The over-the-counter medication Imodium, whose main ingredient, loperamide, is an opioid, is cheap and easy to buy at a drugstore. It's available in bulk at Walmart and Costco.
"Drug users, opioid seekers, they are desperate," says Nardine Nakhla, a lecturer at the faculty of pharmacy at the University of Toronto.
"They need this medication to help with the withdrawal, or to achieve that euphoric state. So they disregard the warning and still use the drug if it means they get their fix."
Imodium is safe when taken as directed. The maximum recommended daily dose is 16 milligrams, or eight tablets.
"It's been likened to a poor man's methadone", says Dr. David Juurlink, a drug safety researcher at Sunnybrook Hospital. "At high doses, it will cause effects like methadone or oxycontin. The problem is the doses you need to achieve that is really, really dangerous."
Juurlink says its not uncommon for drug abusers to take up to 200 tablets a day to get high.
"It can cause your heart to stop. It's the sort of thing people can do for weeks or months at a time, with no symptoms at all, then suddenly they just drop dead," says Juurlink.
He says people abusing this drug will put a few hundred pills in a blender, make a smoothie and drink it. "That's especially dangerous because you absorb the drug very quickly."
'Poor man's methadone': Imodium is a potentially fatal high - Health - CBC News