NO ADDED BENEFIT FROM NEBULIZED AMILORIDE IN PATIENTS WITH CYSTIC-FIBROSIS

In cystic fibrosis (CF) airway epithelial sodium absorption is increas ed 2-3 fold. Since sodium absorption is inhibited by the sodium channe l blocker amiloride, our aim was to assess its therapeutic benefit in cystic fibrosis. A randomized, double-blind, placebo-controlled, cross -over trial of nebulized amiloride was performed in 23 patients with c ystic fibrosis. Amiloride or placebo was administered four times daily for two six month periods. Existing treatment was continued, and any infective exacerbations treated in the usual way. Fourteen patients co mpleted the study. No significant changes occurred in forced expirator y volume in one second, forced vital capacity, oxygen saturation, body weight, sputum volume, culture and rheology, serum urea, and electrol ytes, white cell count and erythrocyte sedimentation rate during eithe r treatment period. The frequency of infective exacerbations was also not different in either treatment period. We were thus unable to confi rm the benefit shown in the only other clinical trial of nebulized ami loride in cystic fibrosis and conclude that, in the presence of establ ished treatment for cystic fibrosis lung disease, nebulized amiloride offers no additional clinical benefit.