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Endogenous peptide hormone / antidote Pregnancy: UK SPC §4.6, verbatim: 'Glucagon does not cross the human placenta barrier. The use of glucagon has been reported in pregnant women with diabetes and no harmful effects are known with respect to the course of pregnancy and the health of the unborn and the neonate. GlucaGen can be used during pregnancy.' Breast-feeding: 'the amount excreted in the milk of nursing mothers following treatment of severe hypoglycaemic reactions is expected to be extremely small. As glucagon is degraded in the digestive tract and cannot be absorbed in its intact form, it will not exert any metabolic effect in the child. GlucaGen can be used during breast-feeding.' Fertility: 'Studies in rats have shown that glucagon does not cause impaired fertility.' US label §8.1 agrees: available data 'have not identified a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes.'

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.

Adult dose

Dose: Severe hypoglycaemia: 1 mg
Route: Subcutaneous or intramuscular injection. UK SPC §4.2: 'Administer 1 mg by subcutaneous or intramuscular injection.' The US label additionally permits the intravenous route: 'Administer intravenously ONLY under medical supervision.'
Frequency: Single dose. UK SPC: 'The patient will normally respond within 10 minutes... If the patient does not respond within 10 minutes, intravenous glucose should be given.' US label: 'If there has been no response after 15 minutes, an additional 1 mg dose (1 mL) of Glucagon for Injection may be administered while waiting for emergency assistance.'
SCOPE - this is the severe hypoglycaemia dose, the primary indication of this emergency-medicine page. Verbatim UK SPC §4.2: 'Therapeutic indication (Severe hypoglycaemia) Dosage for adult patients: Administer 1 mg by subcutaneous or intramuscular injection.' Preparation and after-care, UK SPC: 'Dissolve the compacted powder in the accompanying solvent'; 'Due to the instability of GlucaGen in solution, the product should be given immediately after reconstitution and must not be given as an intravenous infusion'; 'When the patient has responded to the treatment, give oral carbohydrate to restore the liver glycogen and prevent relapse of hypoglycaemia.' NO MAXIMUM DOSE IS STATED for this indication in either label - only a repeat dose - so maxDose is deliberately empty. The high-dose beta-blocker / calcium-channel-blocker overdose regimen appears NOWHERE in either fetched label, and intranasal glucagon (Baqsimi) is not in this bundle at all. The bundle's other licensed indication is diagnostic, not therapeutic, and is a different use: UK SPC 'Diagnostic indication (Inhibition of gastrointestinal motility) ... the diagnostic dose for relaxation of the stomach, duodenal bulb, duodenum and small bowel is 0.2-0.5 mg given as intravenous injection or 1 mg given intramuscularly; the dose to relax the colon is 0.5-0.75 mg intravenously or 1-2 mg intramuscularly.' Effectiveness caveat (UK SPC §4.4): 'Glucagon will not be effective in patients whose liver glycogen is depleted.'

Paediatric dose

Route: Subcutaneous or intramuscular injection (UK SPC); the US label also permits a healthcare provider to give the same dose intravenously
Frequency: Single dose. US label: 'If there has been no response after 15 minutes, an additional 0.5 mg dose (0.5 mL) of Glucagon for Injection may be administered while waiting for emergency assistance' (patients under 20 kg; an additional 1 mg dose for those 20 kg or more)
Concentration: 1 mg/ml
WEIGHT-BANDED, NOT PER-KG - dosePerKg is deliberately null, so no weight calculation is offered. UK SPC §4.2, severe hypoglycaemia, paediatric population (under 18 years - the '<' is lost in the fetched text), verbatim: 'Administer 0.5 mg (children below 25 kg or younger than 6-8 years) or 1 mg (children above 25 kg or older than 6-8 years).' The US label §2.2 uses a different threshold: 'Adults and Pediatric Patients Weighing 20 kg or More: The recommended dosage is 1 mg (1 mL) injected subcutaneously or intramuscularly...'; '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'. That per-kg figure applies only below 20 kg, not across the paediatric range, which is why it is not used as dosePerKg. concentration = 1 is the reconstituted strength, verbatim: 'The reconstituted solution is 1 mg per mL glucagon.' No maximum dose is stated for this indication in either label. Diagnostic (gastrointestinal motility) use in children is NOT established - UK SPC: 'The safety and efficacy of GlucaGen for inhibition of gastrointestinal motility in children and adolescents have not been established. No data are available.' Verify any paediatric dose against a children's formulary.

Dose adjustments

Renal

No dose adjustment. UK SPC §4.2 (both indications): 'Renal and hepatic impairment: GlucaGen can be used in patients with renal and hepatic impairment.' §4.8 adds that the frequency, type and severity of adverse reactions in patients with renal or hepatic impairment 'are expected to be the same as in the general population.'

Hepatic

No dose adjustment is stated - UK SPC §4.2: 'GlucaGen can be used in patients with renal and hepatic impairment.' But efficacy is conditional: §4.4 'Glucagon will not be effective in patients whose liver glycogen is depleted. For that reason, glucagon has little or no effect when the patient has been fasting for a prolonged period, or is suffering from adrenal insufficiency, chronic hypoglycaemia or alcohol induced hypoglycaemia.' The US label agrees: 'Glucagon for Injection is effective in treating hypoglycemia only if sufficient hepatic glycogen is present. Patients in states of starvation, with adrenal insufficiency or chronic hypoglycemia may not have adequate levels of hepatic glycogen... Patients with these conditions should be treated with glucose.'

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — clinician-reviewed. 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

  • UK SPC §4.3, verbatim: 'Hypersensitivity to the active substance or to any of the excipients listed in section 6.1.'
  • UK SPC §4.3, verbatim: 'Phaeocromocytoma' [phaeochromocytoma] - §4.4 explains: 'In the presence of phaeocromocytoma, glucagon can cause the tumour to release large amounts of catecholamines, which will cause an acute hypertensive reaction.'
  • US label §4: insulinoma, 'because of the risk of hypoglycemia'. In the UK SPC this is a §4.4 caution rather than a contraindication - 'Glucagon reacts antagonistically towards insulin and caution should be observed if GlucaGen is used in patients with insulinoma.'
  • US label §4: glucagonoma 'when used as a diagnostic aid because of the risk of hypoglycemia'. The UK SPC states this as a caution: 'Caution should be observed in patients with glucagonoma when used as diagnotic aid.'
  • US label §4: known hypersensitivity to glucagon or any of the excipients - 'Allergic reactions have been reported with glucagon and include anaphylactic shock with breathing difficulties and hypotension.'

Side effects

  • UK SPC §4.8 summary: 'Severe adverse reactions are very rare, although nausea, vomiting and abdominal pain may occur occasionally.'
  • Therapeutic indication - common (>=1/100 to <1/10): nausea. Uncommon (>=1/1,000 to <1/100): vomiting. Rare (>=1/10,000 to <1/1,000): abdominal pain (UK SPC §4.8 table)
  • Very rare (<1/10,000), UK SPC §4.8: hypersensitivity reactions including anaphylactic reaction/shock
  • Frequency not known, UK SPC §4.8: injection site reactions
  • Diagnostic indication only, UK SPC §4.8: hypoglycaemia (uncommon) and hypoglycaemic coma (very rare), especially in patients who have fasted; tachycardia, hypotension and hypertension (very rare) - 'Cardiovascular adverse events, such as tachycardia and blood pressure changes have only been reported when GlucaGen is used as an adjunct in endoscopic or radiographic procedures.'
  • US label §6 post-approval reports: injection site reactions including erythema and swelling, nausea, vomiting, headache, dizziness, asthenia, pallor, diarrhoea, somnolence, generalised allergic reactions including anaphylactic shock with breathing difficulties and hypotension, hypertension and tachycardia, decreased blood pressure (hypotension reported up to 2 hours after administration as premedication for upper GI endoscopy), and hypoglycaemia / hypoglycaemic coma
  • US label §5: necrolytic migratory erythema; hyperglycaemia in patients with diabetes mellitus when used as a diagnostic aid; blood pressure and heart rate increase in patients with cardiac disease when used as a diagnostic aid
  • UK SPC §4.8 paediatric population: 'the frequency, type and severity of adverse reactions observed in children are expected to be the same as in adults'

Monitoring

  • Response and blood glucose: UK SPC - 'The patient will normally respond within 10 minutes'; if there is no response within 10 minutes, intravenous glucose should be given.
  • After recovery: UK SPC - 'When the patient has responded to the treatment, give oral carbohydrate to restore the liver glycogen and prevent relapse of hypoglycaemia.' US label: give oral carbohydrates once the patient is able to swallow.
  • UK SPC §4.4 (diagnostic use): 'GlucaGen may increase myocardial oxygen demand, blood pressure, and pulse rate. Monitor patients with cardiac disease during use of GlucaGen as a diagnostic aid and treat if indicated.'
  • UK SPC §4.4 (diagnostic use): 'GlucaGen may cause short term hyperglycaemia in patients with diabetes mellitus when used as a diagnostic aid. Monitor patients with diabetes for changes in blood glucose levels during use and treat if indicated.'
  • US label §7 interactions: with indomethacin, 'Monitor blood glucose levels during glucagon treatment'; with warfarin, 'Monitor patients for unusual bruising or bleeding, as adjustments in warfarin dosage may be required'; with beta-blockers, a transient increase in pulse and blood pressure may occur and 'may require therapy in patients with coronary artery disease'.
  • UK SPC §4.4 traceability: 'the name and the batch number of the administered product should be clearly recorded.'

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).

Related

Curated clinical cross-links plus same-class fallbacks.

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