Dose and Administration

1. 100 to 300 mcg/kg/dose by slow IV injection over 1 minute: or IM or SC. Maximum dose 1mg.
2. Continuous infusion 1-1.5mg/day. Usual dilution add 1mg glucagon to 23ml D5W or D10W, 1ml/hour = 1mg/day.

Indications

1. To treat hypoglycaemia
   1. When dextrose infusion is unavailable.
   2. In documented cases of glucagon deficiency.
   3. Refractory hypoglycaemia with high dextrose requirements and/or fluid restriction.

Contraindications and Precautions

1. Hypersensitivity to protein compounds.

Clinical Pharmacology

Glucagon stimulates synthesis of cyclic AMP, especially in liver and adipose tissue. Stimulates gluconeogenesis. In high doses, glucagon has a cardiac inotropic effect. Inhibits small-bowel motility and gastric acid secretion.

Glucagon is secreted by the alpha-cells of the pancreas and transported via the portal circulation to the liver where the major portion is bound. From the liver it is excreted into the bile. A lesser portion is distributed to other organs, particularly the kidneys which have a high binding capacity for it. It is degraded enzymatically in blood plasma and in the organs to which it is distributed. Metabolised primarily in the liver.

Increased blood glucose levels occur within 5-30 minutes after injection and fall to normal or hypoglycaemia levels within 1-2 hours. Half-life is about 5 minutes.

Possible Adverse Effects

1. Gastrointestinal disturbances (nausea and vomiting).
2. Tachycardia.
3. Rebound hypoglycaemia (result of insulin release and rebound effect).
4. Hypersensitivity reactions.
5. Anaphylaxis (rare).
6. Hypotension (rare).
7. ? ileus.

Special Considerations

1. Supplemental carbohydrates should be ongoing, parenteral or PO.
2. Follow blood glucoses closely.
3. May be of less benefit if liver glycogen stores are low or insulin secretion is excessive e.g. SGA babies or insulinoma.