Long-term effect of ipratropium bromide and fenoterol on the bronchial hyperresponsiveness to histamine in children with asthma.

We studied the effects of the anticholinergic ipratropium bromide (40 micrograms three times daily) and the beta-agonist, fenoterol (0.2 mg three times daily), both administered by powder inhaler, on bronchial hyperresponsiveness (BHR) to histamine in children, aged 7 to 15 years with mild stable asthma and limited bronchoconstriction who had a highly increased BHR. The double-blind, randomized, parallel study was conducted and performed in spring and early summer. BHR and FEV1 were measured on two occasions, before the start of treatment and monthly thereafter for 4 months. Symptoms, peak expiratory flow, and concomitant medication were registered daily. Nine of the 12 patients receiving ipratropium bromide and all eight patients receiving fenoterol completed the study. Patients completing treatment had few symptoms and were in a stable condition throughout the treatment period. Neither the administration of ipratropium bromide nor fenoterol resulted in a significant change of BHR. We concluded that long-term treatment with ipratropium bromide or fenoterol had no effect on BHR in children with mild stable asthma.