The aim of this study was to evaluate the bronchodilating capacity of nebulized oxitropium bromide (OB) in preschool asthmatic children and to determine an appropriate dose for usage in this age group. The trial enrolled 20 patients with moderate to severe stable asthma aged between 3.2 and 6.2 years (mean 4.7). Applying a placebo controlled, double-blind design, the effect of placebo was compared with three different doses of OB (375, 750 and 1500 micrograms) and with 400 micrograms fenoterol. The three different doses of OB resulted in a highly significant bronchodilation within 15 min after administration. The observed bronchodilation was comparable between the three doses during the first 2 h. However, after 4 h the lowest dose was significantly less powerful than the highest dose. Compared to the additional bronchodilation induced by fenoterol, no difference was found with the degree of bronchodilation of OB which occurred during the first 2 h. Furthermore, after 4 h only the lowest dose of OB was significantly less powerful than fenoterol assessed 10 min following a single 400 micrograms dose.
Conclusion: Oxitropium bromide is a potent and long-acting bronchodilator in preschool children at a dose of 750 micrograms and 1500 micrograms. No side-effects were observed. The exact duration of action remains uncertain, but even 4 h after inhaling 750 or 1500 micrograms of OB no additive bronchodilation induced by fenoterol could be observed.