Known brand names include GlucaGen.
An emergency shot for severe low blood sugar in people with diabetes, usually given by a family member or caregiver because the person is too low to treat themselves. It makes the liver release stored sugar, and it is also used in imaging to hold the gut still for X-ray exams.
Labeled use. Treatment of severe hypoglycemia in adults and children with diabetes.
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For a conscious person who can swallow, oral fast-acting carbohydrate comes first. Glucagon is the choice when the person cannot safely take sugar by mouth and no IV is available, because a trained family member can give it. With IV access, IV dextrose is preferred: it acts at once and does not depend on liver glycogen, so it is needed in starvation, adrenal insufficiency, or heavy alcohol use. Nasal and ready-to-use glucagon are easier for caregivers but are outside this record. High-dose glucagon for beta-blocker or calcium channel blocker overdose is an off-label teaching point, not a labeled use.
Synthetic glucagon, a 29-amino-acid peptide identical to human glucagon. It activates hepatic glucagon receptors, which stimulates glycogenolysis and hepatic glucose release, so it works only when liver glycogen stores are adequate. Outside the liver it relaxes smooth muscle in the stomach, duodenum, small bowel, and colon. After 1 mg subcutaneously, glucose rises within 10 minutes and peaks at about 30 minutes; the half-life is 8 to 18 minutes.
The label does not describe a narrow therapeutic index or direct dosing by measured blood levels of the drug.
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Doses come from the FDA label. Study tool, not for clinical decisions.
No renal dose adjustment on the label. Glucagon is degraded in the liver, kidney, and plasma.
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No specific antidote. Overdose can cause nausea, vomiting, slowed GI motility, and a rise in blood pressure and pulse; serum potassium may fall, so check and correct it. For a dramatic blood pressure rise, IV phentolamine has lowered pressure effectively for the short period control is needed.
Decades of case reports and small observational studies have not linked glucagon to major birth defects, miscarriage, or other poor maternal or fetal outcomes. Small studies found that pancreatic glucagon does not cross the placenta in early pregnancy, and rat studies at up to 40 times the human dose showed no embryofetal harm.
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No data on glucagon in human or animal milk, on the breastfed infant, or on milk production. Because it is a peptide, it would be digested into amino acids in the infant's gut and is unlikely to cause harm.
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Labeled for severe hypoglycemia in children with diabetes. Under 20 kg: 0.5 mg (0.5 mL), or 20 to 30 mcg/kg, SC, IM, or IV, with one more 0.5 mg dose after 15 minutes if there is no response. 20 kg or more: the 1 mg adult dose. Safety and effectiveness as a diagnostic aid in children have not been established.
Studies did not include enough people 65 and older to show a difference, and other clinical experience has not found one. For diagnostic-aid use, start at the low end of the dose range because liver, kidney, or heart disease and other medicines are more common.
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