Recommended Dosage of Imodium (Loperamide)
The recommended initial dose of Imodium (loperamide) is 4 mg (two capsules) followed by 2 mg (one capsule) after each unformed stool, with a maximum daily dose of 16 mg (eight capsules). 1
Adult Dosing Guidelines
Acute Diarrhea (Adults and Children 13+ Years)
- Initial dose: 4 mg (two capsules)
- Maintenance: 2 mg (one capsule) after each loose stool
- Maximum daily dose: 16 mg (eight capsules)
- Clinical improvement typically occurs within 48 hours 1
Chronic Diarrhea (Adults)
- Initial dose: 4 mg (two capsules)
- Maintenance: 2 mg (one capsule) after each loose stool until diarrhea is controlled
- Average daily maintenance dose: 4-8 mg (two to four capsules)
- Maximum daily dose: 16 mg (eight capsules)
- If no improvement after 10 days at maximum dose, symptoms are unlikely to respond to continued treatment 1
Special Populations
Pediatric Dosing (2-12 Years)
- Ages 2-5 years (13-20 kg): 1 mg three times daily (3 mg total daily)
- Ages 6-8 years (20-30 kg): 2 mg twice daily (4 mg total daily)
- Ages 8-12 years (>30 kg): 2 mg three times daily (6 mg total daily)
- Contraindicated in children under 2 years due to risk of respiratory depression and cardiac adverse events 1
Elderly Patients
- No dose adjustment required specifically for age
- Use with caution in elderly patients taking medications that can prolong QT interval
- Elderly may be more susceptible to QT interval effects 1
Renal Impairment
- No dosage adjustment required (drug and metabolites mainly excreted in feces) 1
Hepatic Impairment
- Use with caution due to potentially increased systemic exposure from reduced metabolism 1
Important Administration Notes
- Therapeutic effect begins within 1-2 hours after dosing 2
- Always provide appropriate fluid and electrolyte replacement alongside loperamide 1
- For uncomplicated diarrhea, combine with:
- Oral hydration
- Dietary modifications (eliminating lactose-containing products and high-osmolar supplements) 3
Warning Signs Requiring Medical Evaluation
- Fever persisting >24 hours
- Bloody stools
- Severe abdominal pain
- Dizziness upon standing
- Symptoms worsening despite treatment 2
Efficacy Considerations
Loperamide has been shown to be effective in controlling diarrhea symptoms, with studies demonstrating:
- Faster control of symptoms compared to bismuth subsalicylate 4
- Effective symptomatic relief in acute non-specific diarrhea 5
- When combined with antibiotics like rifaximin, provides more rapid symptomatic improvement than either agent alone 6
Remember that loperamide treats symptoms but does not address underlying causes of diarrhea. If symptoms persist beyond 48 hours or are accompanied by fever, severe abdominal pain, or bloody stools, further medical evaluation is warranted.