Effect of inhaled beclomethasone dipropionate on bronchial hyperreactivity in asthmatic children during maximal allergen exposure

In this double blind study we evaluated the effect of a 2 months long treatment with inhaled beclomethasone dipropionate (300 micrograms/day) on methacholine responses in asthmatic children, during a period of maximal allergen exposure. Baseline values of methacholine PC20-FEV1 were 0.66 +/- 0.22 mg/mL (mean +/- SEM) in 10 children treated with the active drug and 0.78 +/- 0.21 mg/mL in 10 children treated with placebo. After 1 month of treatment PC20-FEV1 was 1.91 +/- 0.64 and 0.80 +/- 0.33 mg/mL, respectively, in the groups treated with beclomethasone versus placebo. A statistically significant reduction in bronchial hyperreactivity (PC20-FEV1, 5.49 +/- 1.86 mg/mL) but no systemic side effects were observed after 2 months of treatment with beclomethasone dipropionate. This is compared with a PC20-FEV1 of 1.38 +/- 0.52 mg/mL in the placebo group. The results confirm the effect of inhaled corticosteroids in reducing bronchial hyperreactivity, even during a period of maximal allergen exposure.