Purpose: The optimal dose of albuterol to use in the
treatment of acute asthma has yet to be established. The National
Asthma Education and Prevention Program (NAEPP) recommends a starting
dose of 2.5 to 5 mg of aerosolized albuterol every 20 min, although
European authorities recommend higher doses. The purpose of this study
was to compare 2.5 vs 7.5 mg of nebulized albuterol for the treatment
of acute asthma.
Subjects: We studied 160 patients
presenting to the emergency department with acute asthma.
Methods: On enrollment, patients underwent baseline
testing, including initial spirometry. All patients received
prednisone, 60 mg, orally. Patients then received in a randomized,
double-blinded fashion, nebulized albuterol either 2.5 or 7.5 mg every
20 min for a total of three doses. Spirometry was repeated after each
of the first two treatments and again 40 min after completion of the
Results: The pretreatment
FEV1 was 36.9 ± 16.6% of predicted normal in the
low-dose group vs 41.5 ± 15.4% of predicted normal in the high-dose
group (not significant [NS]). The patients in the low-dose group had
a 50.3 ± 62.6% improvement in FEV1 pretreatment to
post-treatment, whereas those in the high-dose group had a
44.6 ± 48.2% improvement in FEV1 (NS). There was no
difference in the admission rate in the low-dose group (43%) as
compared with that of the high-dose group (39%; NS).
Conclusion: We conclude that there is no advantage to the
routine administration of doses of albuterol higher than 2.5 mg every
20 min. It is possible that there may be an advantage in the most
severely obstructed patients, although this study did not enroll enough
patients with very severe asthma to evaluate this. As has been
previously demonstrated, patients who subsequently require admission
have a diminished response to albuterol. This decreased responsiveness
is seen with the first aerosol administration and is unaffected by
increasing the dose.