Glucagon

How it works

Glucagon stimulates hepatic glycogenolysis and gluconeogenesis to raise blood glucose, an effect that depends on adequate hepatic glycogen stores.

Prescribing in practice

• The most important safety point is that glucagon is ineffective when hepatic glycogen is depleted (for example in starvation, prolonged hypoglycaemia, chronic alcohol use, or adrenal insufficiency), so oral or intravenous glucose must follow once the patient can swallow or access allows.
• After recovery, give oral carbohydrate to replenish glycogen and prevent recurrent hypoglycaemia.
• Use with caution in phaeochromocytoma, insulinoma, and glucagonoma.

Monitoring

Monitor blood glucose and conscious level after administration, ensuring the patient eats carbohydrate once able and is observed for recurrence.

Counselling the patient

• Family or carers should be trained to recognise severe hypoglycaemia and to give the injection.
• After it works, eat a carbohydrate snack as soon as you can swallow safely.
• Always seek follow-up, as nausea and vomiting are common afterwards and low glucose can recur.

Evidence & guidelines

Glucagon is recommended for out-of-hospital treatment of severe hypoglycaemia in people with diabetes by NICE and national diabetes guidance.