Epinephrine
Adrenalin
Endogenous catecholamine, α + β agonist
α1 (vasoconstriction), α2, β1 (inotropy + chronotropy), β2 (bronchodilation, vasodilation in skeletal muscle). Dose-dependent receptor preference: low-dose β-predominant, high-dose α-predominant.
Indications
- •Anaphylaxis
- •Cardiac arrest
- •Hemodynamic support / inotropy
- •Bronchospasm
- •Local anesthetic vasoconstrictor
Dosing
| Context | Adult | Pediatric |
|---|---|---|
| Anaphylaxis IM | 0.3–0.5 mg IM (1:1000) | 0.01 mg/kg IM |
| Anaphylaxis IV titrated | 10–100 mcg IV q1–2 min | — |
| Cardiac arrest | 1 mg IV q3–5 min | 0.01 mg/kg IV q3–5 min |
| Inotrope infusion | 0.02–0.5 mcg/kg/min | — |
| Local anesthetic adjunct | 1:200,000 (5 mcg/mL) — max 4.5 mg/kg lido + epi | — |
Pharmacokinetics
Onset seconds. Duration 5–10 min. Catecholamine reuptake + COMT/MAO degradation.
Hemodynamic effects
↑HR, ↑contractility, ↑CO. SVR ↑ at high dose, ↓ at low dose (β2). Can paradoxically ↓BP at very low doses.
Respiratory effects
Bronchodilation. Decongestant (mucosal vasoconstriction).
Side effects
- !Tachyarrhythmias
- !Hyperglycemia
- !Lactic acidosis
- !Tissue ischemia at extravasation site (treat with phentolamine local infiltration)
- !Pulmonary edema (high-dose, prolonged)
Contraindications
- ×None for life-threatening indications
Clinical pearls
- ★Anaphylaxis: IM lateral thigh fastest absorption; IV in resuscitation only.
- ★LAST: drop epi to ≤1 mcg/kg (≤100 mcg).
- ★Caution: with halothane ('sensitized myocardium' — but halothane is rarely used in 2026).
Education only — confirm against current package inserts and institutional protocols. Doses assume normal organ function unless otherwise noted.