Glucagon is a hormone that plays an important role in maintaining stable blood sugar levels. It acts to increase blood glucose when levels drop too low, a condition known as hypoglycemia. For individuals managing diabetes, especially those who use insulin, glucagon is a treatment used in emergency situations to rapidly raise dangerously low blood sugar. Its swift action can prevent severe complications.
How Glucagon Works
Glucagon is a hormone created by alpha cells within the pancreas. It counteracts insulin, preventing blood glucose from falling to unsafe levels. When blood sugar is low, glucagon signals the liver to release stored glucose (glycogenolysis) and create new glucose from other sources, such as amino acids (gluconeogenesis). This glucose then enters the bloodstream, raising blood sugar. It binds to specific receptors on liver cells, initiating a signaling cascade that increases glucose production and release.
Typical Speed of Action
Glucagon acts quickly to raise blood sugar levels. When administered, blood glucose typically begins to rise within 5 to 10 minutes. Onset speed varies by administration method.
Intravenous (IV) administration can show effects faster (1-3 minutes), with maximum glucose reached within 5-20 minutes. For intramuscular (IM) injections, common in emergency settings, peak effect is generally observed around 20 to 30 minutes. Intranasal formulations also demonstrate a rapid onset, with peak concentration often attained within 15 to 20 minutes for adults. Glucagon’s action typically lasts 60 to 90 minutes.
Factors Affecting Speed
Several factors influence glucagon’s speed and effectiveness. Administration method plays a role, with intravenous delivery providing the fastest response compared to intramuscular, subcutaneous, or intranasal routes. Physiological state is also significant; glucagon’s effectiveness relies on adequate liver glycogen stores. If these stores are depleted (e.g., after prolonged fasting, strenuous exercise, or malnutrition), glucagon may be less effective or take longer to work.
Severity of hypoglycemia also impacts response time; rapidly dropping blood glucose might outpace glucagon’s action. High levels of insulin (“insulin-on-board”) can reduce or negate glucagon’s effects. Proper administration technique, especially for devices requiring mixing or specific injection methods, is important for effectiveness.
When Glucagon Is Administered
Glucagon is used for severe hypoglycemia, especially when an individual cannot consume carbohydrates by mouth or has lost consciousness. It is also indicated for seizures due to extremely low blood sugar. Though often associated with unconsciousness, glucagon can be administered for severe low blood sugar events that impair physical or mental function.
After administering glucagon, call for emergency medical assistance. If unconscious, turn the person onto their side to reduce choking risk from vomiting, a common side effect. Consciousness is typically regained within 15 minutes. If no response within this timeframe, a second dose may be given while awaiting emergency personnel. Once awake and able to swallow, give a fast-acting sugar, followed by a longer-acting carbohydrate to stabilize blood glucose and prevent recurrence.