Efficacy of adding multiple doses of oxitropium bromide to salbutamol delivered by means of a metered-dose inhaler with a spacer device in adults with acute severe asthma

Abstract

Background: The efficacy of combination therapy adding multiple doses of anticholinergics to β2-agonists to improve outcome has not been established in adults with acute severe asthma. Objective: This study was undertaken to compare the outcome of adults with acute severe asthma treated with 4 puffs of salbutamol (100 μg/actuation) every 20 minutes for 3 doses plus 4 puffs of oxitropium bromide (100 μg/actuation) with each of the 3 salbutamol doses versus salbutamol alone administered by means of a metered-dose inhaler with a spacer device. Methods: A randomized, single-blind, placebo-controlled study was performed in 74 patients between 18 and 55 years old presenting to the emergency department (ED) for treatment of acute asthma with a peak expiratory flow (PEF) of 50% or less than the normal predicted value. The primary endpoint was improvement in PEF over the course. The secondary endpoint was the need for additional ED treatment at 120 minutes. Results: The increase in PEF over the course was significantly greater in the oxitropium plus salbutamol treatment group (P < .0001). The mean absolute difference in PEF at 120 minutes for combination therapy compared with salbutamol alone was 37.8 L/min (P = .001). In addition, the proportion of need for additional ED treatment was less in the combination group than the group receiving salbutamol alone (odds ratio, 0.32; 95% confidence interval, 0.11-0.90). Conclusion: Adding multiple doses of oxitropium bromide to salbutamol delivered by means of a metered-dose inhaler with a spacer device for acute severe asthma produces a significant improvement in lung function and reduces the need for additional ED treatment. (J Allergy Clin Immunol 2000;106:472-8.)