The Effect Of N-acetylcysteine On Stable Chronic Obstructive Pulmonary Disease: A Meta-Analysis And System Review

Objective To investigate the effects of N-acetylcysteine(NAC)on stable Chronic Obstructive Pulmonary Disease(COPD).Methods Comprehensive searches were performed of Pubmed and Medline databases obtaining the related randomized controlled trials.The included studies were selected according to inclusion criteria.A meta-analysis was performed to investigate the effect of NAC treatment on COPD.Results 12 trials involving 2691 COPD patients were included in this Meta-analysis.The result showed that both the high-dose NAC administration(RR=0.90,95%CI=0.82—0.996,p=0.041)and low-dose NAC administration(RR=0.83,95%CI=0.69—0.99,p=0.043)reduced the number of patients with at least one exacerbation.And only the therapy lasting over or equal to six months showed a significant decrease in number of patients at least one exacerbation(RR=0.83,95%CI=0.71—0.96,p=0.015).NAC showed no benefit in exacerbationrate(SMD=-0.02,95%CI=-0.29—0.26,p = 0.911),and forced expiratory volume in one second(FEV1)(SMD=0.15,95%CI=-0.04—0.33,p = 0.13),Forced Vital Capacity(FVC)(SMD=0.52,95%CI=-0.21—1.26,p =0.161),and inspiratory capacity(IC)(SMD=-1.38,95%CI=-4.65—1.90,p = 0.410).NAC was showed to improve the self-assessment(RR=1.96,95%CI=1.39—2.77,p=0.000),but not the quality of life(SMD=0.04,95%CI=-0.14—0.22,p = 0.684).The analysis of drug adverse effects happened in NAC group showed no statistical significance compared with control group(RR= 1.13,95% CI=0.86–1.48,p = 0.384),without the influence of does and duration.Data was not given enough to investigate the effect of NAC to antibiotics treatment,exacerbation duration,and hospital admissions.Conclusions High and low-dose NAC therapy over six months was effective and safe in decreasing the number of patients at least one exacerbation and improve the self-assessment.NAC showed no effect to FEV1 and FVC,IC and quality of life,but further researches are needed.