Glucagon

Glucagon is the native 29-amino-acid pancreatic hormone that raises blood glucose. The injection is FDA-approved for symptomatic Paget's disease-unrelated emergencies — specifically for severe hypoglycemia — and, intravenously, as a diagnostic aid to temporarily inhibit gastrointestinal motility during radiologic examinations in adults. Available products include ready-to-use subcutaneous injections, a nasal powder, and traditional lyophilized emergency kits, each with different indications, routes and age cut-offs.

Glucagon binds hepatic glucagon receptors and stimulates the breakdown of stored glycogen, releasing glucose into the bloodstream and opposing the action of insulin. It also relaxes gastrointestinal smooth muscle, which is the basis for its separate use as a diagnostic aid during radiologic procedures.

Yes. Glucagon is approved by the U.S. FDA and has official prescribing information. Evidence level: approved labeling. Official prescribing information exists, based on clinical trials in people.

Reported half-life: Short — approximately 32 minutes reported for the ready-to-use subcutaneous injection in adults with type 1 diabetes. Published values vary by route and assay; one secondary source reports approximately 42 minutes subcutaneously and 26 minutes intramuscularly, and the discrepancy is unresolved.

Subcutaneous or intramuscular injection, intranasal powder, or intravenous injection for diagnostic use. The glucose-raising effect is transient, so oral carbohydrate must be given once the person is able to swallow, and emergency assistance should be summoned for any episode of severe hypoglycemia.

Reported in the sources: Contraindicated in pheochromocytoma, because glucagon may stimulate catecholamine release from the tumor and cause a substantial increase in blood pressure; Contraindicated in insulinoma, where an initial rise in blood glucose can provoke exaggerated insulin release and subsequent hypoglycemia; the intravenous diagnostic formulation is additionally contraindicated in glucagonoma, also because of the risk of hypoglycemia; Contraindicated in anyone with a prior hypersensitivity reaction to glucagon or to any excipient in the product. Serious hypersensitivity reactions have been reported with glucagon, including generalized rash and anaphylactic shock with breathing difficulty and hypotension; Ineffective when hepatic glycogen is inadequate, including in states of starvation, adrenal insufficiency or chronic hypoglycemia; these situations require glucose rather than glucagon; Necrolytic migratory erythema, a scaly, itchy rash with plaques, bullae and erosions, has been reported with continuous glucagon infusion, not with single emergency doses; Nausea, vomiting, headache and injection site edema are common with subcutaneous use; intravenous diagnostic use commonly causes nausea, dysgeusia, headache, hot flush and dizziness, can raise blood pressure and heart rate in people with cardiac disease, and can cause hyperglycemia in people with diabetes.