What is the recommended dose of Imodium (Loperamide) for adults and children?

Recommended Dose of Imodium (Loperamide)

For adults and children 13 years and older, start with 4 mg (two capsules) initially, followed by 2 mg after each unformed stool, with a maximum daily dose of 16 mg (eight capsules). 1

Adult Dosing

Acute Diarrhea

• Initial dose: 4 mg (two capsules) 2, 1
• Maintenance: 2 mg after each unformed stool 2, 1
• Maximum: 16 mg per day (eight capsules) 2, 1
• Clinical improvement is usually observed within 48 hours 1

Chronic Diarrhea

• Initial dose: 4 mg followed by 2 mg after each unformed stool until controlled 1
• Once optimal dosage is established, may be given as single daily dose or divided doses 1
• Average maintenance dosage: 4-8 mg per day 1
• Maximum: 16 mg per day 1
• If no improvement after 10 days at 16 mg/day, further administration unlikely to help 1

Pediatric Dosing (Ages 2-12 Years)

Loperamide is contraindicated in children under 2 years of age due to risks of respiratory depression and serious cardiac adverse reactions. 1

Ages 2-5 Years (13-20 kg)

• Use liquid formulation (1 mg/5 mL) 1
• First day: 1 mg three times daily (3 mg total) 1
• Subsequent days: 1 mg/10 kg body weight only after loose stool 1

Ages 6-8 Years (20-30 kg)

• First day: 2 mg twice daily (4 mg total) 1
• Subsequent days: 1 mg/10 kg body weight only after loose stool 1

Ages 8-12 Years (>30 kg)

• First day: 2 mg three times daily (6 mg total) 1
• Subsequent days: 1 mg/10 kg body weight only after loose stool 1

Important Timing Considerations

Allow 1-2 hours between doses for loperamide to reach therapeutic effect to avoid rebound constipation. 2

Clinical Context-Specific Dosing

Travelers' Diarrhea (Mild)

• Initial: 2 tablets (4 mg), then 2 mg after each loose stool up to 16 mg/day 2
• For mild diarrhea causing little interference with activities, loperamide alone without antibiotics is appropriate 2

Cancer-Related Diarrhea (Uncomplicated)

• Initial: 4 mg, then 2 mg every 4 hours or after each unformed stool (maximum 16 mg/day) 2
• Combine with oral hydration and dietary modifications 2

Radiation-Induced Diarrhea

• Initial: 4 mg, then 2 mg every 4 hours or after each unformed stool (maximum 16 mg/day) 2
• If unresponsive to loperamide with severe toxicity, consider octreotide 100 μg three times daily 2

Critical Safety Warnings

Never exceed 16 mg per day in any patient due to risk of serious cardiac adverse reactions including QT prolongation and Torsades de Pointes. 1

Contraindications

• Children under 2 years of age 1
• Avoid in elderly patients taking QT-prolonging drugs (Class IA or III antiarrhythmics) 1

When to Stop Loperamide and Seek Further Care

• Fever, moderate to severe abdominal pain, or bloody diarrhea 2
• These symptoms indicate complicated diarrhea requiring antibiotics and possible hospitalization 2

Special Populations

Elderly

• No dose adjustment required 1
• Exercise caution with QT-prolonging medications 1

Renal Impairment

• No dose adjustment required (drug mainly excreted in feces) 1

Hepatic Impairment

• Pharmacokinetics not studied; use with caution 1

Supportive Measures

Always ensure adequate fluid and electrolyte replacement regardless of loperamide use. 1