Diphenoxylate

What it is and how it works

Diphenoxylate is a pethidine congener that acts on intestinal opioid receptors to reduce propulsive peristalsis and increase transit time. It is usually formulated with a subtherapeutic dose of atropine (co-phenotrope) to discourage deliberate overdose.

Indications

Adjunctive symptomatic treatment of acute diarrhoea and control of faecal consistency after colostomy or ileostomy.

Dosage and administration (summary)

Adults: initially 10 mg diphenoxylate (e.g. 4 tablets of 2.5 mg), then 5 mg every 6 hours until diarrhoea is controlled; reduce the dose once control is achieved.

Contraindications

Acute ulcerative colitis, antibiotic-associated (pseudomembranous) colitis, diarrhoea due to invasive organisms, conditions where inhibition of peristalsis must be avoided (ileus, obstruction, toxic megacolon), obstructive jaundice and young children.

Warnings and precautions

Not a substitute for fluid and electrolyte replacement. Young children are particularly susceptible to overdose, which can cause delayed respiratory depression and atropinic effects. Use with caution in hepatic impairment and with CNS depressants or MAOIs; prolonged high doses may cause dependence.

Pregnancy

Avoid in pregnancy unless clearly necessary.

Storage and supply

Store below 25 °C.

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.