Print This Post
Many times throughout the Paramedic Program I have come across a drug that has an unexpected use listed in the profile. Not very often are we given a comprehensive explanation as to why this drug works for this other use and it is left to us to try and figure this out. One example that I have seen recently is the use of Glucagon for beta blocker overdose. Glucagon is a hormone used in diabetic emergencies; its use for beta blocker overdose is actually pretty simple once it is explained.
Glucagon – Profile
Glucagon is a hormone produced by the alpha cells in the pancreas, it is opposed by insulin, a hormone produced by the beta cells in the pancreas. During periods of low blood sugar, for example, between meals, glucagon is secreted into the bloodstream which then begins the process of breaking down glycogen stores in the liver and muscle (glycogenolysis) to increase available blood glucose. After meals and at time of increased blood sugar, insulin is secreted to allow the cells to take up circulating glucose and stimulate the formation of glycogen (glycogenesis). Glucagon is also released during periods of stress to increase available energy during the fight or flight response. Additionally, glucagon possesses an inotropic quality, increasing the contractility of the myocardium thereby increasing stroke volume and cardiac output.
Glucagon – Use in Emergency Medicine
As an emergency drug, glucagon is administered to patients in severe hypoglycemia/insulin shock where IV access is unavailable. The expected response takes around 10 minutes to start and will only work if the patient has adequate glycogen stores available. This will not work for starving patients and alcoholics. The dose is 1mg IM.
Its use for beta blocker and calcium channel blocker overdose relies on its inotropic properties. Being that the beta adrenergic receptors are being blocked, epinephrine cannot exert its inotropic effect on the heart. Glucagon, in high doses (initial dose of 3-5mg IV) may have enough of an inotropic effect to increase cardiac output and blood pressure. For CCB overdoses it works the same way, just this time it the calcium channels that are blocked which also cause reduced contractility.
Glucagon is also used in cases of anaphylactic shock when epinephrine is not working (usually due to beta blocker use). The dose in this case would be 1-2mg IV over 5 minutes.
Hope it’s clear now, worked for me 
