What are the recommended controlled medicines for treating diarrhea?

Controlled Medicines for Diarrhea

Loperamide is the primary recommended controlled medicine for diarrhea, with an initial dose of 4 mg followed by 2 mg every 2-4 hours or after each unformed stool (maximum 16 mg/day). 1

First-Line Treatment: Loperamide

Loperamide is the opioid of choice for diarrhea management because it:

• Has local activity in the gut with minimal systemic absorption
• Reduces stool weight, frequency of bowel movements, urgency, and fecal incontinence
• Has minimal central nervous system effects due to its inability to cross the blood-brain barrier 2

Dosing Protocol:

• Initial dose: 4 mg (two capsules)
• Maintenance: 2 mg (one capsule) after each unformed stool or every 2-4 hours
• Maximum daily dose: 16 mg (eight capsules) 1
• For chronic diarrhea: Once controlled, dosage should be reduced to meet individual requirements (average maintenance 4-8 mg daily) 1

Second-Line Options (When Loperamide Fails)

If diarrhea persists for more than 48 hours on high-dose loperamide, consider:

1. Octreotide:

   • Starting dose: 100-150 μg subcutaneously three times daily
   • Can be titrated up to 500 μg three times daily
   • For severe dehydration: IV administration (25-50 μg/hour) 3

2. Other Opioids:

   • Tincture of opium: 10-15 drops in water every 3-4 hours
   • Codeine: Can be used as alternative 3
   • Morphine: Used in select cases 3

3. Oral Budesonide:

   • May be effective for chemotherapy-induced diarrhea refractory to loperamide
   • Typical dose: 9 mg once daily 3

Special Considerations

For Immunotherapy-Induced Diarrhea:

• Grade 1: Loperamide with oral rehydration
• Grade 2: Add budesonide 9 mg daily (if no bloody diarrhea)
• Grade 3-4: Corticosteroids (1-2 mg/kg/day prednisone equivalent); avoid loperamide and opioids 3

For Chemotherapy-Induced Diarrhea:

• If mild to moderate diarrhea persists >24 hours: Increase loperamide to 2 mg every 2 hours and consider oral antibiotics 3
• For complicated cases: IV fluids, octreotide, and antibiotics (e.g., fluoroquinolone) 3

Precautions:

• Monitor for paralytic ileus with high-dose loperamide
• Use with caution in patients with hepatic impairment due to potentially increased systemic exposure 1
• Avoid in elderly patients taking medications that prolong QT interval 1
• Contraindicated in children under 2 years due to risk of respiratory depression 1

Adjunctive Measures

• Dietary modifications: Eliminate lactose-containing products, alcohol, and high-osmolar supplements
• Hydration: 8-10 large glasses of clear liquids daily
• Small, frequent meals (bananas, rice, applesauce, toast, plain pasta) 3

When treating infectious diarrhea, loperamide can be used safely in combination with appropriate antibiotics, which has been shown to further reduce gastrointestinal symptoms and duration of illness 4, 5.