What is the dosing for Octreotide (somatostatin analogue) for intractable nausea and vomiting?

Octreotide Dosing for Intractable Nausea and Vomiting

For intractable nausea and vomiting, octreotide should be administered at a starting dose of 100-150 μg subcutaneously three times daily or as a continuous infusion (25-50 μg/hour), with dose escalation up to 500 μg three times daily until symptoms are controlled. 1

Indications for Octreotide in Nausea and Vomiting

Octreotide is particularly effective in specific clinical scenarios:

1. Bowel obstruction due to cancer: Octreotide is highly recommended for nausea and vomiting due to malignant bowel obstruction 1
2. Intractable symptoms unresponsive to first-line antiemetics: When dopamine receptor antagonists (e.g., haloperidol, metoclopramide) fail to control symptoms 1
3. Paraneoplastic diarrhea and associated nausea: Particularly with neuroendocrine tumors 1

Dosing Protocol

Initial Dosing

• Starting dose: 100-150 μg SC three times daily 1
• Alternative administration: Continuous SC or IV infusion at 25-50 μg/hour (if patient is severely dehydrated) 1

Dose Titration

• Titration strategy: Increase dose up to 500 μg three times daily until symptoms are controlled 1
• For long-term management: Consider depot octreotide 20-30 mg IM every 4 weeks for ongoing symptom control 1

Administration Routes

• Preferred route: Subcutaneous injection or continuous infusion
• For severe dehydration: Intravenous infusion may be preferred 1

Monitoring and Duration of Therapy

• Continue treatment until the patient has been symptom-free for at least 24 hours 1
• For malignant bowel obstruction, treatment may need to be continued indefinitely 1
• Monitor for symptom improvement within 48 hours of initiation 1

Efficacy Data

Clinical studies demonstrate high efficacy rates:

• 75-92.8% of patients with malignant bowel obstruction experience significant symptom improvement 2, 3
• Symptom control is typically achieved within 1-6 days (mean 3 days) 4
• Octreotide is significantly more effective than hyoscine butylbromide in controlling nausea and vomiting in bowel obstruction (p<0.05) 5

Combination Therapy

For optimal symptom control, consider combining octreotide with:

• Chlorpromazine (15-25 mg/day) 5
• Corticosteroids (e.g., dexamethasone) for additional anti-inflammatory effect 1
• Appropriate opioid therapy for pain management 1

Pitfalls and Caveats

1. Delayed initiation: Early administration of octreotide results in better symptom control; don't delay treatment once intractable symptoms are identified 3

2. Inadequate dosing: Failure to escalate the dose when symptoms persist may result in suboptimal control; doses up to 500 μg TID have been shown to be more effective than lower doses 1

3. Overlooking hydration status: Severe dehydration may require IV administration rather than SC 1

4. Misdiagnosis: Ensure proper diagnosis of the cause of nausea and vomiting before initiating octreotide, as it is particularly effective for specific indications like malignant bowel obstruction but may not be first-line for other causes 1

By following this evidence-based approach to octreotide dosing for intractable nausea and vomiting, clinicians can effectively manage these distressing symptoms and improve quality of life for patients with advanced illness.