The efficacy of N-acetylcysteine in the management of chronic obstructive pulmonary disease: a systematic review and meta-analysis.

Introduction: This study aimed to evaluate the efficacy and safety of N-acetylcysteine (NAC) in patients with chronic obstructive pulmonary disease (COPD). Methods: This systematic review was registered in PROSPERO (CRD42024597263). In February 2026, a systematic search of PubMed, Embase, Web of Science, and the Cochrane Library was conducted to identify eligible published studies. The methodological quality of the included studies was assessed using the Cochrane Collaboration's risk-of-bias tool. Statistical analyses, including the generation of forest plots, were performed using Review Manager software. Results: Fourteen randomized controlled trials involving 2,856 patients were included in the final analysis. The primary analysis of acute exacerbations included 2,609 participants, with 1,295 patients in the NAC group and 1,314 in the control group. Compared with the control group, NAC was associated with a reduced incidence of acute exacerbations in patients with COPD (risk ratio (RR) = 0.87, 95% confidence interval (CI) [0.79-0.96], Conclusions: These findings suggest that NAC may reduce the risk of acute exacerbations in patients with COPD without increasing drug-related adverse events. However, the available evidence does not indicate clear benefits for pulmonary ventilation, quality of life, or GSH levels. Further high-quality, large-scale, and rigorously designed randomized controlled trials are needed to confirm these findings.