Glucagon is a hormone that elevates glucose (blood sugar), the body’s main source of energy. Available as a prescription drug, glucagon can be injected to avoid the consequences of severe insulin-induced hypoglycemia or insulin shock.

Glucagon is produced naturally by the alpha cells in the pancreas. It causes the release of stored carbohydrates(glycogen) from the liver into the bloodstream, which raises glucose levels. In effect, glucagon is the opposite of insulin, a natural hormone that helps to lower glucose levels in the bloodstream.

All patients with type 1 diabetes, and some with type 2 diabetes, take insulin to prevent excess glucose (hyperglycemia). When too much insulin is present, glucose levels can drop too low, causing symptoms of hypoglycemia.

Hypoglycemia can be caused by several factors, including:

• Excess amounts of insulin or antidiabetic agents
• Not eating enough calories
• Sudden, intense physical exertion
• Sickness, especially with vomiting and diarrhea
• Excessive drinking of alcohol

Hypoglycemia should be treated according to the diabetes treatment plan devised by the individual's physician. For example, it can be treated early by consuming a fast-acting carbohydrate, such as fruit juice, soda (not the sugar-free variety), glucose tablets or hard candies. Glucagon injections or other emergency treatment, such as intravenous glucose, become necessary when blood glucose levels become dangerously low and oral treatment is no longer an option (due to loss of consciousness, for instance).

The American Diabetes Association (ADA) cautions that glucagon does not treat hypoglycemia caused by drinking alcohol because alcohol keeps the liver from releasing glucose. People who lose consciousness because of alcohol need a glucose injection from a health professional, according to the ADA. Nor does glucagon work well if hypoglycemia is chronic or is due to starvation or adrenal insufficiency (e.g., Addison’s disease), according to the U.S. Food and Drug Administration. These cases should also be remedied with glucose, the agency advises.

Glucagon comes in a kit that lasts for about six months before its effectiveness expires. These kits contain:

• A vial of powder containing freeze-dried glucagon
• A syringe filled with glycerin liquid to mix with the medicine

When glucagon is injected it forces the liver to produce a quick burst of sugar into the bloodstream. It also raises blood glucose levels by preventing the liver from storing glucose and increasing glucose formation in the liver from dietary proteins and fats. Glucagon can boost blood glucose levels by 20 to 30 milligrams per deciliter (mg/dL) within minutes.

Patients should practice regular glucose monitoring as advised by their physician. A low blood glucose reading is any reading below a patient’s recommended target range. Individuals should discuss in advance with their physician what steps to take at various irregular glucose levels.

The U.S. government’s National Diabetes Information Clearinghouse recommends that patients ask their healthcare provider if they should keep a glucagon kit at home and at work and, if this is advised, that their family, friends and coworkers be trained in how to inject glucagon in an emergency. The National Diabetes Education Program suggests that people who use insulin also pack a glucagon kit when traveling. The ADA reports that increasing numbers of school districts and states are training teachers, bus drivers and other nonmedical personnel to inject glucagon when a school nurse in not available.

Immediate action is required when a person experiences a bout of severe hypoglycemia. National diabetes organizations recommend that bystanders should immediately call for emergency medical help (phoning 911 in the United States and some other countries) and, if the victim is not conscious, not to try to give the patient food or drink. Trained individuals can prepare and deliver a glucagon injection.

Additional recommendations include that before an injection is given, the patient should be laid on one side to reduce the risk of choking. Glucagon can cause severe nausea, and vomiting is not uncommon.

General guidelines for preparing and administering an injection of glucagon are available from the manufacturer or pharmacist, including preparing, drawing up and injecting the glucagon solution.  

The dosage for glucagon is different for different patients. Individuals should follow the dosage on the kit or physician’s orders if included with the medication. A typical glucagon dosage for emergency treatment:

• Adults and children weighing 44 pounds (20 kilograms [kg]) or more: 1 mg
  
  
• Children weighing up to 44 pounds (20 kg): 0.5 mg or 20 to 30 micrograms (mcg)

With adults and children, the dose can be repeated after 15 minutes if necessary.

According to the manufacturer, any medication that has been mixed but not used should be discarded once the patient has recovered consciousness. The patient’s glucose should be checked at least once an hour for three or four hours after consciousness has been regained.