Glucagon

Summary

Glucagon is a 29-amino acid pancreatic hormone produced by alpha cells of the islets of Langerhans. It is approved for emergency treatment of severe hypoglycemia in patients with diabetes and as a diagnostic aid to inhibit GI motility. It serves as the physiological counterpart to insulin.

Mechanism of Action

Binds and activates glucagon receptors (GCGRs) on hepatocytes, stimulating glycogenolysis and gluconeogenesis via cAMP/PKA signaling, thereby raising blood glucose. Also relaxes gastrointestinal smooth muscle and stimulates insulin secretion at high doses.

Routes of Administration

Goals & Uses

• Diagnostic GI motility inhibitionGastroenterology / DiagnosticsHigh
• Insulinoma localizationEndocrinology / DiagnosticsModerate
• Pheochromocytoma diagnosisEndocrinology / DiagnosticsModerate
• Severe hypoglycemia rescueGlycemic Emergency ManagementHigh
• Beta-blocker overdose managementToxicology / EmergencyModerate

Contraindications

• Hypersensitivity to glucagon or excipientsImmunology / AllergyHigh
• InsulinomaEndocrine TumorHigh
• PheochromocytomaEndocrine TumorHigh
• Starvation or adrenal insufficiencyMetabolic / EndocrineModerate
• GlucagonomaEndocrine TumorHigh

Adverse Effects

• Rebound hypoglycemiaMetabolic / EndocrineUncommon
• HypokalemiaElectrolyteUncommon
• Hypersensitivity / anaphylaxisImmunologicalRare
• Injection site reactionsLocalCommon
• Nausea and vomitingGastrointestinalCommon
• Tachycardia / hypertensionCardiovascularUncommon

Drug Interactions

• Beta-adrenergic blockersLow
• InsulinModerateMay increase risk of low blood sugar
• IndomethacinLow
• Warfarin / anticoagulantsModerate

Population Constraints

• PregnancyReproductive SafetyRelative
• Pediatric patients (neonates/infants)PediatricRelative
• Chronic starvation / malnutritionMetabolicRelative
• Renal or hepatic impairmentOrgan DysfunctionRelative

Regulatory Status

• European UnionApprovedApproved: Severe hypoglycemia, Diagnostic aid for GI motility inhibitionGlucaGen approved by EMA; Baqsimi (nasal powder) also approved in EU.
• United StatesApprovedApproved: Severe hypoglycemia in diabetes (IM, SC, IV, intranasal), Diagnostic aid to inhibit GI motility (IV, IM)GlucaGen (Novo Nordisk) and Glucagon Emergency Kit (Eli Lilly) FDA-approved; Baqsimi (nasal powder) FDA-approved 2019. Gvoke (glucagon injection) also approved.
• United KingdomApprovedApproved: Severe hypoglycemia, Diagnostic GI relaxationMHRA-approved; available as GlucaGen HypoKit and Baqsimi nasal powder.

Approved by the FDA as GlucaGen (Novo Nordisk) and Glucagon Emergency Kit (Eli Lilly). A nasal powder formulation (Baqsimi, Eli Lilly) is also FDA-approved. EMA approval exists for similar indications in the EU.

Evidence & Sources

No sources recorded yet.