epinephrine
Brand: Adrenalin, EpiPen
ISMP High Alert Prototype Drug
Drug Class: vasopressor / bronchodilator
Drug Family: vasopressor
Subclass: endogenous catecholamine
Organ Systems: cardiovascularrespiratorypns-autonomic
Mechanism of Action
Non-selective alpha and beta agonist; in cardiac arrest: alpha-1 increases coronary/cerebral perfusion; beta-1 increases HR and inotropy; beta-2 causes bronchodilation; alpha-1 also mediates anaphylaxis reversal.
alpha-1alpha-2beta-1beta-2 adrenergic receptors
Indications
- cardiac arrest (ACLS — 1 mg IV q3-5 min)
- anaphylaxis (IM — first line)
- severe bronchospasm/asthma (severe)
- croup (nebulized)
- local anesthesia adjunct (vasoconstriction)
Contraindications
- hypertension (pheochromocytoma)
- angle-closure glaucoma (ophthalmic)
- cocainerabuse (relative)
Adverse Effects
Common
- tachycardia
- anxiety
- palpitations
- hypertension
- tremor
Serious
- severe arrhythmias
- hypertensive crisis
- pulmonary edema
Pharmacokinetics (ADME)
| Absorption | poor oral (destroyed in gut); IM/SC/IV |
| Distribution | wide |
| Metabolism | MAO and COMT (liver and tissues) |
| Excretion | renal metabolites |
| Half-life | 1-2 minutes |
| Onset | immediate |
| Peak | immediate |
| Duration | 15-30 min |
| Protein Binding | <0% |
| Vd | variable |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| non-selective beta-blockers | paradoxical severe hypertension (unopposed alpha) with epinephrine — potential crisis | major |
| MAOIs | prolonged, exaggerated pressor response | major |
| cocaine | severe hypertension and cardiac ischemia | major |
Nursing Considerations
- Anaphylaxis: IM injection in outer mid-thigh (vastus lateralis) — NOT gluteal (unreliable absorption)
- ACLS: 1 mg IV/IO every 3-5 minutes during CPR
- Auto-injector (EpiPen): teach patient to hold pen in place 10 seconds after injection
- Keep patient recumbent after IM injection
- Second EpiPen dose if needed after 5-15 minutes
Clinical Pearls
- IM preferred over SC in anaphylaxis: faster, more reliable absorption
- Anaphylaxis reversal: alpha-1 reverses vasodilation, beta-2 bronchodilates, alpha-1 reduces mucosal edema
- Auto-injector threshold: ≥30 kg → 0.3 mg adult; 15-30 kg → 0.15 mg junior
Safety Profile
Pregnancy use-with-caution
Lactation use-with-caution
Renal Adjustment Not required
Hepatic Adjustment Not required
TDM Not required
Concordance Terms
Cross-referenced clinical concepts — click any term to see all content where it appears.