glucagon

Stimulates hepatic production of glucose from glycogen stores (glycogenolysis).
Relaxes the musculature of the GI tract (stomach, duodenum, small bowel, and colon), temporarily inhibiting movement.
Has positive inotropic and chronotropic effects.

Therapeutic effects:

Increase in blood glucose.
Relaxation of GI musculature, facilitating radiographic examination.

Pharmacokinetics ⬆ ⬇

Absorption: Well absorbed following IM, intranasal, and SUBQ administration; IV administration results in complete bioavailability.

Distribution: Extensively distributed to tissues.

Metabolism/Excretion: Extensively metabolized by the liver, plasma, and kidneys.

Half-Life: 8–18 min.

Time/Action Profile ⬆ ⬇

ROUTE	ONSET	PEAK	DURATION
IM (hyperglycemic action)	within 10 min	30 min	12–27 min
IV (hyperglycemic action)	1 min	5 min	9–17 min
SUBQ (hyperglycemic action)	within 10 min	30–45 min	60–90 min
Intranasal (hyperglycemic action)	within 15 min	unknown	unknown
IV (effect on GI musculature)	45 sec (for 0.25–2-mg dose)	unknown	9–17 min (0.25–0.5-mg dose); 22–25 min (2-mg dose)
IM (effect on GI musculature)	8–10 min (1-mg dose); 4–7 min (2-mg dose)	unknown	9–27 min (1-mg dose); 21–32 min (2-mg dose)

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Pheochromocytoma;
Insulinoma.

Use Cautiously in:

Prolonged fasting, starvation, adrenal insufficiency, or chronic hypoglycemia (low levels of releasable glucose);
OB: Use during pregnancy only if potential maternal benefit justifies potential fetal risk;
Lactation: Safety not established in breastfeeding;
Pedi: Children 4 yr (safety and effectiveness of nasal powder not established).

Adv. Reactions/Side Effects ⬆ ⬇

CV: hypotension

Derm: necrolytic migratory erythema

EENT: epistaxis, eye redness, itchy eyes, itchy throat, nasal congestion, nasal discomfort, nasal itching, rhinorrhea, sneezing, watery eyes

GI: nausea, vomiting

Neuro: headache

Resp: cough

Misc: HYPERSENSITIVITY REACTIONS (INCLUDING ANAPHYLAXIS)

Interactions ⬆ ⬇

Drug-drug:

Large doses may ↑ the effect of warfarin.
Negates the response to insulin or oral hypoglycemic agents.
Phenytoin inhibits the stimulant effect of glucagon on insulin release.
Hyperglycemic effect is intensified and prolonged by epinephrine.
Patients on concurrent beta blocker therapy may have a greater ↑ in heart rate and BP.

Route/Dosage ⬆ ⬇

Hypoglycemia

IV IM SC (Adults and Children >25 kg): 1 mg; may be repeated in 15 min if necessary.
SC (Adults and Children ≥12 yr): Gvoke: 1 mg; may be repeated in 15 min if necessary.
IV IM SC (Children <25 kg ): 0.5 mg or 0.02–0.03 mg/kg; may be repeated in 15 min if necessary.
IV IM SC (Children >6 yr and unknown weight): 1 mg; may be repeated in 15 min if necessary.
IV IM SC (Children <6 yr and unknown weight): 0.5 mg or 0.02–0.03 mg/kg; may be repeated in 15 min if necessary.
SC (Children 2–12 yr and ≥45 kg): Gvoke: 1 mg; may be repeated in 15 min if necessary.
SC (Children 2–12 yr and <45 kg): Gvoke: 0.5 mg; may be repeated in 15 min if necessary.
(Adults and Children ≥4 yr): 3 mg (one actuation) in one nostril; may be repeated in 15 min if necessary.

Radiographic Examination of the GI Tract

IM IV (Adults ): 0.25–2 mg; depending on location and duration of examination (0.5 mg IV or 2 mg IM for relaxation of stomach; for examination of the colon 2 mg IM 10 min before procedure).

Beta Blocker or Calcium Channel Blocker Overdose

IV (Adults ): Beta blocker overdose: 50–150 mcg (0.05–0.15 mg)/kg, followed by 1–5 mg/hr infusion. Calcium channel blocker overdose: 2 mg; additional doses determined by response.

Availability ⬆ ⬇

(Generic available)

Nasal powder: 3 mg/device
Lyophilized powder for injection: 1 mg/vial
Solution for SUBQ injection (Gvoke) (prefilled syringes and prefilled autoinjectors): 0.5 mg/0.1 mL; 1 mg/0.2 mL

Assessment ⬆ ⬇

Assess for signs of hypoglycemia (sweating, hunger, weakness, headache, dizziness, tremor, irritability, tachycardia, anxiety) prior to and periodically during therapy.
Assess neurologic status during therapy. Institute safety precautions to protect patient from injury caused by seizures, falling, or aspiration. For insulin shock therapy, 0.5–1 mg is administered after 1 hr of coma; patient usually awakens in 10–25 min. If no response occurs, repeat the dose. Feed patient supplemental carbohydrates orally to replenish liver glycogen and prevent secondary hypoglycemia as soon as possible after awakening, especially pediatric patients.
Assess nutritional status. Patients who lack liver glycogen stores (starvation, chronic hypoglycemia, adrenal insufficiency) will require glucose instead of glucagon.
Assess for nausea and vomiting after administration of dose. Protect patients with depressed level of consciousness from aspiration by positioning on side; ensure that a suction unit is available. Notify health care professional if vomiting occurs; patient will require parenteral glucose to prevent recurrent hypoglycemia.

Lab Test Considerations:

Monitor serum glucose levels throughout episode, during treatment, and for 3–4 hr after patient regains consciousness. Use of bedside fingerstick blood glucose determination methods is recommended for rapid results. Follow-up lab results may be ordered to validate fingerstick values, but do not delay treatment while awaiting lab results, as this could result in neurologic injury or death.
- Large doses of glucagon may cause a ↓ in serum potassium concentrations.

Implementation ⬆ ⬇

May be given SUBQ, IM, or IV.
- Administer supplemental carbohydrates IV or orally to facilitate increase of serum glucose levels.
SC: Gvoke solution is clear and colorless to pale yellow; do not administer if solution is discolored or contains particulate matter. Inject in lower abdomen, outer thigh, or outer upper arm.
Administer by inserting tip into one nostril and pressing device plunger all the way in until green line is no longer showing. Dose does not need to be inhaled. Call for emergency assistance immediately after administering dose. When patient responds to treatment, give oral carbohydrates.

IV Administration:

Reconstitution: Reconstitute each vial with 1 mL of an appropriate diluent. For doses 2 mg, use diluent provided by manufacturer. For doses >2 mg, use sterile water for injection instead of diluent supplied by manufacturer to minimize risk of thrombophlebitis, CNS toxicity, and myocardial depression from phenol preservative in diluent supplied by manufacturer. Reconstituted vials should be used immediately.Concentration: Not to exceed 1 mg/mL.
Rate: See Route/Dosage section.

Patient/Family Teaching ⬆ ⬇

Teach patient and family signs and symptoms of hypoglycemia. Instruct patient to take oral glucose as soon as symptoms of hypoglycemia occur; glucagon is reserved for episodes when patient is unable to swallow because of decreased level of consciousness.
Home Care Issues: Instruct family on correct technique to prepare, draw up, and administer injection. Health care professional must be contacted immediately after each dose for orders regarding further therapy or adjustment of insulin dose or diet.
Advise family that patient should receive oral glucose when alertness returns.
Instruct family to position patient on side until fully alert. Explain that glucagon may cause nausea and vomiting. Aspiration may occur if patient vomits while lying on back.
Instruct patient to check expiration date monthly and to replace outdated medication immediately.
Review hypoglycemic medication regimen, diet, and exercise programs.
Patients with diabetes mellitus should carry a source of sugar (such as a packet of sugar or candy) and identification describing disease process and treatment regimen at all times.
Rep: Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇