Octreotide: Uses, Mechanism, Evidence, and Side Effects

Anyone researching acromegaly or carcinoid tumors will likely encounter octreotide as a mainstay treatment option. This synthetic hormone analogue has a long track record and a well-documented safety profile drawn from hundreds of clinical trials and years of real-world reporting.

Key takeaways

• Octreotide is a somatostatin analogue approved for acromegaly, carcinoid tumors, and VIPomas.
• It works by mimicking and enhancing the natural hormone somatostatin's inhibitory effects.
• It is marketed as Octreotide Acetate and carries no boxed warning.
• More than 375 registered trials have studied octreotide, often in combination with other therapies.
• The most reported adverse events involve gastrointestinal and systemic symptoms, based on FAERS reports.

What Octreotide Is

Octreotide is a synthetic peptide that acts like the natural hormone somatostatin, but with stronger and longer-lasting effects. It inhibits growth hormone, glucagon, and insulin more potently than somatostatin itself. The compound also suppresses the release of several other hormones and signaling molecules, including gastrin, secretin, motilin, and VIP, and it decreases blood flow to abdominal organs. It is identified in chemical databases under PubChem CID 448601.

What Octreotide Is Approved For

Octreotide is approved for three main uses. In acromegaly, it reduces elevated blood levels of growth hormone and insulin growth factor-1 in patients who have not responded adequately to, or cannot undergo, surgery, radiation, or maximally tolerated bromocriptine therapy. In metastatic carcinoid tumors, it is used to control the severe diarrhea and flushing episodes associated with the disease. It is also indicated for the profuse watery diarrhea caused by VIP-secreting tumors (VIPomas). The label notes that improvement in symptoms does not necessarily indicate tumor shrinkage. Octreotide is marketed as Octreotide Acetate and does not carry a boxed warning.

What the Evidence Shows

Octreotide has been studied in 377 registered clinical trials. Among the sampled studies, a completed Phase 2 trial evaluated everolimus combined with long-acting octreotide for polycystic liver disease. Another completed Phase 2 trial tested everolimus combined with octreotide LAR for advanced gastrointestinal neuroendocrine tumors. These studies reflect ongoing interest in combining octreotide with other agents for related conditions.

Reported Side Effects

Reported adverse events, drawn from FAERS data, reflect report counts rather than confirmed incidence or direct causation. The most frequently reported reactions include gastrointestinal and systemic symptoms: diarrhoea (4,580 reports), fatigue (3,543), malaise (3,031), and nausea (2,998). Death was also reported frequently (4,189 reports), alongside increased blood pressure (2,980), pain (2,604), and issues related to the injection needle (2,791). These figures represent submitted reports to a surveillance database and do not establish that octreotide caused these events.