Octreotide

#completed #carded

Related FACEM curriculum (2022) learning objectives:

• ME 3.8.1.6(e) Principles of management of toxicological presentations including: Indications for antidotes
• ME 3.8.2.4 Identify the appropriate antidote or antivenom.

Toxicological Indications

• Management of hyperinsulinaemic hypoglycaemia (blood glucose <4 mmol/L), including:
  • Intentional sulfonylurea overdose.
  • Therapeutic sulfonylurea-induced hypoglycaemia.
  • Quinine-induced hypoglycaemia.

Contraindications

• None.

Mechanism of Action

• Suppresses endogenous insulin release from pancreatic islet cells.

Pharmacokinetics

• 100% bioavailability via SC administration; peak levels in 30 minutes (lower than IV levels).
• About 30% excreted unchanged by the kidney.
• Elimination half-life: 90 minutes.

Administration

• Monitor blood glucose levels and clinical features of hypoglycaemia in a monitored area.
• Initial dose: 50 micrograms IV bolus.
• Infusion:
  • 25 micrograms/hour.
  • Dilute 500 micrograms in 500 mL saline and infuse at 25 mL/hour.
• Alternative to IV infusion:
  • 100 micrograms SC/IM every 6 hours (risk of breakthrough hypoglycaemia between doses).
• Correct recurrent hypoglycaemia with 50% dextrose and double the infusion rate.
• Normoglycaemia without glucose supplementation is typically maintained on infusion.

Therapeutic Endpoints

• Maintain normoglycaemia for 12 hours off octreotide with a normal diet before medical clearance.

Adverse Drug Reactions

• Minor nausea.

Specific Considerations

• Pregnancy: Safety not established but use if clinically indicated.
• Paediatric: Dose not well-defined. Suggested dose:
  • Initial bolus: 1 microgram/kg IV or SC.
  • Infusion: 1 microgram/kg/hour IV.

Handy Tips

• For remote management, administer 100 micrograms SC as a stabilising bolus prior to transfer.
• Plasma insulin levels can guide cessation of therapy:
  • Normal plasma insulin 6 hours post-infusion indicates readiness for medical clearance.

Pitfalls

• Delayed initiation of therapy after the onset of hypoglycaemia following sulfonylurea overdose.

Controversies

• IV versus SC administration and optimal dosing strategies.
• Use in therapeutic sulfonylurea-induced hypoglycaemia management.