Response to nonprescription epinephrine inhaler during nocturnal asthma.
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).


CONCLUSIONS
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.
Hendeles
Leslie
L
College of Pharmacy and Department of Pediatrics, University of Florida, Gainesville, Florida 32610-0486, USA. hendeles@cop.ufl.edu
Marshik
Patricia L
PL
Ahrens
Richard
R
Kifle
Yemiserach
Y
Shuster
Jon
J
D000280:Administration, Inhalation; D000328:Adult; D001249:Asthma / Q000188:drug therapy*; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004837:Epinephrine / Q000008:administration & dosage / Q000627:therapeutic use; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D009330:Nebulizers and Vaporizers; D013997:Time Factors; D016896:Treatment Outcome
D001993:Bronchodilator Agents; D004837:Epinephrine