Inhaled ipratropium bromide and terbutaline in asthmatic children

Inhaled bronchodilator therapy in young asthmatic children reduces symptoms and improves lung function. After a single dose of therapy, however, lung function may still be abnormal, as evidenced by an elevated function residual capacity (FRC). The aims of this study were to assess if a second dose of bronchodilator therapy resulted in further improvement in lung function and to determine whether additional therapy was more effective if given as a second dose of a beta-adrenergic agonist or if instead an anticholinergic was used. Twenty-one asthmatics (median age 7.5 years) received in random order on two separate occasions, 1 week apart, either two doses of terbutaline (500 micrograms) or terbutaline plus ipratropium bromide (20 micrograms). FRC and peak expiratory flow rate (PEFR) were measured immediately prior to and then 20 min after each dose of bronchodilator therapy. In the group, overall FRC and PEFR improved after the first and second dose of bronchodilator, regardless of regime used, the response to the second dose, however, was smaller than the first dose. There was no significant difference overall between the two regimes in baseline FRC or PEFR, or FRC and PEFR measured after each dose of bronchodilator. Eight children failed to show a significant change in FRC following two doses of terbutaline, but seven of these eight did have a significant change in FRC in response to the combination of terbutaline and ipratropium bromide. We conclude that a second dose of bronchodilator therapy does further improve lung function. Our results suggest the more efficacious regime consists of a combination of single doses of ipratropium bromide and terbutaline.