Study objective: To determine the efficacy of intravenous aminophylline in the treatment of adult patients hospitalized for exacerbation of asthma.
Design: Randomized, double-blind, placebo-controlled trial throughout the study.
Setting: University Hospital Clinical Research Center.
Patients: Forty-four patients admitted from the emergency room with a primary diagnosis asthma; 39 patients completed the study.
Interventions: Patients received either intravenous aminophylline or placebo in addition to frequent nebulized albuterol; prednisone 0.5 mg/kg body weight every 6 h orally; and supplemental oxygen. Aminophylline infusion rates were adjusted to achieve serum theophylline concentrations of 10 to 20 micrograms/ml. Changes were made in placebo infusion rates to maintain the double blind design.
Measurements and results: Forced expiratory volume in 1 s (FEV1) and other spirometric measurements every 8 h by a blinded investigator or trained respiratory therapist. Subjective patient response and duration of hospitalization were compared. No difference in spirometric measurements was observed between the two groups at any time point. On admission to the study, FEV1 in the placebo group was 41.5 (+/- 2.9) percent predicted and in the aminophylline group 34.7 (+/- 2.3) percent predicted (p = 0.08). At discharge, FEV1 was 70.4 (+/- 2.9) percent predicted in the placebo group and 63.7 (+/- 2.8) percent predicted in the theophylline group (p = 0.10). There was no difference in subjective patient rating or duration of hospitalization between the two groups (placebo 1.95 days and aminophylline 1.78 days, p = 0.51).
Conclusions: Our results suggest that aminophylline therapy does not add significant benefit to other standard therapies in hospitalized adult asthmatic patients. Because of the risks and cost of aminophylline treatment in the hospital setting, further research is needed to determine if there are subgroups of adult asthmatics who may benefit from the addition of aminophylline to other standard optimal therapies.