Efficacy and safety of inhaled N-acetylcysteine in idiopathic pulmonary fibrosis: A prospective, single-arm study

Respir Investig. 2016 May;54(3):156-61. doi: 10.1016/j.resinv.2015.10.001. Epub 2015 Dec 15.


Background: Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with few treatment options. The efficacy of N-acetylcysteine in patients with IPF remains controversial. The aim of this research was to investigate the efficacy of inhaled N-acetylcysteine.

Methods: This study was designed as a single-center, single-arm, prospective clinical trial. Each patient who had IPF received 352.4mg of inhaled N-acetylcysteine twice daily.

Results: In total, 28 patients were enrolled. The mean values of the respiratory function parameters at the initiation of therapy were as follows: forced vital capacity (FVC), 2.27L and %FVC, 76.2%. The mean change in FVC during 26 weeks prior to the inhaled N-acetylcysteine therapy was -170mL, a significant decrease (p=0.019). The mean change in FVC during 26 weeks after the initiation of inhaled N-acetylcysteine therapy was -70mL (p=0.06). When the patients were classified into two groups according to the degree of decline in FVC (≥100mL vs. <100mL) during the 26-week period prior to the initiation of therapy, inhaled N-acetylcysteine showed a greater efficacy in attenuating FVC decline in the ≥100-mL group than in the <100-mL group.

Conclusions: Inhaled N-acetylcysteine therapy was effective in patients with mild-to-moderate IPF and was more beneficial in patients who had greater declines in FVC before the initiation of therapy. (UMIN title: Efficacy and safety of inhaled N-acetylcysteine in idiopathic pulmonary fibrosis, UMIN000016706, 2015/03/04.).

Keywords: Forced vital capacity; Idiopathic pulmonary fibrosis; Inhalation; Krebs von den Lungen-6; N-acetylcysteine.

Publication types

  • Clinical Trial

MeSH terms

  • Acetylcysteine / administration & dosage*
  • Administration, Inhalation
  • Aged
  • Female
  • Humans
  • Idiopathic Pulmonary Fibrosis / drug therapy*
  • Idiopathic Pulmonary Fibrosis / physiopathology*
  • Male
  • Respiratory Function Tests
  • Severity of Illness Index
  • Time Factors
  • Treatment Outcome
  • Vital Capacity*


  • Acetylcysteine