What medications are used to treat diarrhea?

Medications for Diarrhea

Loperamide is the first-line medication for treating acute diarrhea in adults, with an initial dose of 4 mg followed by 2 mg after each loose stool (maximum 16 mg/day). 1

First-Line Medications

Antimotility Agents

• Loperamide:

  • Initial dose: 4 mg orally
  • Maintenance: 2 mg after each loose stool
  • Maximum: 16 mg per day 1
  • Continue until 12 hours after last unformed stool or until diarrhea-free for 24 hours 2
  • CAUTION: Contraindicated in children under 2 years due to risk of respiratory depression and cardiac adverse reactions 3
  • CAUTION: Avoid in bloody diarrhea, severe infection, or inflammatory bowel disease 1

• Other opioids (second-line options):

  • Tincture of opium
  • Morphine
  • Codeine 1

Anticholinergic Agents

• For grade 2 diarrhea:
  • Hyoscyamine: 0.125 mg orally/sublingually every 4 hours as needed (maximum 1.5 mg/day)
  • Atropine: 0.5-1 mg subcutaneous/IM/IV/sublingual every 4-6 hours as needed 1

Second-Line Medications

Somatostatin Analogs

• Octreotide:
  • For severe or refractory diarrhea
  • Starting dose: 100-150 μg subcutaneous/IV three times daily
  • Can be titrated up to 500 μg subcutaneous/IV three times daily
  • Alternative: 25-50 μg/hour by continuous IV infusion 1, 2

Corticosteroids

• For immunotherapy-induced diarrhea:
  • Grade 1: Symptomatic treatment only
  • Grade 2: Budesonide 9 mg once daily (if no bloody diarrhea)
  • Grade 3-4: Prednisone 1-2 mg/kg/day (IV initially) 1

Bile Acid Sequestrants

• For bile salt malabsorption:
  • Cholestyramine
  • Colestipol
  • Colesevelam 1

Special Situations

Chemotherapy-Induced Diarrhea

• 5-FU/Capecitabine toxicity:
  • Uridine triacetate: 10 g orally every 6 hours for 20 doses (within 96 hours of chemotherapy) 1

Infection-Related Diarrhea

• C. difficile infection:

  • Metronidazole: 500 mg orally/IV four times daily for 10-14 days
  • Vancomycin: 125-500 mg orally four times daily for 10-14 days 1

• Other bacterial infections:

  • Treat with appropriate antibiotics
  • For traveler's diarrhea: Quinolones (first choice) or cotrimoxazole 1

Supportive Measures

Fluid and Electrolyte Replacement

• Maintain adequate fluid intake as indicated by thirst
• Use drinks containing glucose (lemonades, sweet sodas, fruit juices) or electrolyte-rich soups 1
• For severe dehydration: IV fluids with adequate replacement of output plus insensible losses 1

Dietary Modifications

• Follow a bland/BRAT diet (Bananas, Rice, Applesauce, Toast) 1
• Avoid spicy foods, coffee, alcohol, and foods high in simple sugars and fats 1, 2
• Consider avoiding milk and dairy products (except yogurt and firm cheeses) 1

When to Seek Medical Attention

• No improvement within 48 hours
• Worsening symptoms or overall condition
• Warning signs: severe vomiting, dehydration, persistent fever, abdominal distension, or blood in stools 1

Common Pitfalls to Avoid

1. Using antimotility agents in cases of bloody diarrhea or suspected invasive infection
2. Exceeding recommended doses of loperamide (risk of cardiac adverse events) 3
3. Using loperamide in children under 2 years of age (contraindicated) 3
4. Neglecting fluid and electrolyte replacement while using antidiarrheal medications 3
5. Failing to identify and treat the underlying cause of persistent diarrhea 4

Remember that while medications can provide symptomatic relief, addressing the underlying cause and preventing dehydration are essential components of effective diarrhea management.