50:50 mix of D- and L-epinephrine (only the L-isomer is active). Alpha-1 vasoconstriction shrinks swollen subglottic and laryngeal mucosa; beta-2 effects add mild bronchodilation.
Dosing
Adult
0.5 mL of 2.25% solution in 3 mL normal saline by nebulizer
Pediatric
0.05 mL/kg of 2.25% solution (max 0.5 mL) diluted to 3 mL, by nebulizer
L-epinephrine 1 mg/mL (1:1000), 0.5 mL/kg up to 5 mL nebulized, is an equivalent alternative.
Indications
Moderate-to-severe croup (stridor at rest)
Post-extubation stridor and laryngeal edema
Contraindications
Hypertrophic obstructive cardiomyopathy or tetralogy of Fallot (relative)
Use with caution in significant tachyarrhythmia
Side effects
Tachycardia
Tremor, pallor
Hypertension
Rebound of stridor as the effect wears off
Monitoring parameters
Stridor, work of breathing and SpO2
Heart rate
Observe for rebound for at least 2–4 hours after the last dose