What it's for (Indications)
- Octreotide acetate is indicated for the treatment of gastrinoma and other gastro-entero-pancreatic (GEP) endocrine tumors, carcinoid tumors (including metastatic carcinoid tumors to alleviate symptoms such as flushing and diarrhea), and VIP-secreting adenomas (to alleviate symptoms such as watery diarrhea).
- It is also used in patients undergoing pancreatic surgery.
- For acromegaly, it is used as a short-term treatment and as a long-term treatment in patients where dopamine agonists and radiotherapy are ineffective.
Dosage Information
| Type | Guideline |
|---|---|
| Standard | Octreotide acetate for injectable suspension should be administered intramuscularly (IM) into the gluteal region, typically at 4-week intervals, by a trained healthcare provider. Administration at intervals greater than 4 weeks is not recommended. Specific mixing instructions for the injectable suspension must be closely followed, and the prepared suspension must be administered immediately, with any unused portion discarded. The diluent should not be injected directly without preparing the suspension. The recommended needle size is 1½” 19 gauge safety injection needle; for patients with greater skin-to-muscle depth, a 2” 19 gauge needle may be used. Injection sites should be rotated to avoid irritation. |
Safety & Warnings
Common Side Effects
- Common side effects include injection site reactions, gastrointestinal problems (such as diarrhea, abdominal pain, nausea, flatulence, steatorrhea, and malabsorption of dietary fats), gallstones (cholelithiasis) and biliary colic.
- Other adverse reactions may include hyperglycemia, hypoglycemia, hair loss, hepatic dysfunction, acute pancreatitis, thyroid function abnormalities, cardiac function abnormalities (e.
- g.
- , bradycardia), changes in Vitamin B12 levels, changes in zinc levels, back pain, fatigue, headache, and dizziness.
Serious Warnings
- Black Box Warning: None
- The therapeutic effects of octreotide may diminish suddenly over time.
- Patients with diabetes may experience reduced hypoglycemic requirements.
- For carcinoid tumors, if no clinical improvement is observed within one week, discontinuation should be considered.
- There is a risk of cholelithiasis and related complications.
- Close monitoring of blood glucose is required due to potential for both hyperglycemia and hypoglycemia.
- Thyroid and cardiac function abnormalities may occur, necessitating monitoring.
- Steatorrhea and malabsorption of dietary fats may lead to nutritional deficiencies.
- Changes in Vitamin B12 and zinc levels require periodic monitoring.
- Routine laboratory tests are essential, and potential drug interactions should be considered.
- For injectable suspension, injection sites should be rotated systematically.
How it Works (Mechanism of Action)
Octreotide exerts pharmacologic actions similar to the natural hormone somatostatin. It is a more potent inhibitor of growth hormone, glucagon, and insulin than somatostatin. Like somatostatin, it suppresses LH response to GnRH, decreases splanchnic blood flow, and inhibits the release of serotonin, gastrin, vasoactive intestinal peptide, secretin, motilin, and pancreatic polypeptide.