1. Introduction
Loperamide is an anti-diarrhoeal medication that works by slowing intestinal motility through its action on the mu-opioid receptors in the gut. It reduces stool frequency and volume while improving stool consistency without affecting central nervous system activity.
2. Indications
- Approved Indications:
- Acute diarrhoea.
- Chronic diarrhoea associated with irritable bowel syndrome (IBS).
- Diarrhoea due to inflammatory bowel disease (adjunctive therapy).
- Reduction of stool output in patients with ileostomy.
- Off-Label Uses:
- Traveller’s diarrhoea (mild cases).
3. Dosage
- Adults:
- Acute Diarrhoea:
- Initial dose: 4 mg (2 tablets), followed by 2 mg after each loose stool.
- Maximum dose: 16 mg/day (8 tablets).
- Chronic Diarrhoea:
- Initial dose: 4 mg/day, adjusted based on response.
- Usual maintenance dose: 2–12 mg/day.
- Acute Diarrhoea:
- Children (≥6 years):
- Acute Diarrhoea:
- 2 mg after the first loose stool, then 1 mg per subsequent loose stool.
- Maximum daily dose varies by weight and age (consult packaging or specialist).
- Acute Diarrhoea:
- Elderly:
- No dose adjustment is necessary, but monitor for side effects.
4. Administration
- Take orally with water.
- Tablets should be swallowed whole.
- For oral solution or chewable tablets, follow the manufacturer’s instructions.
5. Forms Available
- Tablets: 2 mg.
- Capsules: 2 mg.
- Oral solution: 1 mg/5 mL.
6. Side Effects
6.1. Common Side Effects
- Constipation.
- Abdominal cramps.
- Dizziness.
6.2. Less Common Side Effects
- Nausea.
- Dry mouth.
- Flatulence.
6.3. Rare but Serious Side Effects
- Toxic megacolon (especially in patients with inflammatory bowel disease).
- Severe constipation or ileus.
- Allergic reactions (e.g., rash, swelling, difficulty breathing).
- Cardiac arrhythmias (at excessive doses).
7. Warnings
- Severe Diarrhoea: Avoid use if diarrhoea is associated with blood in stools or high fever, as it may mask underlying infections.
- Cardiac Risks: High doses may cause QT prolongation, torsades de pointes, or sudden cardiac death.
- Toxic Megacolon: Use cautiously in patients with inflammatory bowel disease due to the risk of bowel obstruction.
8. Precautions
- Avoid prolonged use in acute diarrhoea (no longer than 48 hours without consulting a doctor).
- Do not use in children <6 years without medical advice.
- Ensure adequate hydration and electrolyte replacement during diarrhoea treatment.
9. Interactions
- Drug-Drug Interactions:
- Ritonavir, quinidine: May increase loperamide levels, increasing the risk of side effects.
- CNS depressants (e.g., alcohol): May enhance drowsiness or dizziness.
- P-glycoprotein inhibitors (e.g., verapamil): Increased loperamide concentrations.
- Drug-Food Interactions:
- None significant; can be taken with or without food.
10. Monitoring Parameters
- Frequency and consistency of stools.
- Signs of dehydration (e.g., dry mouth, reduced urination).
- Cardiac monitoring if high doses are used (e.g., ECG for QT prolongation).
11. Use in Children
- Approved for children ≥6 years for acute diarrhoea but use cautiously.
- Avoid in children <6 years due to increased risk of side effects and toxicity.
12. Use in Pregnancy
- Category C: Use only if the potential benefits outweigh the risks. No evidence of harm in human studies, but data are limited.
13. Use in Elderly
- Safe at standard doses, but monitor for constipation or dehydration.
14. Use in Kidney Disease
- No dose adjustments are necessary, as loperamide is not significantly excreted by the kidneys.
15. Use in Liver Disease
- Use cautiously in severe liver impairment, as loperamide is metabolised in the liver, increasing the risk of central nervous system side effects.
16. Patient Counselling Points
- Take loperamide as directed and avoid exceeding the recommended dose.
- Stay hydrated and consider oral rehydration solutions to replace lost fluids and electrolytes.
- Do not use loperamide for diarrhoea with blood in stools or fever; consult a doctor instead.
- Stop using and consult a doctor if diarrhoea persists for more than 48 hours or if constipation develops.
- Report any symptoms of severe abdominal pain, swelling, or irregular heartbeat immediately.
17. Table of Brand Names, Manufacturers, and Prices
Brand Name | Manufacturer | Price (USD) |
---|---|---|
Imodium | Johnson & Johnson | $5–10 (12 tablets, 2 mg) |
Generic Loperamide | Various manufacturers | $2–5 (12 tablets, 2 mg) |
18. FAQs (15 Questions)
- What is loperamide used for?
It is used to treat acute and chronic diarrhoea and reduce stool output in ileostomy patients. - How does loperamide work?
It slows bowel movements by acting on mu-opioid receptors in the gut, improving stool consistency and reducing frequency. - How quickly does loperamide work?
It usually starts working within 1–2 hours after taking the first dose. - Can loperamide stop diarrhoea completely?
It reduces diarrhoea but does not treat the underlying cause. - What are common side effects of loperamide?
Common side effects include constipation, abdominal cramps, and dizziness. - Can loperamide be used for children?
Yes, for children ≥6 years, but avoid use in younger children without medical advice. - Is loperamide safe during pregnancy?
It can be used if necessary, but consult your doctor first. - Can I take loperamide for traveller’s diarrhoea?
Yes, it is effective for mild traveller’s diarrhoea but avoid in cases of infection with blood in stools or fever. - Can I drink alcohol while taking loperamide?
Avoid alcohol, as it may increase dizziness or drowsiness. - What should I do if I miss a dose of loperamide?
Take it as soon as possible, but do not double the dose. - How long can I take loperamide?
Use for no longer than 48 hours without consulting a doctor. - Can loperamide cause constipation?
Yes, constipation is a common side effect, especially with prolonged use. - Does loperamide treat the cause of diarrhoea?
No, it only controls symptoms. Treating the underlying cause may require other medications. - Can loperamide be taken with antibiotics?
Yes, it is often used alongside antibiotics for bacterial diarrhoea, but consult your doctor first. - How should loperamide be stored?
Store at room temperature, away from light and moisture.