In diarrhea-predominant IBS, which class of antidepressants is favored due to anticholinergic properties?

In diarrhea-predominant IBS, which class of antidepressants is favored due to anticholinergic properties?

• A. SSRIs
• B. Tricyclic antidepressants
• C. SNRIs
• D. MAO inhibitors

Answer: (B)

Diarrhea-predominant IBS benefits from therapies that slow bowel transit and reduce stool frequency. Anticholinergic effects achieve that by blocking muscarinic receptors in the gut, lowering motility and secretions. Tricyclic antidepressants have notable anticholinergic activity, and at low doses they can lessen diarrhea symptoms while also helping relieve visceral pain. This combination makes them preferred for IBS-D compared with SSRIs or SNRIs, which lack meaningful anticholinergic effects, and MAO inhibitors, which carry more safety concerns. Start low and monitor for constipation, dry mouth, urinary retention, and other anticholinergic side effects.

Diarrhea-predominant IBS benefits from therapies that slow bowel transit and reduce stool frequency. Anticholinergic effects achieve that by blocking muscarinic receptors in the gut, lowering motility and secretions. Tricyclic antidepressants have notable anticholinergic activity, and at low doses they can lessen diarrhea symptoms while also helping relieve visceral pain. This combination makes them preferred for IBS-D compared with SSRIs or SNRIs, which lack meaningful anticholinergic effects, and MAO inhibitors, which carry more safety concerns. Start low and monitor for constipation, dry mouth, urinary retention, and other anticholinergic side effects.