Efficacy of N-acetylcysteine plus pirfenidone in the treatment of idiopathic pulmonary fibrosis：a systematic review and meta-analysis

Background: Numerous studies have demonstrated the potential of pirfenidone to enhance the prognosis of patients afflicted with idiopathic pulmonary fibrosis (IPF). Although N-acetylcysteine (NAC) is utilized as an antioxidant in IPF treatment, the combination of NAC and pirfenidone has produced inconsistent outcomes in certain studies. To assess the clinical effectiveness and safety of NAC plus pirfenidone (designated as the treatment group) versus pirfenidone monotherapy (designated as the control group), we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs). Methods RCTs of NAC plus pirfenidone were reviewed searching from databases and networks of unpublished and published studies in any language. Using pair-wise meta-analysis, changes in pulmonary function test (PFT) parameters and safety were evaluated . Results Two independent reviewers selected and obtained data from 5 RCTs (n = 398), comprising 1 study from Japan, 1 from Europe, and 3 from China. Based on changes in forced vital capacity (ΔFVC), changes in forced vital capacity percent predicted (ΔFVC%), changes in 6-minute walking test distance (Δ6MWT), and changes in percentage of predicted carbon monoxide diffusing capacity (ΔDLco%), the two groups were found to be comparable in terms of clinical efficacy. Both groups demonstrated similar and favorable safety profiles with respect to at least one side effect, severe side effects, gastrointestinal effects, and skin effects and mortality rates. Conclusion Based on this systematic review and meta-analysis, NAC plus pirfenidone did not