Endogenous peptide hormone / antidote Pregnancy: Can be used during pregnancy (does not cross the placental barrier; no known harmful effects). Can be used during breast-feeding.

Glucagon

Brand names: GlucaGen, Baqsimi (intranasal)

Glucagon is used for the emergency treatment of severe hypoglycaemia when intravenous access or oral carbohydrate is not possible. It is also used in beta-blocker overdose.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 1 mg

Route: Subcutaneous or intramuscular injection

Frequency: Single dose (emergency); if no response within 10 minutes give intravenous glucose

Severe hypoglycaemia (emergency/therapeutic indication), adult patients: administer 1 mg SC or IM. Patient normally responds within 10 minutes. Once responsive, give oral carbohydrate to restore liver glycogen and prevent relapse. If no response within 10 minutes, intravenous glucose should be given. Glucagon is ineffective when liver glycogen is depleted (prolonged fasting, adrenal insufficiency, chronic or alcohol-induced hypoglycaemia). Paediatric (severe hypoglycaemia): 0.5 mg for children below 25 kg or younger than 6–8 years; 1 mg for children above 25 kg or older than 6–8 years. Reconstitute powder with accompanying solvent immediately before use; do NOT give as an IV infusion. (US labelling for weighted paediatric dosing gives 0.5 mg or 20–30 mcg/kg for <20 kg — verify against UK SPC.) A separate diagnostic (GI motility) indication also exists: adults 0.2–0.5 mg IV or 1 mg IM to relax stomach/small bowel; 0.5–0.75 mg IV or 1–2 mg IM to relax colon.

Dose adjustments

Renal

Can be used in patients with renal and hepatic impairment (no dose adjustment stated).

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

Dosage in adult and pediatric patients to treat severe hypoglycemia ( 2.2 ) • Adults and Pediatric Patients Weighing 20 kg or More: ▪ The recommended dosage is 1 mg (1 mL) injected subcutaneously or intramuscularly into the upper arm, thigh, or buttocks, or intravenously. ▪ If there has been no response after 15 minutes, an additional 1 mg dose (1 mL) may be administered while waiting for emergency assistance. • Pediatric Patients Weighing Less Than 20 kg: ▪ The recommended dosage is 0.5 mg (0.5 mL) or dose equivalent to 20 mcg/kg to 30 mcg/kg injected subcutaneously or intramuscularly into the upper arm, thigh, or buttocks, or intravenously. ▪ If there has been no response after 15 …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2024-12-15. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Contraindications

Hypersensitivity to glucagon or to any of the excipients
Phaeochromocytoma

Side effects

Nausea
Vomiting
Abdominal pain
Hypersensitivity reactions including anaphylactic reaction/shock (very rare)
Injection site reactions

Interactions

Insulin — acts antagonistically to glucagon
Indomethacin — glucagon may lose its ability to raise blood glucose, or may produce hypoglycaemia
Warfarin — glucagon may increase the anticoagulant effect
Beta-blockers — transient increase in pulse and blood pressure

Clinical monograph

How it works

It is a hormone that mobilises hepatic glycogen, raising blood glucose; it is therefore ineffective when glycogen stores are depleted.

Prescribing in practice

It is ineffective when hepatic glycogen is depleted, such as in starvation, significant liver disease or chronic alcohol use.
Give oral carbohydrate once the person has recovered enough to swallow safely, to restore glycogen and prevent recurrence.
It can be given by carers; seek emergency help if there is no response.

Monitoring

Monitor blood glucose and conscious level after administration, and observe for recurrence of hypoglycaemia.

Counselling the patient

Carers should know how and when to use it, and how to call for emergency help.
Once you are awake and able to swallow, take a longer-acting carbohydrate snack.
Nausea and vomiting can occur after a dose.

Evidence & guidelines

Established emergency treatment for severe hypoglycaemia per the SPC and UK guidance.

Reference: JBDS Hypoglycaemia Guidelines; TOXBASE; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways

📚 MRCEM Revision

Featured in these MRCEM clinical pathways

Glucagon is a core drug in the following exam-focused workups on our sister siteReviseMRCEM.

MRCEM Primary / Intermediate / OSCE candidates: each pathway includes exam-style questions, RCEM/NICE citations, and FAQ summaries.