Antidiarrheals – Mechanism of action, Indications, Contraindication, Adverse effects and Drug interactions


Drug used to control diarrhoea is called antidiarrheal

Mechanism of action

Antidiarrheals active opioids receptor in G.I. tract to decrease
intestinal motility and to increase the absorption of fluid and sodium in the

Drug example and doses

1 Loperamide – 2-4mg

2 Diphenoxylate – 5-10mg

3 Octreotide – 100-250mcg/TID

4 Polycarbophil

5 Bismuth subsalicylate – 60 ml 6hourly suspension

Indications / Uses

To treat underlying cause of diarrhea.

To control the relive symptoms of acute and chronic diarrhea.

Contraindication / Precautions

Contraindicated in abdominal pain of unknown pathology.

There is an increased risk of megacolon in clients with
inflammatory bowel disorders.

This could lead to a serious complication such as
perforation of bowel.

Adverse effects


Abdominal pain.

Pain at the injection site.


Gall stones. (With octreotide)

Drowsiness. (With diphenoxylate, and Lopramide

Drug interactions

Use diphenoxylate or loperamide with similar acting drugs causes
additive anticholinergic effects.

Antidiarrheals Notes PDF

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