Glucagon hydrochloride

Dose and administration

• 200 microgram/kg/dose by slow IV injection over 1 minute: or IM or SC. Maximum dose 1mg; or or IM or SC. Maximum stat dose 1mg (1000 microgram).

• Continuous infusion 20 microgram/kg/hour. Consider starting dose of 20 microgram/kg/hour and decrease carefully, monitoring blood glucose, until the minimum effective dose is reached.

Indications

To treat hypoglycaemia

• When glucose infusion is unavailable.

• Refractory hypoglycaemia with high glucose requirements and/or fluid restriction.

• In documented cases of glucagon deficiency.

Contraindications and precautions

1. Hypersensitivity to glucagon or any excipients.

2. Phaeochromocytom

3. Use with caution in infants with hypertension

Clinical pharmacology

Glucagon stimulates synthesis of cyclic AMP, especially in liver and adipose tissue. Stimulates gluconeogenesis. In high doses, glucagon has a positive 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 reported in adults is 8-18 minutes.

Evidence

The data for the use of glucagon to treat neonatal hypoglycaemia are mostly from case series and reports.¹,²,³ Glucose production in response to a glucagon 100 microgram/kg bolus was comparable in preterm, appropriately grown for age and small for gestational age infants.⁴

Possible adverse effects

Generally well tolerated. May cause transient increase in blood pressure and pulse

• Gastrointestinal disturbances (nausea and vomiting) and possible ileus

• Tachycardia.

• Rebound hypoglycaemia (result of insulin release and rebound effect).

• Hypersensitivity reactions and Anaphylaxis (rare -reported in adults).

• Hypertension and hypotension (rare).

• Hyponatraemia (variable reports)

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.

Management of Glucagon administration

Description

• White powder for reconstitution 1 mg/vial in a glass syringe prefilled with 1ml sterile water.

• Reconstituted solution is clear and colourless. Do not use if fibres or solid particles are present.

Prescription

IV, IM or subcutaneous injection glucagon is charted on the stat page of the prescription chart in microgram/dose.

Continuous infusion

Charted on fluid chart giving:

• rate in ml/hour

• dose in mg/day

Also charted on drug chart under continuous infusions giving:

• amount of drug to be added

• base fluid, type and volume

• mg/ml

Administration

Continuous infusions

1. Add 1ml of diluent water provided to the 1 mg vial (1000 microgram of glucagon).

   SINGLE STRENGTH infusion:

   - Draw up 0.5 mg/kg (0.5ml/kg) add 5% glucose to make up to a final volume of 50ml.

   - Infusing at 1ml/hour = 10 microgram/kg/hour.

    DOUBLE STRENGTH infusion:

   - Draw up 1ml/kg (1mg/kg of glucagon) add 5% glucose to make up to a final volume of 50ml. 

   - Infusing at 1ml/hour = 20 microgram/kg/hour

2. Mix well. Do not use if not clear.

3. Consider compatible in Glucose 5% and Glucose 10%. There is conflicting information on compatibility with other diluents. Consider incompatible with all other substances. Use a separate line for glucagon infusions.

4. Filter prior to administration through a Pall 0.22 micron filter.

5. Administer via a syringe pump.

6. Change fluid and tubing every 24 hours.

Slow IV injection

1. Reconstitute with water to 1mg/ml immediately prior to use.

2. Does not require further dilution. Filter prior to administration.

3. There is no data available on drug or additive compatibilities. Consider incompatible with all other substances. Precipitates in chloride and calcium solutions.

4. Administer by slow IV injection over 1 minute.

5. Flush with Glucose 5% before and after administration of glucagon.

6. Do NOT mix with any drugs, IV solutions, blood and blood products.

IM or SC Injection

Reconstitute with water to 1mg/ml immediately prior to use.

Nursing considerations

1. Assess IV site closely for signs of extravasation.

2. Observe for signs of adverse effects.

3. Observe clinical condition closely for signs of hypoglycaemia. Monitor blood glucose levels.

4. Monitor blood pressure regularly.

Storage

• At room temperature <25°C until reconstitution.

• Use immediately following reconstitution.

• Is not suitable for storage.