Glucagon

Glucagon

Glucagon, a hyperglycemic drug that raises blood glucose levels,is a hormone normally produced by the alpha cells of the islets ofLangerhans in the pancreas. (See How glucagon raises glucoselevels)

Pharmacokinetics

After subQ, I.M., or I.V. injection, glucagon is absorbed rapidly.Glucagon is distributed throughout the body, although its effectoccurs primarily in the liver.

Metabolism and excretion

Glucagon is degraded extensively by the liver, kidneys, and plas-ma, and at its tissue receptor sites in plasma membranes. It’s re-moved from the body by the liver and the kidneys.

Pharmacodynamics

Glucagon regulates the rate of glucose production through:

• glycogenolysis, the conversion of glycogen back into glucose by the liver

• gluconeogenesis, the formation of glucose from free fatty acids and proteins

• lipolysis, the release of fatty acids from adipose tissue for conversion to glucose.

Pharmacotherapeutics

Glucagon is used for emergency treatment of severe hypoglycemia. It’s also used during radiologic examination of the GI tract toreduce GI motility.

Drug interactions

Glucagon interacts adversely only with oral anticoagulants, increasing the tendency to bleed. Adverse reactions to glucagon are rare.