What is the maximum recommended dose of Imodium (loperamide) in 24 hours?

Maximum Recommended Dose of Imodium (Loperamide) in 24 Hours

The maximum recommended daily dose of Imodium (loperamide) for adults is 16 mg (eight 2 mg capsules) in a 24-hour period. 1

Dosing Guidelines for Adults

• For acute diarrhea in adults, the recommended initial dose is 4 mg (two capsules) followed by 2 mg (one capsule) after each unformed stool, not to exceed 16 mg (eight capsules) in a 24-hour period 1
• For chronic diarrhea in adults, the same maximum daily dosage applies (16 mg per day), although the average maintenance dosage in clinical trials was 4 to 8 mg (two to four capsules per day) 1
• If clinical improvement is not observed after treatment with 16 mg per day for at least 10 days, symptoms are unlikely to be controlled by further administration 1

Special Population Considerations

• Elderly patients: No dose adjustment is required specifically for age, but caution is advised in elderly patients taking medications that can prolong the QT interval 1
• Renal impairment: No dosage adjustment is required for patients with renal impairment as the drug and its metabolites are mainly excreted in feces 1
• Hepatic impairment: Use with caution in patients with hepatic impairment as systemic exposure may be increased due to reduced metabolism 1

Safety Considerations

• Exceeding the recommended maximum dose can lead to serious cardiac adverse reactions 1, 2
• At therapeutic doses (≤16 mg/day), loperamide has a large safety margin 2
• However, at extreme exposure levels observed in abuse cases or overdose, loperamide can cause cardiac arrhythmias through inhibition of sodium channels and hERG-mediated potassium currents 2
• The FDA has issued warnings about serious cardiac events including QT prolongation, torsades de pointes, cardiac arrest, and death with very high doses of loperamide 3

Cancer-Related Diarrhea

• For chemotherapy-induced diarrhea, the same maximum daily dose of 16 mg applies 4
• In patients with cancer-related diarrhea, loperamide is generally the opioid of choice because it has local activity in the gut with minimal systemic absorption 4
• Patients using high-dose loperamide for chemotherapy-induced diarrhea should be monitored for the rare risk of paralytic ileus 4

Monitoring and Precautions

• Patients should receive appropriate fluid and electrolyte replacement as needed 1
• Clinical improvement is usually observed within 48 hours of starting treatment 1
• Pay attention to the risk of causing paralytic ileus, especially when using higher doses 4
• Avoid loperamide in patients taking drugs that can result in prolongation of the QT interval (e.g., Class IA or III antiarrhythmics) 1

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