Antidiarrémedel

Antidiarrémedel are medicines used to treat diarrhea by reducing stool frequency or liquidity. They encompass several classes that act through different mechanisms. Opioid-type agents such as loperamide and, less commonly, diphenoxylate slow intestinal motility by activating μ-opioid receptors in the gut, increasing contact time and absorption of fluids. Bismuth subsalicylate provides antisecretory and mild antimicrobial effects and can ease cramps and nausea. Absorbents and bulk-forming agents (for example kaolin-pectin, attapulgite, polycarbophil) work by binding water and toxins or by increasing stool bulk.

Commonly available over the counter, these medicines are used to relieve acute nonspecific diarrhea and, in some settings, traveler’s diarrhea for symptomatic relief. They may also be used in certain forms of chronic diarrhea, such as irritable bowel syndrome with diarrhea (IBS-D) after evaluation by a clinician. They are not appropriate for all diarrheal illnesses; particularly, they should be avoided when diarrhea is due to an invasive infection or when there is fever, bloody stools, or signs of dehydration, and they should not replace rehydration.

Cautions and adverse effects: loperamide and other opioids can cause constipation, abdominal cramps, dizziness, and rarely ileus; bismuth subsalicylate can darken the tongue and stools and may interact with salicylate-sensitive conditions. They should be used with caution in children, pregnant or breastfeeding women, and in people with inflammatory bowel disease or glaucoma.

Regulatory status varies by country; many agents are available OTC, while some prescriptions combine an antidiarrheal with an antimicrobial or other agent.