octreotide
Brand: Sandostatin, Sandostatin LAR
Prototype Drug
Drug Class: somatostatin analog
Drug Family: antilipemic
Subclass: synthetic somatostatin octapeptide
Organ Systems: endocrinegastrointestinal
Mechanism of Action
Synthetic analog of somatostatin with a longer half-life. Binds somatostatin receptors (predominantly SSTR2 and SSTR5) on pituitary, pancreatic, and GI cells, inhibiting GH, IGF-1, insulin, glucagon, VIP, and gastrin secretion. Also reduces splanchnic blood flow by vasoconstriction of portal vasculature.
somatostatin receptors (SSTR2, SSTR5) on GH-secreting and other cells
Indications
- acromegaly (excess GH/IGF-1)
- carcinoid syndrome (VIPoma, glucagonoma, gastrinoma)
- variceal bleeding (portal hypertension)
- diarrhea/flushing from neuroendocrine tumors
- refractory hypoglycemia (insulinoma)
- Cushing's disease (off-label)
Contraindications
- hypersensitivity to octreotide or excipients
Adverse Effects
Common
- nausea
- diarrhea
- abdominal pain
- flatulence
- cholelithiasis (bile stasis)
- hyperglycemia or hypoglycemia
Serious
- gallstones (up to 50% with long-term use)
- bradycardia and conduction abnormalities
- hypothyroidism (long-term)
Pharmacokinetics (ADME)
| Absorption | subcutaneous, IV, or IM depot (LAR form monthly) |
| Distribution | 65% protein bound |
| Metabolism | hepatic; proteolytic degradation |
| Excretion | renal (32%) and biliary |
| Half-life | 1.7–1.9 hours (SC); LAR: 23–30 days (effective) |
| Onset | minutes (SC/IV) |
| Peak | 0.4 hours (SC) |
| Duration | 4–12 hours (SC); 4 weeks (LAR) |
| Protein Binding | 65% |
| Vd | 0.27 L/kg |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| cyclosporine | octreotide reduces cyclosporine absorption | major |
| beta-blockers | octreotide may enhance bradycardia | moderate |
| insulin/antidiabetics | octreotide alters glucose homeostasis; glucose must be monitored | moderate |
Nursing Considerations
- For variceal bleeding: administer IV infusion 25–50 mcg/hour for 3–5 days; monitor blood pressure and heart rate for bradycardia.
- Initiate dose rotation for SC injection; allow solution to warm to room temperature for 20 minutes to reduce discomfort.
- Monitor blood glucose closely; octreotide inhibits both insulin and glucagon, with unpredictable net effect on glucose.
- Baseline and periodic gallbladder ultrasound recommended for long-term therapy due to cholelithiasis risk.
Clinical Pearls
- Octreotide is the pharmacological treatment of choice for acute variceal bleeding (in combination with endoscopy), acting via splanchnic vasoconstriction that reduces portal blood flow.
- The LAR (long-acting repeatable) depot form delivered IM monthly dramatically improves compliance for long-term management of acromegaly and carcinoid syndrome.
Safety Profile
Pregnancy use-with-caution
Lactation avoid
Renal Adjustment Required
Hepatic Adjustment Required
TDM Not required
Concordance Terms
Cross-referenced clinical concepts — click any term to see all content where it appears.