Bone & endocrine
Octreotide
The first synthetic somatostatin analogue, approved for acromegaly, neuroendocrine tumours and variceal bleeding.
What it is
Octreotide is a synthetic eight-amino-acid analogue of somatostatin. It activates somatostatin receptors, mainly subtypes 2 and 5, which broadly inhibit hormone secretion and gut motility, and it resists enzymatic breakdown far better than the natural hormone. It comes as a short-acting subcutaneous injection and as a monthly long-acting depot (octreotide LAR).
How it works
- 1
Activates somatostatin receptors SSTR2 and SSTR5 on pituitary and neuroendocrine tumour cells, suppressing hormone release.
- 2
Inhibits secretion of growth hormone, gastrin, VIP, glucagon, insulin and serotonin.
- 3
Reduces splanchnic blood flow, lowering portal pressure.
- 4
Slows gut transit and reduces exocrine pancreatic and intestinal secretion.
- 5
The depot formulation releases slowly from polymer microspheres over about four weeks.
What it's studied for
Reported and studied effects
- Falls in growth hormone and IGF-1 in acromegaly, with biochemical control in roughly half of patients
- Rapid relief of flushing and diarrhoea in carcinoid syndrome
- Lower portal pressure during bleeding
- Gallstones and biliary sludge over months of use
- Slower progression of tumour markers, though not reliably tumour shrinkage
Research protocol notes
Research context onlyResearch context only - prescription medicine. Short-acting octreotide is typically 50 to 200 micrograms subcutaneously two to three times daily, with higher doses used in carcinoid crisis, while the long-acting depot is commonly 20 to 30 mg intramuscularly every four weeks after a short-acting run-in. Acromegaly endpoints are measured over months, and gallbladder ultrasound is routine during long-term use.
These figures are described so you can understand what researchers did. They are not a dose, a schedule, or a suggestion — and they are not a substitute for a doctor.
Possible side effects and contraindications
Safety profile
Possible side effects
- Gallstones and biliary sludge
- Diarrhoea and steatorrhoea
- Abdominal pain and nausea
- Glucose swings, both hyperglycaemia and hypoglycaemia
- Bradycardia
- Injection-site pain
- Hypothyroidism with long-term use
Contraindications and cautions
- Prior hypersensitivity to octreotide
- Uncontrolled diabetes needs close monitoring rather than avoidance
- Cardiac conduction abnormalities need caution
- Pregnancy only if clearly needed
A side-effect list is never complete, and these are not the only situations that warrant caution. Anything unexpected, or anything you are unsure about, should be discussed with a doctor before use.
Evidence assessment
Long clinical use and consistent biochemical or symptom endpoints, but most acromegaly and neuroendocrine trials are small and open-label rather than large placebo-controlled studies.
References
- 01European Medicines Agency - Sandostatin product information
- 02Melmed et al., Guidelines for acromegaly management, Journal of Clinical Endocrinology and Metabolism 2009
References link to published literature, regulator pages or literature indexes. Where a link points to a search, it collects the peer-reviewed work on that molecule rather than a single study.
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