Effect of different inhaled bronchodilators on recovery from methacholine-induced bronchoconstriction in asthmatic children

Two hundred fourteen children with mild to moderate asthma were studied to determine bronchodilator effects 5 min after administration of five differe nt metered dose inhaler (MDI) aerosol formulations available in our country , and results were compared to placebo. Methacholine bronchial challenge wa s performed by the tidal breathing method, using increasing concentrations until a fall in forced expired volume in 1 s (FEV1) greater than or equal t o 20% was achieved (PC20). Immediately after FEV1 had fallen 20% or more, c hildren were randomly allocated into 1 of 6 groups to receive: salbutamol 2 00 mu g (S), fenoterol 200 mu g (F), salbutamol 200 mu g + beclomethasone 1 00 mu g (S + B), fenoterol 200 mu g + ipratropium bromide 80 mu g (F + IB), salmeterol 50 mu g (SM), and placebo (P). The bronchodilator effect was de termined by measuring FEV1 5 min after inhalation of medications. Nonparame tric tests were used for statistical analysis. The six groups were similar in anthropometric and in respiratory characteri stics. All five inhaled aerosols containing beta-agonists caused a signific ant bronchodilator effect as compared to placebo. However, the effect was s ignificantly greater in the groups treated with F or F + IB (P < 0.05) comp ared to other formulations. We conclude that the five types of aerosols used in this study are able to reverse methacholine-induced bronchoconstriction 5 min after inhalation of a bronchodilator. Pediatr Pulmonol, 1999; 28:125-129. (C) 1999 Wiley-Liss, Inc.