Objective: To investigate the efficacy and tolerability of high-dose N-acetylcysteine (NAC) in the treatment of patients with exacerbations of chronic obstructive pulmonary disease (COPD).

both dosages of NAC were superior to placebo in terms of improving lung function and clinical outcomes; (c) NAC1200 was superior to NAC600 in reducing IL-8 and difficulty of expectoration.