Efficacy of N-acetylcysteine for patients with idiopathic pulmonary fibrosis: A meta-analysis

Objective To systematically review the efficacy and safety of N-acetylcysteine (NAC) for patients with idiopathic pulmonary fibrosis (IPF). Methods We electronically searched PubMed, EMbase, The Cochrane Library (Issue 2, 2014), CNKI, WanFang Data and VIP databases from the date of establishment to February 2014 for all randomized controlled trials (RCTs) on the use of NAC in patients with IPF. Manual search in relevant journals were also performed. The data extraction and quality assessment of included RCTs were conducted by two reviewers independently. Then, meta-analysis was conducted using RevMan 5.1 software. Results A total of 13 RCTs involving 713 patients were included. The results of meta-analysis indicated that the NAC group was better than the control group in clinical effectiveness (RR=1.34, 95%CI 1.19 to 1.51, P<0.000 1). After treatment, the lung function was also improved in the NAC group than in the control group in the following index: PaO2 (MD=6.06, 95%CI 3.79 to 8.32, P<0.000 01), vital capacity (VC) (%) (MD=4.79, 95%CI 0.35 to 9.24, P=0.03) and diffusing capacity of carbon monoxide (Dlco) (%) (MD=5.74, 95%CI 2.67 to 8.81, P=0.000 2). However, no significant difference was found between groups in total lung capacity (TLC) (%) (MD=5.56, 95%CI -1.73 to 12.86, P=0.14). No serious or frequently-happened adverse effect was reported in the NAC group. Conclusion The current evidence suggests that NAC in long term use could improve clinical conditions, PaO2 and lung function of IPF patients, with less adverse effects. © 2014 Editorial Board of Chin J Evid-based Med.