Octreotide acetate is a synthetic octapeptide analogue of the natural hormone somatostatin. It mimics somatostatin's pharmacological actions but has a significantly longer duration of effect. It is a potent inhibitor of growth hormone, glucagon, and insulin secretion, and reduces secretion of various gastroenteropancreatic peptides. In the Indian market, it is a critical drug for managing acromegaly, carcinoid syndrome, and acute variceal bleeding.
Adult: Acromegaly: Initial 50 mcg SC 2-3 times daily, titrate based on GH/IGF-1 levels. Usual range 100-200 mcg TID. Carcinoid/VIPoma: 100-600 mcg/day SC in 2-4 divided doses. Acute Variceal Bleeding: 50 mcg IV bolus, followed by 50 mcg/hr IV infusion for 2-5 days.
Note: For SC injection: Rotate injection sites (thigh, abdomen, buttocks). Avoid same site consecutively. For IV use: Must be diluted in Normal Saline or 5% Dextrose. Given as a slow IV bolus or continuous infusion. Do not administer if solution is discolored or contains particles.
Octreotide binds with high affinity to somatostatin receptors (primarily subtypes 2 and 5). This binding inhibits the secretion of numerous hormones and bioactive peptides. It suppresses the secretion of growth hormone (GH), insulin, glucagon, gastrin, vasoactive intestinal peptide (VIP), serotonin, and pancreatic polypeptide. It also reduces splanchnic blood flow and portal pressure.
Pregnancy: Category B: Animal studies show no risk, but no adequate human studies. Use only if clearly needed. May alter maternal glycemic control.
Driving: May cause dizziness, fatigue, or visual disturbances. Patients should be cautioned about operating machinery or driving until their response is known.
| Cyclosporine | Octreotide may reduce cyclosporine levels; monitor levels closely. | Major |
| Oral Hypoglycemics (e.g., Glibenclamide) / Insulin | Octreotide alters glycemic control; frequent glucose monitoring required. Dose of hypoglycemic may need reduction. | Major |
| Bromocriptine | Increased bioavailability of bromocriptine; monitor for increased effects. | Moderate |
| Beta-blockers (e.g., Propranolol) | Additive effect on heart rate; may cause severe bradycardia. | Moderate |
| Cisapride, Terfenadine, Erythromycin | Increased risk of QT prolongation and cardiac arrhythmias. | Major |
| Oral medications (e.g., Ciprofloxacin) | Octreotide delays gastric emptying and intestinal transit, potentially reducing absorption of co-administered drugs. Administer other drugs at least 2 hours apart. | Moderate |
Same composition (Octreotide acetate (50mcg)), different brands: