Glucagon
Polypeptide hormone (29 amino acids)
Also known as: GlucoGen · GlucaGen HypoKit · Glucagon Emergency Kit · glucagonum · HGF
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Audited v13 dosing evidence
Reviewed non-calculator evidenceReviewed non-calculator evidence (1)
Evidence only — not for automatic calculation
Insulinoma hypoglycemic crisis with insufficient response to other therapy
Glucagon 15–40 ng/kg/min CRI (constant rate infusion)
Governing clinical context (1)
- may be helpful in animals with an insufficient response to other types of therapy
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Glucagon is a vital counter-regulatory polypeptide hormone naturally secreted by the alpha-2 cells of the pancreas. In veterinary medicine, it serves as a critical emergency and critical care drug.
- Primary Use: Rapidly increases blood glucose levels in patients suffering from severe hypoglycemia, particularly due to insulinoma (endogenous insulin excess) or insulin overdose (exogenous excess).
- Large Animal Application: Shows potential for treating fatty liver syndrome (hepatic lipidosis) in dairy cattle.
- Toxicology: While used in human medicine for beta-blocker and calcium-channel blocker overdoses, veterinary studies (e.g., in dogs) suggest high-dose insulin therapy may be superior for propranolol toxicity.
Clinical Pearl: Glucagon relies on adequate hepatic glycogen stores to be effective. In severely emaciated or cachectic patients with depleted glycogen, its efficacy may be significantly blunted.
Mechanism of action
Glucagon acts as a physiological antagonist to insulin, primarily targeting the liver to increase blood glucose levels.
- Binds to specific glucagon receptors (GPCRs) on the surface of hepatocytes.
- Activates adenylate cyclase → increases intracellular cAMP → activates protein kinase A (PKA).
- This cascade stimulates glycogen phosphorylase and inhibits glycogen synthase, leading to rapid hepatic glycogenolysis (breakdown of stored glycogen into glucose) and gluconeogenesis.
- Also causes relaxation of gastrointestinal smooth muscle through poorly understood mechanisms (likely cAMP-mediated).
Safety & warnings
Contraindications
- Normoglycemia
- Pheochromocytoma (in humans)
- Insulinoma (may stimulate insulin release)
Adverse effects
- Nausea
- Hypokalemia
- Hypersensitivity reactions (very rare)
- Vomiting (main adverse reaction reported in humans)
- Anaphylaxis (rare)
Precautions
Pheochromocytoma Warning: Glucagon should usually not be used in patients with pheochromocytoma as catecholamines may be released leading to hypertension.
- Insulinoma Caution: When used for insulinoma, it must be in a setting where blood glucose can be closely monitored. It can stimulate insulin production, potentially leading to greater rebound hypoglycemia once the drug is discontinued.
- Pregnancy/Nursing: FDA Category B in humans. As an endogenously produced hormone, it is unlikely to cause significant risk to offspring or nursing young.
Drug interactions
May have their effects increased when glucagon is concurrently administered; this effect may be delayed. Monitor for bleeding and prothrombin activity.
Monitoring
- Serum potassium (if used other than for acute treatment)
- Blood glucose (hourly)
- Serum potassium (if prolonged infusion)
Pharmacokinetics
Half-life
Absorption
Must be administered parenterally; destroyed in the gut after oral dosing. After IV injection, maximum glucose levels are attained within 30 minutes; hyperglycemic effects persist up to 90 minutes.
Distribution
Distributes to target organs, primarily the liver.
Metabolism
Degraded in the plasma, liver, and kidneys.
Elimination
Rapidly cleared from circulation.
Overdose
Adverse effects seen with overdose include nausea, vomiting, diarrhea, gastric hypotonicity and, possibly, hypokalemia.
- Because glucagon's elimination half-life is so short (around 10 minutes in humans), treatment may not be necessary and would be symptomatic in nature.
- If the patient is also receiving beta-blockers, greater increases in blood pressure and heart rate may be seen.
Available products
Formulations
- Powder for injection
- 1 mg vial for reconstitution (Injectable)
Human-labeled
- Glucagon Powder for Injection: 1 mg (1 unit) with 1 mL diluent in vials & syringes
- GlucaGen Diagnostic Kit
- GlucaGen HypoKit
- Glucagon Emergency Kit
- Glucagen 1 mg vial for reconstitution
Regulatory status
Human authorized product used off-label under the cascade.
POM (Prescription Only Medicine)
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store commercially available powder for reconstitution at room temperature between 20-25°C (68-77°F); avoid freezing and protect from light. Once reconstituted with the supplied diluent, the solution should be clear with a water-like consistency and used immediately; discard any unused portion. Discard if the solution contains any gel formation or particles.
Client information
Emergency Use Only: Glucagon is typically administered in a hospital setting where your pet's blood sugar can be continuously monitored.
- At-Home Hypoglycemia: While glucagon could potentially be used for outpatient emergency initial treatment of severe low blood sugar, oral glucose syrups (like Karo syrup) rubbed on the gums are generally more practical and appropriate for pet owners to use at home.
- Monitoring: If your pet is hospitalized and receiving a continuous infusion of glucagon, the veterinary team will closely monitor their blood glucose and potassium levels.
- Side Effects: It is generally very safe and well-tolerated, but mild nausea or vomiting may occasionally occur.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.