Medications for Diarrhea Treatment
For most adults with acute watery diarrhea, loperamide is the drug of choice, starting with an initial dose of 4 mg followed by 2 mg after each loose stool (maximum 16 mg daily). 1, 2
First-Line Medications
Antimotility Agents
- Loperamide is the preferred antimotility agent for adults with acute watery diarrhea 1, 3
- Dosing: Initial dose of 4 mg followed by 2 mg every 2-4 hours or after each loose stool, not exceeding 16 mg daily 1, 3
- Contraindications: Should not be used in children under 18 years with acute diarrhea, in cases of bloody diarrhea, high fever, or suspected inflammatory diarrhea 1
- Caution: Can cause cardiac adverse reactions including QT prolongation and Torsades de Pointes when taken at higher than recommended doses 3
Other Opioids
- Alternative opioid options include tincture of opium, morphine, or codeine when loperamide is not suitable 1
- These should be used with caution due to potential for side effects and dependence 1
Adjunctive Treatments
Fluid Replacement
- Oral rehydration solutions (ORS) are essential for treating dehydration, especially in moderate to severe cases 1
- For mild cases in adults, maintaining adequate fluid intake with glucose-containing drinks (lemonades, sweet sodas, fruit juices) or electrolyte-rich soups is recommended 1, 2
- Intravenous fluids (lactated Ringer's or normal saline) are indicated for severe dehydration, shock, altered mental status, or when oral rehydration fails 1
Probiotics
- May be offered to reduce symptom severity and duration in immunocompetent adults and children with infectious or antibiotic-associated diarrhea 1
- The specific probiotic strains, dosage, and delivery method should be based on available evidence 1
Antiemetics
- Ondansetron or other antiemetics may be given to facilitate tolerance of oral rehydration, particularly in cases with significant vomiting 1
- These should not substitute for appropriate fluid and electrolyte therapy 1
Special Situations
Chemotherapy-Induced Diarrhea
- Loperamide remains first-line (same dosing as above) 1
- Octreotide can be used for refractory cases: starting dose 100-150 μg subcutaneous/IV three times daily, can be titrated up to 500 mg three times daily 1
- For 5-FU or capecitabine-induced severe diarrhea, uridine triacetate (10 g orally every 6 hours for 20 doses) may be indicated within 96 hours of chemotherapy 1
Immunotherapy-Induced Diarrhea
- Grade 1: Oral rehydration and antidiarrheals (loperamide or racecadotril) 1
- Grade 2: Add budesonide 9 mg daily if no bloody diarrhea; use oral corticosteroids for cases with bleeding or persistent symptoms 1
- Grade 3-4: Corticosteroids (1-2 mg/kg/day prednisone equivalent); avoid loperamide; consider infliximab for persistent cases 1
Infectious Diarrhea Requiring Antibiotics
- Antibiotics are generally not recommended for most cases of acute watery diarrhea 2, 4
- Indications for antibiotics include:
- Fluoroquinolones (ciprofloxacin, levofloxacin) are first-line when indicated; azithromycin is preferred for areas with high fluoroquinolone resistance 2, 4
Dietary Considerations
- Maintain normal food intake guided by appetite; small, light meals are recommended 1
- Avoid spicy foods, coffee, alcohol, and reduce insoluble fiber intake 1
- Consider avoiding milk and dairy products (except yogurt and firm cheeses) during acute episodes 1
When to Seek Medical Attention
- No improvement within 48 hours 1, 2
- Worsening symptoms or deteriorating condition 2
- Development of warning signs: severe vomiting, dehydration, persistent fever, abdominal distension, or blood in stools 1, 2
Cautions and Contraindications
- Antimotility agents should be avoided in suspected or proven inflammatory diarrhea or diarrhea with fever 1
- Loperamide is contraindicated in children under 2 years due to risks of respiratory depression and cardiac adverse reactions 3
- Use loperamide with caution in patients taking QT-prolonging medications or with risk factors for QT prolongation 3