Objective: We hypothesized that children with moderate acute asthma exacerbations receiving oral montelukast with standard therapy will have at least 12% greater forced expiratory volume in 1 second (FEV1) improvement in 3 hours than those receiving standard therapy alone.
Methods: In this randomized, double-blind, placebo-controlled study, we enrolled emergency patients aged 6 to 14 years with moderate acute asthma exacerbations (peak expiratory flow rate, 40%-70% predicted). Subjects received montelukast 5 mg or placebo orally then standard therapy. We measured FEV1 before study medication administration and hourly for 3 hours. The primary outcome was FEV1% predicted change at 3 hours.
Results: At the time of the planned interim analysis, we had enrolled 27 subjects; 23 (11 montelukast, 12 placebo) had a complete FEV1 data. Both groups had similar mean FEV1 increases at 3 hours (mean [SD]: montelukast = 16.8% [11.4%], placebo = 19.9% [12.1%]; 95% confidence interval for difference = -12.22% to 5.95%). Based on further analysis, we determined that enrollment of the planned sample was unlikely to significantly change the results. If our study hypothesis were true, the montelukast group mean FEV1 increase should be 32% or greater. The probabilities were low that the montelukast sample could be drawn from a normally distributed population with a mean of 32% and that subsequently enrolled montelukast subjects would have sufficient FEV1 improvements to attain a mean of greater than 32%.
Conclusion: Based on these results, for children aged 6 to 14 years with moderate acute asthma exacerbations, oral montelukast (5 mg) added to standard therapy as in this design is unlikely to result in additional FEV1 improvements in 3 hours.