The efficacy of N-acetylcysteine in the management of chronic obstructive pulmonary disease: a systematic review and meta-analysis.
N-acetylcysteine may reduce acute exacerbations in COPD patients, but it does not significantly improve lung function or quality of life.
Where it sits
this study against the rest of the glutathione (gsh) corpusSummary and findings
This systematic review evaluated the efficacy and safety of N-acetylcysteine (NAC) in patients with chronic obstructive pulmonary disease (COPD). A total of 2,856 patients across 14 randomized controlled trials were analyzed. NAC was associated with a reduced incidence of acute exacerbations but did not significantly improve pulmonary function or quality of life measures.
Abstract
<h4>Introduction</h4>This study aimed to evaluate the efficacy and safety of N-acetylcysteine (NAC) in patients with chronic obstructive pulmonary disease (COPD).<h4>Methods</h4>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.<h4>Results</h4>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], <i>P</i> = 0.006). Subgroup analysis by NAC dosage showed that low-dose NAC (≤600 mg/day) was associated with a lower risk of acute exacerbations (RR = 0.84, 95% CI [0.73-0.97], <i>P</i> = 0.02), whereas high-dose NAC (>600 mg/day) showed no statistically significant benefit (RR = 0.88, 95% CI [0.73-1.06], <i>P</i> = 0.19). In addition, NAC did not significantly improve pulmonary function, including forced expiratory volume in one second (FEV1) and forced vital capacity (FVC), St. George's Respiratory Questionnaire scores, or glutathione (GSH) levels. NAC was also not associated with an increased risk of adverse events compared with the control group.<h4>Conclusions</h4>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.
Background
Chronic obstructive pulmonary disease (COPD) is a progressive lung disease characterized by increasing breathlessness. N-acetylcysteine (NAC) is an antioxidant that has been proposed to have a role in managing COPD due to its mucolytic properties and potential to reduce oxidative stress. This systematic review and meta-analysis aims to consolidate existing evidence regarding the efficacy of NAC in COPD management, which is critical given the disease's impact on quality of life and healthcare costs.
Methods
The study design is a systematic review and meta-analysis, which typically involves a comprehensive search for relevant studies, followed by statistical analysis of pooled data. The specific population, sample size (n), dose of NAC, duration of treatment, and primary versus secondary outcome measures are not reported in the abstract.
Results
Not reported in abstract.
Interpretation
Without specific numeric findings, it is challenging to compare the results of this meta-analysis to existing literature on NAC and COPD. Previous studies have shown mixed results regarding the clinical significance of NAC in COPD, and without detailed outcomes, it is difficult to ascertain whether the findings of this review provide new insights or confirm existing knowledge. The lack of detailed reporting also raises concerns about potential confounding factors that may influence the conclusions drawn.
Key findings
- Not reported in abstract.
Limitations
- Not reported in abstract.
- Lack of specific numeric findings limits assessment of efficacy.
- Potential for publication bias not addressed.
- No details on study quality or heterogeneity provided.