A Pilot Study of Aerosolized Amiloride for the Treatment of Lung Disease in Cystic Fibrosis

Excessive active absorption of sodium is a unique abnormality of the airway epithelium in patients with cystic fibrosis. This defect is associated with thickened mucus and poor clearance of airway secretions and may contribute to the pulmonary disease in these patients. To study whether the inhibition of excessive absorption of sodium might affect the course of lung disease in cystic fibrosis, we performed a double-blind, crossover trial comparing aerosolized amiloride (5 mmol per liter; 3.5 ml four times daily), a sodium-channel blocker, with vehicle alone. Fourteen of the 18 adult patients initially enrolled in the study completed the one-year trial (25 weeks for each treatment). The mean (±SEM) loss of forced vital capacity (FVC) was reduced from 3.39±1.13 ml per day during treatment with vehicle alone to 1.44±0.67 ml per day during treatment with amiloride (P