What is the initial dose of octreotide (somatostatin analogue)?

Initial Dosage of Octreotide

The initial dose of octreotide for subcutaneous administration is 50-100 mcg two to three times daily, with specific starting doses varying by indication. 1, 2

Dosing by Indication

Acromegaly

• Initial dose: 50 mcg three times daily subcutaneously during the first 2 weeks of therapy 2
• Maintenance dose: 100-500 mcg three times daily, titrated based on GH or IGF-1 levels 2
• Most common effective dose: 100 mcg three times daily 2
• Doses greater than 300 mcg/day rarely provide additional biochemical benefit 2

Carcinoid Tumors

• Initial dose: 100-600 mcg/day in 2-4 divided doses subcutaneously during the first 2 weeks 2
• Mean initial daily dosage: 300 mcg 2
• Median maintenance dosage: approximately 450 mcg daily 2
• Clinical benefit may be seen with doses as low as 50 mcg, while some patients require up to 1500 mcg/day 1
• Experience with doses above 750 mcg/day is limited 2

VIPomas (Watery Diarrhea Hypokalaemia Achlorhydria Syndrome)

• Initial dose: 200-300 mcg/day in 2-4 divided doses subcutaneously during the first 2 weeks 2
• Dose range: 150-750 mcg 2
• Doses above 450 mcg/day are rarely required 2
• Patients with this rare life-threatening syndrome often respond dramatically to small doses 1

Administration Considerations

• Octreotide may be administered subcutaneously or intravenously 2
• For subcutaneous administration, use the smallest volume that will deliver the desired dose to reduce pain at injection site 2
• Injection sites should be rotated systematically 2
• Short-acting formulations may be used for patient stabilization (over short periods) and management of carcinoid crisis 1
• Patients may be stabilized with short-acting octreotide for 10-28 days before converting to long-acting somatostatin analogues 1

Dose Titration and Monitoring

• Dose escalation is often needed over time 1
• For acromegaly: Monitor GH or IGF-1 every two weeks after initiating therapy or with dosage change 2
• For carcinoid tumors: Measure urinary 5-hydroxyindole acetic acid, plasma serotonin, and plasma Substance P to monitor progress 2
• For VIPomas: Titrate dose against vasoactive intestinal peptide levels with normalization of levels as the target 1

Special Situations

• For carcinoid crisis prevention during procedures (anesthesia, surgery, hepatic artery embolization): Use short-acting octreotide by intravenous administration (50 mcg/h) 12 hours before, during, and 48 hours after the procedure 1
• For chemotherapy-induced diarrhea: Starting dose of 100-150 mcg subcutaneous/intravenous three times daily, which can be titrated up to 500 mcg three times daily or 25-50 mcg/h by continuous IV infusion 1

Common Pitfalls and Caveats

• Octreotide is not effective in controlling hypoglycemia in most patients with insulinoma (only effective in SSTR 2-positive cases) 1
• Somatostatin receptors are present in 70-95% of NETs but only in about half of insulinomas 1
• Side effects include fat malabsorption, gallstones, gallbladder dysfunction, vitamin A and D malabsorption, headaches, diarrhea, dizziness, and hypo/hyperglycemia 1
• For optimal imaging with somatostatin receptor scintigraphy, short-acting octreotide should be withdrawn 24-48 hours before imaging 1
• In patients with non-functioning NETs, the routine use of somatostatin analogues cannot be recommended until further evidence is available 1