Randomized, single blind, controlled trial of inhaled glutathione vs placebo in patients with cystic fibrosis.

Background: In cystic fibrosis (CF) the defective CF transmembrane conductance regulator protein may be responsible for the impaired transport of glutathione (GSH), the first line defense of the lung against oxidative stress. The aim of this single-blind, randomized, placebo-controlled trial was to evaluate the effect of inhaled GSH in patients with CF. Methods: 54 adult and 51 pediatric patients were randomized to receive inhaled GSH or placebo twice daily for 12 months. Results: Twelve month treatment with inhaled GSH did not achieve our predetermined primary outcome measure of 15% improvement in FEV1%. Only in patients with moderate lung disease, 3, 6 and 9 months therapy with GSH resulted in a statistically significant increase of FEV1 values from the baseline. Moreover GSH therapy improved 6-minute walking test in pediatric population. GSH was well tolerated by all patients. Conclusions: Inhaled GSH has slight positive effects in CF patients with moderate lung disease warranting further study.