Loperamide is an antidiarrheal active ingredient available in over-the-counter (OTC) medicines that treat the symptoms of diarrhea, including traveler’s diarrhea. It may be written as loperamide or loperamide hydrochloride (HCl), but it is the same ingredient. Loperamide can be the only active ingredient in an anti-diarrheal medicine or it can be found in medicines that also treat symptoms such as gas. Loperamide is also available as a prescription product with a maximum approved dose of 16 mg per day.
Loperamide is approved by the U.S. Food and Drug Administration (FDA) and is safe and effective when used according to the Drug Facts label. Taking higher than recommended doses of loperamide can cause severe heart rhythm problems or death. Certain medications can also increase blood levels of loperamide and cause serious heart problems.
Seek immediate medical attention if you or someone taking loperamide experiences any of the following: fainting, rapid heartbeat or irregular heart rhythm, or unresponsiveness (meaning that you can’t wake the person up or the person doesn’t answer or react normally). If you develop abdominal swelling or bulging, or if your diarrhea lasts for more than two days while taking an OTC medicine containing loperamide, contact your healthcare provider. These may be signs of a more serious condition.