What is the treatment for Monoamine Oxidase Inhibitor (MAOI)-induced diarrhea?

Treatment of MAOI-Induced Diarrhea

The first-line treatment for MAOI-induced diarrhea is loperamide at an initial dose of 4 mg followed by 2 mg every 2-4 hours or after every unformed stool, not exceeding 16 mg daily. 1

Initial Management Approach

• Implement dietary modifications by eliminating lactose-containing products, alcohol, and high-osmolar supplements 1
• Encourage consumption of 8-10 large glasses of clear liquids daily (e.g., electrolyte solutions, broth) 1
• Recommend frequent small meals consisting of low-residue foods (e.g., bananas, rice, applesauce, toast, plain pasta) 1
• Monitor and record the number of stools and report any symptoms of life-threatening sequelae (e.g., fever, dizziness upon standing) 1

Pharmacological Management

First-Line Treatment

• Start loperamide at an initial dose of 4 mg followed by 2 mg every 2-4 hours or after every unformed stool (maximum 16 mg/day) 1
• Continue loperamide until 12 hours after diarrhea resolves 1

For Persistent Diarrhea (>24 hours on standard loperamide)

• Increase loperamide dose to 2 mg every 2 hours 1
• Consider adding oral antibiotics as prophylaxis for infection if risk factors present 1

For Refractory Diarrhea (>48 hours on high-dose loperamide)

• Discontinue loperamide and switch to second-line agents 1:
  • Octreotide (100-150 μg SC TID, can be titrated up to 500 μg TID) 1
  • Diphenoxylate with atropine as an adjunctive therapy 2
  • Oral budesonide for loperamide-refractory diarrhea 1
  • Other opioids such as tincture of opium, morphine, or codeine 1

For Severe Diarrhea (with dehydration)

• Administer intravenous fluids to correct dehydration 1
• Consider octreotide IV (25-50 μg/hr) if severe dehydration is present 1
• Perform stool workup, CBC, and electrolyte profile 1

Special Considerations

• For bile salt malabsorption, which may contribute to MAOI-induced diarrhea, bile acid sequestrants (e.g., cholestyramine, colestipol, colesevelam) may be effective adjuvant therapies 1
• Avoid spices, coffee, and foods with insoluble fiber 1
• Patients on MAOIs should already be avoiding tyramine-rich foods that could potentially worsen gastrointestinal symptoms 3, 4

Important Precautions

• Use diphenoxylate with caution as it may interact with MAOIs 2
• Monitor for potential drug interactions, as MAOIs can interact with many medications including serotonergic agents 4, 5
• Evaluate for other causes of diarrhea, especially if symptoms are severe or persistent despite appropriate management 1
• Be vigilant for signs of dehydration or electrolyte imbalances, which require prompt intervention 1

When treating MAOI-induced diarrhea, a stepwise approach starting with dietary modifications and loperamide is recommended, with escalation to second-line agents if symptoms persist. Close monitoring for complications and potential drug interactions is essential throughout treatment.