Glucagon is a polypeptide hormone normally produced by the alpha cells of the pancreas. Parenteral administration results in release of glucose by the breakdown of glycogen and inhibition of its formation, primarily in the liver. It can be helpful for the rapid reversal of coma due to severe hypoglycemia.


1 international unit (IU) = 1 mg


Route of administration: intravenous (IV), intramuscular (IM) or subcutaneous (SC)


The IV route has the fastest onset of action (about one minute) but also the shortest duration of action (as short as 10 minutes). The IM route has an onset of 5-10 minutes and a duration of 15 to 30 minutes, depending on the dose.



(1) 0.25 to 0.5 units for pediatric patients weighing less than 20 kg (44 lbs)

(2) 1 unit for adults or pediatric patients weighing more than 20 kg

(3) 2 units may be considered for a larger adult for whom intravenous access cannot be established


A source of glucose (oral feeding once awake, an intravenous infusion) should be started in order to provide glucose once the glucagons effect wears off.


Failure to reverse hypoglycemia may occur in:

(1) depleted glycogen stores in the liver (as in severe malnutrition)

(2) overdose of sulfonylureas

(3) adrenal insufficiency


Rebound hypoglycemia may occur in:

(1) patients with an insulinoma (due to release of insulin from the tumor)

(2) failure to administer glucose concurrently (as glycogen stores become depleted)


Other complications:

(1) severe hypertension in a patient with a pheochromocytoma

(2) dose-dependent nausea and vomiting

(3) allergic reactions


The reason for the hypoglycemia needs to be identified so that it can be prevented in the future.


To read more or access our algorithms and calculators, please log in or register.