Epinephrine

Key Points

• Epinephrine (adrenaline) is a potent alpha- and beta-adrenergic receptor agonist (catecholamine).
• First-line treatment for anaphylaxis and a key agent in cardiac resuscitation (ACLS).
• Produces bronchodilation, increased heart rate and contractility, and peripheral vasoconstriction.
• EpiPen (auto-injector) effects fade after 15 to 20 minutes; seek emergency medical care immediately after use.

Mechanism of Action

Epinephrine stimulates both alpha- and beta-adrenergic receptors. Alpha-1 stimulation causes peripheral vasoconstriction, raising blood pressure. Beta-1 stimulation increases heart rate and myocardial contractility. Beta-2 stimulation causes bronchodilation and relaxation of smooth muscle. These combined effects support circulation and airway patency in emergency situations.

Indications

• Severe allergic reactions (anaphylaxis) — first-line treatment.
• Acute bronchospasm during severe asthma attacks.
• Cardiac resuscitation (ACLS protocol).
• Severe hypotension in shock states.
• Local injection to control superficial bleeding (vasoconstrictor effect).

Nursing Considerations

• Monitor heart rate, blood pressure, and cardiac rhythm continuously during IV administration.
• Assess for extravasation at IV site; epinephrine can cause tissue necrosis.
• Check EpiPen expiration date; store at room temperature and protect from light.
• Effects of intramuscular injection (EpiPen) fade after 15 to 20 minutes; ensure emergency medical follow-up.
• Use with caution in clients with cardiac arrhythmias, coronary artery disease, or hyperthyroidism.

Side Effects and Adverse Effects

• Common: Hypertension, tachycardia, palpitations, anxiety, tremor, headache.
• Serious: Cardiac arrhythmias, myocardial ischemia, hypertensive crisis.
• Local: Tissue necrosis from extravasation or repeated local injection.

Health Teaching

• Clients with anaphylaxis risk should carry an EpiPen at all times.
• Administer EpiPen into the outer thigh; can inject through clothing in emergencies.
• Seek immediate emergency medical care after EpiPen use because effects are temporary.
• Replace EpiPen before expiration date; check clarity of solution regularly.

Related Concepts

• anaphylaxis - Primary emergency indication for epinephrine.
• atropine - Co-administered in cardiac emergency contexts (ACLS).
• beta-blockers - Pharmacologic antagonist relationship.

Self-Check

1. Why is epinephrine the first-line drug for anaphylaxis?
2. What monitoring is essential during IV epinephrine administration?
3. Why must clients seek emergency care after using an EpiPen even if symptoms improve?