[Role of anticholinergic agents in the treatment of cystic fibrosis].

A significant proportion of patients with cystic fibrosis (CF) demonstrate increased airways hyperreactivity, a feature that has been well documented by several authors. This bronchial lability is more pronounced in those with more severe and advanced lung disease. Several mechanisms for this increased airways responsiveness have been proposed such as chronic inflammation with impairment of mucosal permeability, increase in amount of bronchial secretions, systemic autonomic abnormality, increase in incidence of atopy and airway narrowing and changes in airway geometry induced by chronic inflammation. Several studies have assessed the change in FEV1 after beta-agonist or anticholinergic therapy in CF patients and there are studies in which the effect of the combination of drugs was tested. In a group of young CF patients, we found on average a 7% increase in FEV1 after salbutamol and a 10% improvement after ipratropium bromide (IB). After inhaling both drugs, there was a 17% increase in FEV1 from baseline. There were also significant changes in static volumes and airway-resistance measurements when salbutamol and IB were administered in combination. The influence of pretreatment of either normal saline, salbutamol or ipratropium bromide with methacholine was evaluated by Avital and co-workers in a double-blind crossover study. They found an increase in PC20 without a change in baseline FEV1 following salbutamol and an even greater change after IB. These results suggest that the adrenergic agent altered the smooth muscle contractile mechanism, and that muscarinic pathway appears to be important in the pathogenesis of expiratory airflow obstruction in some CF patients. The mechanisms of this cholinergic sensitivity are unclear.(ABSTRACT TRUNCATED AT 250 WORDS)