Proventil HFA Prevents Exercise-Induced Bronchoconstriction in Children

Short-acting inhaled beta₂-agonists used just prior to exercise are an effective method for preventing exercise-induced bronchoconstriction (EIB) in children. This was a randomized, single-blind, placebo-controlled, four-period crossover study that compared the effectiveness of albuterol formulated in hydrofluoro-alkane-134a (HFA) to albuterol formulated in chlorofluorocarbons (CFCs) and to placebo in protecting asthmatic children age 6-11 from EIB. Patients self-administered either HFA albuterol, two different CFC albuterol products, or placebo 30 min prior to exercise challenge. Spirometry was performed predose and 5, 10, 15, 30, 45, 60, 75, and 90 min after the exercise challenge was completed. The smallest percent change from the predose forced expiratory volume in 1 sec (FEV₁) after exercise challenge was similar for the three active treatments, and each of the active treatments was significantly better than placebo. Each active treatment had significantly fewer patients unprotected from EIB (unprotected defined as having ≥20% fall in FEV, after exercise challenge) than placebo. Changes in heart rate, blood pressure and electrocardiogram