Although high-dose N-Acetylcysteine ( NAC; Acetylcysteine; Fluimucil ) has been suggested to reduce COPD ( chronic obstructive pulmonary disease ) exacerbations, it is unclear which category of patients with COPD would benefit most from Acetylcysteine treatment.
The objective of this study was to compare the effect of high-dose Acetylcysteine ( 600 mg bid ) between high-risk and low-risk Chinese patients with COPD.
Patients with spirometry-confirmed stable COPD were randomized to treatment with either Acetylcysteine 600 mg bid or placebo in addition to their usual treatments.
Patients were followed up every 16 weeks for a total of 1 year.
Further analysis was performed according to each patient's exacerbation risk at baseline as defined by the current GOLD ( Global Initiative for Chronic Obstructive Lung Disease ) strategy to analyze the effect of high-dose Acetylcysteine in high-risk and low-risk patients.
Of the 120 patients with COPD randomized ( men, 93.2%; mean age, 70.8 ± 0.74 years; prebronchodilator FEV₁, 53.9 ± 2.0%; baseline characteristics comparable between treatment groups ), 108 ( Acetylcysteine, 52; placebo, 56 ) completed the 1-year study.
For high-risk patients ( n = 89 ), high-dose Acetylcysteine compared with placebo significantly reduced exacerbation frequency ( 0.85 vs 1.59 [ P = 0.019 ] and 1.08 vs 2.22 [ P = 0.04 ] at 8 and 12 months, respectively ), prolonged time to first exacerbation ( P = 0.02 ), and increased the probability of being exacerbation free at 1 year ( 51.3% vs 24.4%, P = 0.013 ).
This beneficial effect of high-dose Acetylcysteine vs placebo was not significant in low-risk patients.
In conclusion, high-dose Acetylcysteine ( 600 mg bid ) for 1 year reduces exacerbations and prolongs time to first exacerbation in high-risk but not in low-risk Chinese patients with COPD. ( Xagena )
Tse HN et al, Chest 2014;146:611-623