When is octreotide (somatostatin analogue) given?

When to Give Octreotide

Octreotide should be given for three FDA-approved indications: symptomatic metastatic carcinoid tumors (diarrhea/flushing), VIPomas (profuse watery diarrhea), and acromegaly with inadequate response to surgery/radiation/bromocriptine. 1

Primary FDA-Approved Indications

Carcinoid Syndrome

• Initiate octreotide immediately in patients with metastatic carcinoid tumors presenting with carcinoid syndrome (severe diarrhea and flushing episodes). 2, 1
• Start with 100-600 mcg/day subcutaneously in 2-4 divided doses during the first 2 weeks, with a mean daily dosage of 300 mcg. 1
• For chronic management, transition to octreotide LAR 20-30 mg intramuscularly every 4 weeks once symptoms are controlled. 2
• Short-acting octreotide (150-250 mcg subcutaneously 3 times daily) can be added to LAR for breakthrough symptoms, as therapeutic levels of LAR are not achieved for 10-14 days after injection. 2

Tumor Control in Neuroendocrine Tumors

• In patients with clinically significant tumor burden from metastatic carcinoid tumors, initiate octreotide LAR for tumor growth control, not just symptom management. 2
• This recommendation is based on the PROMID trial showing median time to tumor progression of 14.3 months with octreotide LAR versus 6 months with placebo (P = .000072). 2
• For asymptomatic patients with low tumor burden, timing is less clear—either initiate octreotide or defer until tumor progression is documented. 2
• Patients with clinically significant progression of metastatic carcinoid tumors should be started on octreotide if not already receiving it. 2

VIPomas (Vasoactive Intestinal Peptide Tumors)

• Give octreotide for profuse watery diarrhea associated with VIP-secreting tumors. 1
• Initial dosing: 200-300 mcg/day subcutaneously in 2-4 divided doses during the first 2 weeks (range 150-750 mcg). 1
• Doses above 450 mcg/day are usually not required. 1
• Even small doses can produce dramatic cessation of diarrhea in VIPomas. 3

Acromegaly

• Initiate octreotide in acromegaly patients who have had inadequate response to or cannot be treated with surgical resection, pituitary irradiation, and bromocriptine at maximally tolerated doses. 1
• Start with 50 mcg subcutaneously three times daily, titrating based on GH and IGF-1 levels every 2 weeks. 1
• Most common effective dosage is 100 mcg three times daily, though some patients require up to 500 mcg three times daily. 1

Critical Care and Emergency Indications

Variceal Hemorrhage

• For acute variceal bleeding, give octreotide as a 50 mcg IV bolus followed by continuous infusion at 50 μg/hour. 3
• Continue for 2-5 days until hemodynamic stability is achieved. 3
• This is effective for controlling post-sclerotherapy bleeding from esophageal varices, ulcers, and esophagitis. 4

Carcinoid Crisis Prevention

• For patients with carcinoid syndrome undergoing procedures, give prophylactic octreotide by IV infusion at 50 μg/hour starting 12 hours before and continuing 24-48 hours after the procedure. 3
• Obtain cardiology consultation and echocardiogram before major surgery in patients with carcinoid syndrome, as 59% have tricuspid regurgitation. 2

Chemotherapy-Induced Diarrhea

• For severe or loperamide-refractory chemotherapy-induced diarrhea, give continuous IV infusion at 25-50 μg/hour until diarrhea resolves. 3
• Higher doses (up to 500 μg three times daily) may be more effective than lower doses. 3

Important Monitoring and Precautions

Cardiac Considerations

• Monitor for bradycardia, arrhythmias, and conduction abnormalities, particularly with IV administration. 1
• Patients with 5-HIAA levels ≥300 mcmol over 24 hours and ≥3 flushing episodes per day are at higher risk for carcinoid heart disease. 2

Metabolic Monitoring

• Monitor glucose closely as both hypoglycemia and hyperglycemia may occur; adjust anti-diabetic medications accordingly. 1
• Assess thyroid function (total and/or free T4) at baseline and periodically, as hypothyroidism may develop. 1
• Monitor for cholelithiasis periodically and discontinue if complications are suspected. 1

Biochemical Markers

• For carcinoid tumors: measure urinary 5-HIAA, plasma serotonin, and plasma Substance P to monitor therapy progress. 1
• For VIPomas: measure plasma VIP levels to assess response. 1
• For acromegaly: monitor GH and IGF-1 levels every 2 weeks after initiation or dose changes. 1

Common Pitfalls to Avoid

• Do not discontinue octreotide prematurely in variceal bleeding before achieving hemodynamic stability. 3
• Do not use inadequate dosing for severe secretory diarrhea in carcinoid syndrome or VIPomas—titrate aggressively based on clinical response. 3
• Remember that octreotide LAR requires 10-14 days to reach therapeutic levels—bridge with short-acting formulation for immediate symptom control. 2
• Discontinue octreotide at least 24 hours prior to each lutetium Lu 177 dotatate dose to avoid interference with somatostatin receptor targeting. 1