Medical examiners believe an overdose of loperamide, which is often marketed under brands like Imodium to treat diarrhea, is the cause of the death of a Pennsylvania man recently in a stunning and alarming development. Arjun Patel, 29, died in November, and a subsequent autopsy indicates that it was loperamide poisoning that was the cause, reports news station KDKA.

Loperamide is sold over the counter and is meant for treating diarrhea. Most people do not realize that the drug can be dangerous if taken in excess. It is recommended that dosage should not exceed 8 milligrams per day, although prescriptions of lopoeramide can be up to 16 mg per day.

It is a stark reminder that even over the counter medications can be fatal is consumed in excess. Other common drugs that can be purchased at your local pharmacy can be dangerous – like Tylenol, for example, which can cause liver failure if dosage instructions are not followed.

“To foster safe use of the over-the counter (OTC) anti-diarrhea drug loperamide, FDA is working with manufacturers to use blister packs or other single dose packaging and to limit the number of doses in a package,” reads an FDA statement on loperamide. “FDA continues to receive reports of serious heart problems and deaths with much higher than the recommended doses of loperamide, primarily among people who are intentionally misusing or abusing the product, despite the addition of a warning to the medicine label and a previous communication. Loperamide is a safe drug when used as directed.”