Background: Many health care professionals believe that a nonprescription epinephrine metered-dose inhaler is less effective and shorter acting and has more cardiovascular adverse effects than prescription beta2-agonists.
Objective: To determine if increasing the epinephrine dose improves efficacy safely.
Methods: Eight patients with nocturnal asthma (age range, 20-46 years) were treated in a randomized, crossover manner on 2 different nights while sleeping in a clinical research center. On awakening from asthma symptoms, 2, 4, and 8 actuations of epinephrine or albuterol were administered at 17-minute intervals (14 cumulative actuations). Forced expiratory volume in 1 second (FEV1), asthma symptoms, and systemic effects were measured before the first dose, during the 9- to 17-minute period after each dose, and 30 minutes after the last dose.
Results: The mean +/- SD FEV1 at the onset of symptoms was 45% +/- 11% and 44% +/- 12% predicted before epinephrine and albuterol, respectively, and increased to a maximum of 86% +/- 11% and 93% +/- 10%, respectively (P = .04). Symptoms decreased as FEV1 improved and did not return after either treatment; 6 patients were symptom free after 14 cumulative actuations of epinephrine compared with 6 cumulative actuations of albuterol. Heart rate decreased to 71 +/- 10/min after epinephrine but increased to 92 +/- 14/min after albuterol (P = .001). After the last dose, serum potassium concentration was 3.6 +/- 0.3 micromol/L after epinephrine and 3.2 +/- 0.4 micromol/L after albuterol (P = .01).
Conclusion: Epinephrine was nearly as effective as albuterol in terminating an acute episode of airway obstruction but without cardiovascular effects in these otherwise healthy young adults.