Digestive health · Anti-diarrhoeal (opioid receptor agonist, peripheral)

Loperamide

Loperamide is used for short-term relief of uncomplicated acute diarrhoea in adults and older children.

OTCPregnancy: cautionLiver warningAlcohol interactionNot for young childrenSenior precaution
ImodiumDiarrestinLopamide
Overview & typical uses

Loperamide is used for short-term relief of uncomplicated acute diarrhoea in adults and older children.

Primary uses

  • Short-term relief of acute diarrhoea
  • Symptom control in some chronic conditions under clinical supervision
How it works

Slows intestinal movement, giving stools more time to reabsorb water and become firmer. Acts on peripheral opioid receptors in the gut — does not typically enter the brain at usual doses.

Available forms & strengths
  • Capsule — 2 mg (Oral)
  • Orally disintegrating tablet — 2 mg (Oral)
  • Oral solution — 1 mg / 5 mL (Oral)
General precautions & contraindications

Do not use if

  • Bloody diarrhoea or high fever (suggests infection needing evaluation)
  • Severe ulcerative colitis flare
  • Antibiotic-associated colitis
  • Children under 12 without medical supervision

Pregnancy

Use with caution — discuss with clinician. Occasional short-term use is usually acceptable; discuss with a clinician for regular use.

Breastfeeding

Generally considered safe. Very little passes into breast milk at usual amounts.

Liver considerations

  • Use with caution and lower amounts in severe liver disease.

Paediatric use

Not recommended under 12 years.

Older adults

Ensure hydration; avoid if bloody stools or high fever.

Common side effects
  • Constipation
  • Abdominal cramps
  • Dry mouth
  • Nausea
Serious warnings — seek help if these appear
  • Ileus (bowel paralysis) — stop and seek help for severe bloating with no bowel motion
  • Serious cardiac rhythm problems at high overdoses
  • Serious allergic reaction
Drug interactions
Quinidine, ritonavir, other P-glycoprotein inhibitorswarning

Can raise loperamide blood levels and heart rhythm risk.

Other CNS depressantscaution

Additive drowsiness in sensitive individuals.

Food & alcohol precautions
Water and oral rehydration salts

Should be used alongside loperamide to prevent dehydration.

Alcohol

  • Alcohol may worsen dehydration during diarrhoea.
Storage, missed dose & overdose

Storage

Store below 25 °C, out of reach of children.

If a dose is missed

Used as needed after loose stools; do not exceed the maximum daily amount on the label.

Overdose

Overdose can cause severe cardiac rhythm problems and drowsiness. Seek urgent medical help.

What to monitor

  • Stop and seek clinical advice if diarrhoea persists more than 48 hours, or you have blood in stool, high fever, or severe abdominal pain.
Frequently asked questions
Should I take loperamide for stomach-flu diarrhoea?

For uncomplicated adult cases it can help, but avoid if you have blood in stool, high fever, or severe pain.

Medical references
  • British National Formulary — LoperamideBNF (NICE)
  • FDA drug safety — LoperamideU.S. Food & Drug Administration

Content last reviewed: 2025-01-01

Medical disclaimer

This information is for educational purposes only and should not replace professional medical advice. Please consult a licensed pharmacist or clinician for advice tailored to your personal circumstances.