Glucagon

A to Z Drug Facts

 Action Elevates blood glucose concentrations (by stimulating production from liver glycogen stores), relaxes smooth muscle of GI tract, decreases gastric and pancreatic secretions in GI tract, and increases myocardial contractility.

 Indications Treatment of severe hypoglycemic reactions in diabetic patients when glucose administration is not possible or during insulin shock therapy in psychiatric patients; diagnostic aid in radiologic examination of stomach, duodenum, small bowel, and colon when diminished intestinal motility would be advantageous. unlabeled use(s): Treatment of propranolol overdose, cardiovascular emergencies, and GI disturbances associated with spasms.

 Contraindications Standard considerations.

 Route/Dosage

Hypoglycemia

ADULTS & CHILDREN > 20 kg: SC/IM/IV 1 mg (1 unit). Do not use glucagon at concentrations > 1 mg/mL (1 unit/mL). CHILDREN < 20 kg: SC/IM/IV 0.5 mg (0.5 unit) or a dose equivalent to 20 to 30 mcg/kg.

Insulin Shock Therapy

ADULTS: SC/IM/IV 0.5 to 1 mg after 1 hr of coma (larger doses have been used to reverse coma). Patient will usually awaken in 10 to 25 min. If no response, may repeat dose.

Diagnostic Aid

ADULTS & CHILDREN: IM/IV 0.25 to 2 mg depending on procedure and desired length of smooth muscle relaxation.

 Interactions

Anticoagulants, oral: May increase hypoprothrombinemic effects, possibly with bleeding.

 Lab Test Interferences None well documented

 Adverse Reactions

GI: Nausea; vomiting. OTHER: Generalized allergic reactions, including urticaria, respiratory distress, and hypotension.

 Precautions

Pregnancy: Category B. Lactation: Undetermined. Insulinoma/pheochromocytoma: Administer cautiously to patient with history of insulinoma or pheochromocytoma or both. Hypoglycemia: Glucagon is effective in treating hypoglycemia only if sufficient liver glycogen is present. Because glucagon is of little or no help in states of starvation, adrenal insufficiency, or chronic hypoglycemia, treat hypoglycemia in these conditions with glucose.

 Administration/Storage

• Separate vial of diluting solution is supplied with vial of glucagon crystals. After dilution, solution should be clear; discard if not clear.
• Administer glucose orally, IV, or by gavage to a patient developing symptoms of hypoglycemia after a dose of glucagon.
• To control sudden increases in blood pressure, 5 to 10 mg of IV phentolamine mesylate may be administered.
• After reconstitution, use solution immediately. Discard any unused portion.
• Position patient on side during administration.
• Treat severe hypoglycemia initially with IV glucose; if this is not possible, prepare parenteral glucagon and use immediately. Patient will usually awaken within 15 min. If response is delayed, administer additional dose of glucagon and seek emergency aid. After patient responds, give supplemental carbohydrate to restore liver glycogen and to prevent secondary hypoglycemia.
• If necessary, solution may be refrigerated for 48 hr after dilution. Date vial if it is to be used for multiple doses.
• Store unopened vials at room temperature.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies. Note diabetes mellitus.
• Obtain blood glucose determinations in a hypoglycemic patient until the patient is asymptomatic.
• Assess patient's level of compliance with regimen of diabetes control and level of understanding. Obtain family input if patient is unable or unwilling to give this information.
• Initiate safety precautions to prevent injury caused by seizures, falling, or aspiration.
• In event of vomiting when neurologic status is decreased, institute measures to maintain patent airway.
• Use fingerstick blood level test to quickly determine glucose level.
• Administer supplemental oral sources of carbohydrates if patient is alert and oriented and does not exhibit any swallowing difficulties.
• Assess for signs and symptoms of hypoglycemic reactions: Neurologic alterations, sweating, hunger, weakness, headache, dizziness, tremor, irritability, tachycardia, anxiety.
• Assess blood glucose levels before, during, and after administration.
• Assess for nausea and vomiting. Notify health care provider if vomiting occurs.
• Decreased serum potassium concentration may occur with overdosage. Normal limits can be obtained with potassium supplementation. IV administration has demonstrated positive inotropic and chronotropic effects. A transient increase in BP and pulse rate may occur. Patients receiving beta-blockers may be expected to have a greater increase in blood pressure and pulse. Patients with pheochromocytoma and coronary artery disease may require therapy for increased BP and pulse rate.
• Because glucagon is a polypeptide, it would be rapidly destroyed by the GI tract if it were to be accidently ingested.

 Patient/Family Education

• Review with patient and family correct technique for administering IV injections.
• Refer patients and family to the patient information supplied with the product.
• Teach importance of early recognition and treatment of hypoglycemia. Inform patient about immediate use of oral carbohydrates and how to evaluate effectiveness. Teach importance of obtaining fingerstick blood level as soon as feasible.
• Instruct patient to obtain glucagon emergency kit. Instruct family about glucagon administration technique in presence of swallowing difficulties or other neurologic symptoms. Explain importance of notifying health care provider of such symptoms.
• Tell family to turn patient on side if patient loses consciousness.
• Advise family to administer food to patient after consciousness and swallowing function return.
• Teach patient ways to prevent hypoglycemia (eg, medication administration, dietary modifications, activity, frequent testing, and routine carrying of candy) and measures to institute in event of acute illness. Inform patient and family of the symptoms of mild hypoglycemia and to arouse patient as quickly as possible because prolonged hypoglycemia may result in CNS damage. Advise patient to inform health care provider when hypoglycemia reactions occur.
• Emphasize importance of checking medication expiration dates monthly and having sufficient medication on hand.
• Instruct patient to carry medical history identification and quick source of carbohydrates at all times.

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Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts