In a recent randomized study of 120 patients with stable COPD, study participants, aged 50 – 80 yrs, received either 600 mg of NAC twice daily or placebo. Participants averaged 2 exacerbations and 1 COPD hospitalization during the previous year. At 1 year, there was significant improvement on Forced Expiratory Flow (FEF 25-75%) and forced oscillation technique (FOT, a significant reduction in exacerbation frequency and a tendency towards reduction in admission rate with NAC vs. placebo. No major adverse effects were reported. Researchers concluded that high-dose (1200 mg/day) NAC resulted in significantly improved small airways function and decreased exacerbation frequency in patients with stable COPD.
Tse HN et al. High-Dose N-Acetylcysteine in Stable Chronic Obstructive Pulmonary Disease: the 1 Year, Double-Blind, Randomized, Placebo-Controlled HIACE Study. 2013 Chest.