Octreotide: Uses, Mechanism, and Side Effects

Patients managing acromegaly or hormone-secreting tumors often ask how octreotide works and what to expect from treatment. Octreotide is a well-established synthetic hormone analogue with decades of clinical use and a substantial trial record.

Key takeaways

• Octreotide is a somatostatin analogue approved for acromegaly, metastatic carcinoid tumors, and VIPomas.
• It works by mimicking somatostatin, suppressing growth hormone, insulin, glucagon, and several gut hormones.
• More than 380 trials have studied octreotide, including completed Phase 4 and Phase 2/3 work.
• FAERS reports most commonly include diarrhoea, fatigue, malaise, nausea, and elevated blood pressure.
• The approved brand form referenced in labeling is Octreotide Acetate.

What Octreotide Is

Octreotide is a synthetic version of the natural hormone somatostatin, classified as a somatostatin analogue. It acts as a more potent inhibitor of growth hormone, glucagon, and insulin than the body's own somatostatin. The compound also reduces blood flow to abdominal organs and limits release of several signaling hormones, including serotonin, gastrin, and secretin. Through these combined actions, it helps regulate hormone levels that drive certain tumor-related symptoms and endocrine conditions.

What Octreotide Is Approved For

Octreotide Acetate Injection carries three approved indications. In acromegaly, it is used to lower growth hormone and insulin-like growth factor-1 levels in patients who have not responded adequately to, or cannot undergo, surgery, radiation, or maximal bromocriptine therapy. For metastatic carcinoid tumors, it is indicated to relieve the severe diarrhea and flushing episodes associated with the disease. It is also approved to treat the profuse watery diarrhea caused by VIP-secreting tumors (VIPomas). The label notes that improvement in symptoms does not necessarily indicate tumor regression. No boxed warning is listed for this product.

What the Evidence Shows

Octreotide has been studied in more than 380 registered clinical trials. A completed Phase 4 study examined combined use of pegvisomant and octreotide in acromegaly patients. Another completed trial, in Phase 2/3, evaluated 68Ga-DOTANOC PET/CT imaging in patients with gastroenteropancreatic neuroendocrine tumors, reflecting octreotide's role beyond direct hormone suppression.

Reported Side Effects

FAERS data reflect reported adverse events, not confirmed incidence or direct causation. The most frequently reported reactions include diarrhoea (4,598 reports), fatigue (3,564), and malaise (3,036), alongside nausea (3,008) and increased blood pressure (2,989). Death was also among the frequently reported terms (4,204), reflecting the serious underlying conditions often treated with this therapy. Additional reports describe general pain and issues related to the injection needle itself.