Gastrointestinal/Antidiarrhoeals & antispasmodics

Antidiarrhoeals & antispasmodics

also: loperamide · hyoscine · mebeverine · IBS · antispasmodic

Overview

Symptomatic drugs for diarrhoea and bowel cramp/IBS — with the important caution about not slowing the gut in inflammatory/infective colitis.

Mechanism

Loperamide is a peripheral µ-opioid agonist on gut myenteric plexus → slows transit (no CNS effect). Antispasmodics — antimuscarinics (hyoscine) or direct smooth-muscle relaxants (mebeverine) — relieve colicky pain.

Indications

Symptomatic diarrhoea (loperamide)
IBS cramp / spasm (antispasmodics)

The agents

Loperamideantimotility

Symptomatic diarrhoea/IBS-D.

Hyoscine butylbromide (Buscopan)antimuscarinic

Colic/spasm; antimuscarinic cautions.

Mebeverinedirect relaxant

IBS cramp.

Adverse effects

Constipation, bloatingcommon

Hyoscine: antimuscarinic effectscommon

Cautions & contraindications

Loperamide/antimotility in active UC / C. difficile / bloody diarrhoeaall

Risk of toxic megacolon — do not slow the gut in inflammatory/infective colitis.

Antimuscarinics in angle-closure glaucoma / obstructionall

Interactions

Additive antimuscarinic burden

Monitoring & kinetics

Symptom response; exclude infective/inflammatory cause first

Oral. Symptomatic only — find the cause.

Source: NICE CKS — Diarrhoea / IBS · BNF — Antimotility / antispasmodics