octreotide acetate: clinical use

Prescribing considerations

• Confirm the indication and choose short-acting or prolonged-release formulation for the required clinical role.
• Monitor for loss of symptom control in functional neuroendocrine tumours and pituitary-tumour expansion, including new visual symptoms.
• Assess unexplained steatorrhoea, loose stools, bloating or weight loss for pancreatic exocrine insufficiency.
• Use particular care in diabetes, insulinoma, gallbladder disease, bradycardia or conduction disease, cirrhosis and previous vitamin B12 deficiency.
• Clinical experience in children is limited.

Contraindications and cautions

• Hypersensitivity to octreotide or any formulation excipient.
• Gallstones, glucose disorders, cardiac disease and hepatic impairment are cautions requiring assessment rather than absolute contraindications.

Monitoring

• Clinical response and indication-specific biochemical markers, such as GH and IGF-1 or thyroid hormones
• Blood glucose and concurrent antidiabetic treatment
• Thyroid and liver function during prolonged treatment
• Gallbladder ultrasound before and periodically during long-term treatment
• Heart rate or ECG when clinically indicated, particularly with cardiac risk or intravenous use
• Vitamin B12 in patients with previous deficiency
• Symptoms suggesting pancreatic exocrine insufficiency or biliary complications

Clinical pharmacology

Octreotide is a synthetic somatostatin octapeptide analogue with a longer duration of action than endogenous somatostatin. It preferentially suppresses growth hormone and glucagon relative to insulin and also inhibits TSH, serotonin and several gastro-entero-pancreatic peptides.

Formulation and product differences

• Short-acting solution can be given subcutaneously or by intravenous infusion and covers perioperative pancreatic use and acute variceal bleeding.
• Prolonged-release powder requires reconstitution and deep intramuscular gluteal injection by a trained healthcare professional.
• Prolonged-release products include tumour-control licensing for selected advanced neuroendocrine tumours that is not stated for the selected short-acting product.
• Short-acting and prolonged-release formulations are not interchangeable without a planned clinical transition.

Injection

Route: Parenteral

Strengths: 50 micrograms/1 mL, 50 micrograms/mL, 100 micrograms/1 mL, 100 micrograms/mL, 200 micrograms/mL, 500 micrograms/1 mL, 500 micrograms/mL, 10 mg, 20 mg, 30 mg