INFLUENCE OF BUDESONIDE ON THE RESPONSE TO INHALED TERBUTALINE IN CHILDREN WITH MILD ASTHMA

The aim of this study was to evaluate if continuous treatment with bud esonide or salmeterol influences the bronchodilator response to terbut aline in children with asthma; 23 children, aged 7 to 16 years (mean = 11 years), with mild asthma were treated with inhaled budesonide 100 mu g b.i.d; and placebo for three weeks in a randomized, double blind crossover study. These treatments were followed by treatment with inha led salmeterol 50 mu g b.i.d. for 3 weeks. On the last day of each per iod a cumulative dose-response experiment with terbutaline in the dose s 50, 100, 250 and 500 mu g (cumulative dose 900 mu g) was performed. Lung function was measured before and 20 min after each terbutaline in halation. Baseline pulmonary functions after budesonide treatment were significantly higher than the baseline measured after the two other t reatments (p<0.05). After budesonide treatment, the dose-response curv e was shifted vertically upwards but otherwise parallel to the dose-re sponse curve after placebo. The increase from baseline after the first cumulative dose of terbutaline was significantly lower after salmeter ol treatment than after the two other treatments (p<0.01). Maximal lun g functions after 900 mu g terbutaline also differed significantly bet ween the three dose-response days; budesonide being significantly high er and salmeterol significantly lower than placebo (p=0.02 and p<0.001 , respectively). It is concluded that budesonide treatment does not en hance the brochodilator response to terbutaline. Further studies are n eeded to assess if long-term continuous salmeterol treatment reduces t he response to terbutaline.