Which medications in the drug class Antidiarrheals are used in the treatment of Irritable Bowel Syndrome (IBS)?

Updated: Dec 11, 2019
  • Author: Jenifer K Lehrer, MD; Chief Editor: BS Anand, MD  more...
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These agents are nonabsorbable synthetic opioids. They prolong the GI transit time and decrease secretion via peripheral µ-opioid receptors. They reduce visceral nociception via afferent pathway inhibition.

Diphenoxylate hydrochloride 2.5 mg with atropine sulfate 0.025 mg (Lomotil)

This drug combination consists of 2.5 mg of diphenoxylate, which is a constipating meperidine congener, and 0.025 mg of atropine to discourage abuse. The preparation inhibits excessive GI propulsion and motility, but it may exacerbate constipation.

Loperamide (Imodium)

Loperamide, which is available over the counter, acts on intestinal muscles to inhibit peristalsis and to slow intestinal motility. It prolongs the movement of electrolytes and fluid through the bowel and increases the viscosity and loss of fluids and electrolytes. Loperamide improves stool frequency and consistency, reduces abdominal pain and fecal urgency, and may exacerbate constipation.

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