Twice daily N-acetylcysteine 600 mg for exacerbations of chronic obstructive pulmonary disease (PANTHEON): a randomised, double-blind placebo-controlled trial

Zheng JP

Published in The Lancet Respiratory Medicine

Methodology

Prospective, randomised, double-blind, placebo-controlled parallel-group trial (ChiCTR-TRC-09000460) at 34 hospitals; stratified by regular inhaled corticosteroid use; N-acetylcysteine 600 mg twice daily or matched placebo for 1 year with annual exacerbation rate as primary endpoint.

Key Findings

1006 patients aged 40-80 with moderate-to-severe COPD at 34 Chinese hospitals were randomised to N-acetylcysteine 600 mg twice daily (n = 504) or placebo (n = 502) for one year. Exacerbations fell from 1.49 per patient-year on placebo to 1.16 on N-acetylcysteine (risk ratio 0.78, 95% CI 0.67-0.90; p = 0.0011). Tolerability was similar, with adverse events in 29% of the N-acetylcysteine group versus 26% of placebo and comparable serious events (48 versus 46).

Conclusions

Our findings show that in Chinese patients with moderate-to-severe COPD, long-term use of N-acetylcysteine 600 mg twice daily can prevent exacerbations, especially in disease of moderate severity.

Limitations

Conducted entirely in Chinese patients with moderate-to-severe disease, so generalisability to other populations and to mild COPD is untested; the trial was funded by the manufacturer of the study drug.