α/β agonist
Epinephrine
Adrenalin Vasopressor — violet 1 mg/mL (IM)0.1 mg/mL (code syringe)⚠ 10 mcg/mL push-dose (locally prepared)
First-line for anaphylaxis and cardiac arrest; a potent inotrope and vasopressor.
Typical adult doses
| Indication | Dose | Onset | Duration |
|---|---|---|---|
| Anaphylaxis (IM) | 0.5 mg IM (1 mg/mL), anterolateral thigh | — | — |
| Anaphylaxis under anesthesia | Titrated IV boluses per protocol (AAGBI 2021: 50 mcg) | — | — |
| Cardiac arrest | 1 mg IV/IO every 3–5 min | — | — |
| Infusion | ≈0.01–0.1 mcg/kg/min, titrated | — | — |
Mechanism
α1, β1 and β2 agonist.
Key effects
- α1: vasoconstriction ↑BP
- β1: ↑HR and contractility
- β2: bronchodilation; mast-cell stabilization
Watch out for
- Arrhythmias, hypertension
- Concentration errors (1 mg/mL vs 0.1 mg/mL vs 10 mcg/mL) are a classic catastrophe
Pimp questions
Pimp question
Why epinephrine in anaphylaxis?
Answer
α1 restores BP, β1 supports contractility, β2 bronchodilates and stabilizes mast cells (↑cAMP), limiting further mediator release.