Acetylcysteine has been suggested as a beneficial treatment for idiopathic pulmonary fibrosis, although data from placebo-controlled studies are lacking.
In the initial double-blind, placebo-controlled trial, researchers have randomly assigned patients who had idiopathic pulmonary fibrosis with mild-to-moderate impairment in pulmonary function to receive a three-drug regimen of Prednisone, Azathioprine, and Acetylcysteine; Acetylcysteine alone; or placebo.
The study was interrupted owing to safety concerns associated with the three-drug regimen. The trial continued as a two-group study ( Acetylcysteine vs placebo ) without other changes; 133 and 131 patients were enrolled in the Acetylcysteine and placebo groups, respectively.
The primary outcome was the change in forced vital capacity ( FVC ) over a 60-week period.
At 60 weeks, there was no significant difference in the change in forced vital capacity between the Acetylcysteine group and the placebo group ( -0.18 liters and -0.19 liters, respectively; P=0.77 ).
In addition, there were no significant differences between the Acetylcysteine group and the placebo group in the rates of death ( 4.9% vs. 2.5%, P=0.30 by the log-rank test ) or acute exacerbation ( 2.3% in each group, P greater than 0.99 ).
As compared with placebo, Acetylcysteine offered no significant benefit with respect to the preservation of forced vital capacity in patients with idiopathic pulmonary fibrosis with mild-to-moderate impairment in lung function. ( Xagena )
The Idiopathic Pulmonary Fibrosis Clinical Research Network, N Engl J Med 2014; 370:2093-2101