Flashcard · Acute Diarrhoea in Adults

What is drug-induced diarrhoea - its mechanisms, common culprits, and management?

Answer

Drug-induced diarrhoea results from direct drug effects via osmotic, secretory, motility, or mucosal-irritant mechanisms. Common culprits: metformin, magnesium-containing antacids, orlistat, antibiotics, laxatives, chemotherapy, and PPIs. Management: review and stop or substitute the drug, with rehydration; symptoms usually resolve after withdrawal.

Clinical relevance. Considering drug-induced diarrhoea identifies a reversible cause that resolves on stopping the drug.

More Detail

Drug-induced diarrhoea

Many drugs cause diarrhoea, which should be considered when there is no infective cause.

Mechanisms

Osmotic (poorly absorbed substances, e.g. magnesium salts).
Increased intestinal motility.
Secretory effects.
Mucosal irritation.

Common culprit drugs

Metabolic/GI: metformin, magnesium-containing antacids, orlistat.
Antibiotics: e.g. amoxicillin/clavulanate.
Others: laxatives, chemotherapy agents, proton pump inhibitors.

Management

Review and stop the offending drug if possible, or reduce the dose/substitute.
Oral rehydration and supportive care.
Symptoms usually resolve after withdrawal.