Glucagon

Glucagon contains 29 amino acids and raises glucose in opposition to insulin’s glucose-lowering action. It is used for severe hypoglycemia, especially in insulin-treated diabetes, when the person cannot safely eat or drink. Products include ready-to-use Gvoke and nasal Baqsimi; the US GlucaGen HypoKit emergency kit was discontinued in 2024.

Supporting references: discontinued; Gvoke; Baqsimi.

Binding hepatic glucagon receptors promotes glycogen breakdown and new glucose production, raising circulating glucose within minutes. Its rescue effect can be reduced after prolonged fasting or starvation because liver glycogen stores may be depleted. It also relaxes gastrointestinal smooth muscle, explaining certain hospital imaging uses. A trial in adults with type 1 diabetes found nasal powder raised glucose approximately as effectively as injected glucagon, without emergency mixing or a needle.

Supporting references: glucose.

A caregiver can give the prescribed rescue product when severe hypoglycemia prevents safe oral sugar intake. Injectable products can also be used to relax the gut for radiologic procedures. Glucagon is contraindicated in pheochromocytoma and insulinoma; rescue and diagnostic products should retain their specific instructions rather than being treated as one generic administration method.

Nausea, vomiting and headache are reported. Injection reactions occur with injectables, while nasal/eye symptoms can occur with powder. Pheochromocytoma can produce a marked blood-pressure rise, and insulinoma can cause rebound hypoglycemia. Rare allergic reactions are another serious concern.