Influence of N-acetylcysteine on chronic bronchitis or COPD exacerbations: a meta-analysis

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#acetylcysteine #bronchitis-chronic #bronchodilator-agents #disease-progression #humans

Influence of N-acetylcysteine on chronic bronchitis or COPD exacerbations: a meta-analysis

Cazzola et al., 2015 | Eur Respir Rev | Meta Analysis

Citation

Cazzola Mario, Calzetta Luigino, ... Matera Maria Gabriella. Influence of N-acetylcysteine on chronic bronchitis or COPD exacerbations: a meta-analysis. Eur Respir Rev. 2015-Sep;24(137):451-61. doi:10.1183/16000617.00002215

Abstract

In order to clarify the possible role of N-acetylcysteine (NAC) in the treatment of patients with chronic bronchitis and chronic obstructive pulmonary disease (COPD), we have carried out a meta-analysis testing the available evidence that NAC treatment may be effective in preventing exacerbations of chronic bronchitis or COPD and evaluating whether there is a substantial difference between the responses induced by low (≤ 600 mg per day) and high (> 600 mg per day) doses of NAC. The results of the present meta-analysis (13 studies, 4155 COPD patients, NAC n = 1933; placebo or controls n = 2222) showed that patients treated with NAC had significantly and consistently fewer exacerbations of chronic bronchitis or COPD (relative risk 0.75, 95% CI 0.66-0.84; p < 0.01), although this protective effect was more apparent in patients without evidence of airway obstruction. However, high doses of NAC were also effective in patients suffering from COPD diagnosed using spirometric criteria (relative risk 0.75, 95% CI 0.68-0.82; p = 0.04). NAC was well tolerated and the risk of adverse reactions was not dose-dependent (low doses relative risk 0.93, 95% CI 0.89-0.97; p = 0.40; high doses relative risk 1.11, 95% CI 0.89-1.39; p = 0.58). The strong signal that comes from this meta-analysis leads us to state that if a patient suffering from chronic bronchitis presents a documented airway obstruction, NAC should be administered at a dose of ≥ 1200 mg per day to prevent exacerbations, while if a patient suffers from chronic bronchitis, but is without airway obstruction, a regular treatment of 600 mg per day seems to be sufficient.

Key Findings

The strong signal that comes from this meta-analysis leads us to state that if a patient suffering from chronic bronchitis presents a documented airway obstruction, NAC should be administered at a dose of ≥ 1200 mg per day to prevent exacerbations, while if a patient suffers from chronic bronchitis, but is without airway obstruction, a regular treatment of 600 mg per day seems to be sufficient.

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population chronic bronchitis and chronic
Sample Size 1933
Age Range See abstract
Condition See abstract

MeSH Terms

  • Acetylcysteine
  • Bronchitis, Chronic
  • Bronchodilator Agents
  • Disease Progression
  • Humans
  • Lung
  • Pulmonary Disease, Chronic Obstructive
  • Treatment Outcome

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Journal Article, Meta-Analysis, Review
  • Vertical: NAC-respiratory

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09