Adrenaline (Epinephrine)

Drug class

Sympathomimetic

Pharmacology

Agonist at α- and β-adrenergic receptors → ↑HR and contractility (β1), bronchodilation (β2), peripheral vasoconstriction (α1), increased ventricular irritability.

Metabolism

Metabolised by sympathetic nerve endings and broken down by monoamine oxidase (MAO) at synapses.

Indications

Cardiac arrest, anaphylaxis, severe life-threatening bronchospasm, shock unresponsive to fluids, bradycardia with poor perfusion, croup.

Precautions

Hypertension, hypovolaemic shock, MAOI therapy, quetiapine toxicity

Side effects

Anxiety, hypertension, palpitations/tachyarrhythmias, pupil dilation, tremor

Presentation (common pre-hospital forms)

Ampoules: 1 mg/1 mL (1:1,000) and 1 mg/10 mL (1:10,000) EpiPen 300 mcg

Onset

IV=30 seconds IM=60 seconds

Duration

5-10 minutes

Half-Life

2 minutes

Schedule

S3 (therapeutic poison)

Routes of administration

NEB, IM, IV, IO, IO

Adult doses Anaphylaxis: IM

500 mcg rep 5 mins no max

Adult doses Anaphylaxis: EpiPen

300 mcg single dose

Adult doses Anaphylaxis NED

5 mg single dose

Adult doses Severe life-threatening bronchospasm IM

500 mcg rep 5 min no max

Adult doses Cardiac arrest IV/IO

1 mg rep 3-5 min no max

Adult doses Shock / refractory anaphylaxis: IV/IO bolus

20-50 mcg then commence infusion at 10 mcg/min (10 mL/hr with stated mix), titrate; max infusion 50 mcg/min.