Assessment of bronchospasm in patients with cystic fibrosis.

A controlled investigation of the response of 61 patients with cystic fibrosis to an aerosol of isoproterenol or epinephrine revealed a significant response to both drugs. From this it was concluded that bronchospasm contributes to the airway obstruction in this disease, although the obstruction is primarily caused by the accumulation of abnormal bronchial secretions. These findings have relevant therapeutic implications.