Table 1.
Summary of randomized, placebo-controlled controlled trials of oral N-acetylcysteine in chronic obstructive pulmonary disease.
| First Author | Study | Sample Size & Population | Intervention | Primary Outcomes | Comments |
|---|---|---|---|---|---|
| Decramer 2005 [26] |
BRONCUS | Smoking-related stable COPD (n = 523) Age 40–75 years FEV1 40–70% predicted Mean age 62 years Women 21% Current smokers 46% Mean predicted FEV1 57% |
600 mg of NAC daily or matching placebo for 3 years | No difference in FEV1 in pts (54 mL vs. 47 mL; 95% CI –25, 10); No overall difference in exacerbations per year (HR 0.99, p = 0.85) Potential reduction in exacerbation rate in pts not treated with ICS |
Dose only 600 mg once daily |
| TSE 2013 [27] |
HIACE | Smoking-related stable COPD (n = 120) Age 50–80 years FEV1 < 70% predicted value over 1 year Mean age 71 years Women 7% Current smokers 23% Mean predicted FEV1 54% |
600 mg of NAC twice daily or matching placebo for 1 year | FEF improved 25% to 75% (p = 0.037) Reduction in exacerbation frequency (0.96 vs. 1.71 times per year, p = 0.019) |
Trend towards a reduction in hospital admission rates |
| Zheng 2014 [28] |
PANTHEON | Moderate-to-severe COPD (n = 1006) Age 40–80 years FEV1 30–70% of predicted value over 1 year Mean age 66 years Women 18% Current smokers 18% Ex-smokers 58% Non-smokers 24% Mean predicted FEV1 49% |
600 mg of NAC twice daily or matching placebo for 1 year | Reduction in exacerbation frequency (1.16 vs. 1.49 per patient-year, p = 0.0011; RR 0.78, 95% CI 0.67–0.90; p = 0.0011) | Time to second exacerbation and time to third exacerbation extended No significant difference in treatment effect and ICS use |
Abbreviations: CI confidence interval, COPD chronic obstructive pulmonary disease, FEF forced expiratory flow, FEV1 forced expiratory volume in one second, HR hazard ratio, ICS inhaled corticosteroids, NAC N-acetylcysteine, pts patients, RR risk ratio.