and in one study by Ray et al, it worked better than morphine.
Why is loperamide, then, used for diarrhea?
Loperamide slows down the motility of the gut by acting on the smooth muscle lining in the intestine. Food as it transports down the colon is stripped of much of its water content prior to being expelled as feces. However in those with diarrhea, the transit time is much shorter and the body does not have a chance to remove the water. Slowing this pathway down, with loperamide, changes the consistency of the stool and the frequency of stools.
Earlier this year two British citizens died of Imodium overdose and officials are concerned many more non fatal overdoses may be occurring daily.
Loperamide is easy to obtain
First synthesized in the 1960’s, loperamde joined the pharmaceutical industry officially in 1976 when the FDA approved its brand named form, Imodium. Although first introduced as a prescription, Imodium became a widely popular over-the-counter (OTC) remedy by the 1980’s. Still popular, it remains an OTC, easy to purchase, treatment for diarrhea stocked ubiquitously in stores.
How much Loperamide is too much?
According to drugs.com, dosing is:
4 mg orally after the first loose stool, then 2 mg orally after each unformed stool
Maximum dose: 16 mg per day
However, overdoses can occur based on weight, metabolism and if other medications are being used simultaneously that can interfere with the drug’s bioavailability. Moreover if one is currently taking narcotics for pain, this could synergistically increase one’s levels of the drug.
What are the side effects of Loperamide?
Regular use of the agent can cause:
- dry mouth
- abdominal pain
In training we learned that if one was suffering from an intestinal pathogen resulting in diarrhea, using loperamide could lengthen the course of the illness as the flushing mechanism during diarrhea is now inhibited.
How can Loperamide kill one using it?
Uniquely, loperamide can cause dangerous heart arrhythmias such as Torsades de points, which can lead to cardiac arrest and death.
So why is Loperamide still used and easily available?
Diarrhea and hyper gut motility cause millions of Americans each year discomfort, time off work and embarrassment. Moreover, diarrhea can acutely cause dehydration and medicines such as Imodium are widely used in the health care setting for this reason.
But its pharmacological similarity to opiates allows it to be one of the easiest drugs to obtain and abuse. And with political pressure to decrease access to prescription narcotics becoming more successful, coupled with narcotic withdrawal being so painful and traumatizing, we anticipate more individuals hastily and non-responsibly seeking relief with medications such as Loperamide.
Daliah Wachs, MD, FAAFP is a nationally syndicated radio personality on GCN Network, iHeart Radio and Board Certified Family Physician