Loperamide
Opioid agonist used to treat diarrhea by slowing intestinal contractions.
Loperamide, sold under the brand name Imodium among others, is a medication of the opioid receptor agonist class used to decrease the frequency of diarrhea. It is often used for this purpose in irritable bowel syndrome, inflammatory bowel disease, short bowel syndrome, Crohn's disease, and ulcerative colitis. Loperamide is taken by mouth.
- drug_class
- opioid receptor agonist
- common_brand
- Imodium
- route
- oral
- who_essential_medicine
- True
Lore & Background
During the 1980s, Imodium became the best-selling prescription antidiarrheal in the United States.
Reader's Guide
Loperamide is significant as a widely used antidiarrheal medication that acts on μ-opioid receptors in the intestine without significant central nervous system effects at normal doses, due to limited absorption and P-glycoprotein efflux preventing blood-brain barrier crossing. Its legacy includes being on the World Health Organization's List of Essential Medicines and being available as a generic medication. However, its use requires caution: it is contraindicated in cases of high fever, bloody stool, or suspected infections with organisms that can penetrate intestinal walls, and in children under three years of age. High doses can overcome the blood-brain barrier and produce euphoric effects or heart problems. Loperamide remains a first-line treatment for various types of diarrhea, but its safety in pregnancy is unclear, and it is not recommended for nursing mothers in the UK.
Did You Know?
- High doses of loperamide (>70 mg) can saturate P-glycoprotein and cross the blood-brain barrier, potentially producing euphoric effects.
- Loperamide is on the World Health Organization's List of Essential Medicines.
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