Effectiveness of bronchodilators in cystic fibrosis

Bronchodilators (xanthines, adrenergics, and parasympatholytics) have been used for years in the treatment of airway obstruction associated with cystic fibrosis. Their effectiveness in bringing about consistent and significant reversal of airway obstruction remains a topic for debate. A review of the literature suggests that the majority of patients with cystic fibrosis have hyperresponsive and hyperactive airways and will respond favorably to bronchodilators, at least some of the time. Bronchial hyperresponsiveness tends to be greater in patients with advanced disease than in mildly affected ones. Responses to bronchodilators appear to be greatest when airway disease is mild-to-moderate, when there is a documented excessive bronchial hyperresponsiveness to nonspecific bronchoconstrictors (methacholine, histamine), and when the patients are young. The response to intravenous xanthine and terbutaline is best when patients experience an acute pulmonary exacerbation and when aerosolized bronchodilators are relatively ineffective. Patients with advanced airway destruction and obstruction have a high degree of airway wall instability, which may be worsened by inhaled bronchodilators. Adrenergic and parasympatholytic aerosols are equally effective; combining them in optimal doses may be more beneficial than using either alone. Atropine and ipratropium bromide may be more effective in adults than children, but this remains to be further evaluated. Some of the apparently poor responses to inhaled bronchodilators are likely due to inadequate dosing. In conclusion, most patients with cystic fibrosis are likely to benefit from bronchodilator therapy when given in adequate doses, appropriate combinations, and by the appropriate route.