The role for N-acetylcysteine in the management of COPD

Abstract

Oxidative stress has been implicated in the pathogenesis and progression of COPD. Both reactive oxidant species from inhaled cigarette smoke and those endogenously formed by inflammatory cells constitute an increased intrapulmonary oxidant burden. Structural changes to essential components of the lung are caused by oxidative stress, contributing to irreversible damage of both parenchyma and airway walls. The antioxidant N-acetylcysteine (NAC), a glutathione precursor, has been applied in these patients to reduce symptoms, exacerbations, and the accelerated lung function decline. This article reviews the available experimental and clinical data on the antioxidative effects of NAC in COPD, with emphasis on the role of exhaled biomarkers.

Figure 1

Absence of any exacerbation with oral N-acetylcysteine (NAC) or placebo (P) in patients with COPD and/or chronic bronchitis. Each symbol represents one trial. Symbol sizes are proportional to trial sizes. Arrows are weighted means. -------- = line of equality. Source: Stey et al. 2000. The effect of oral N-acetylcysteine in chronic bronchitis: a quantitative systematic review. Eur Respir J, 16:253–62. Copyright © 2000. Reproduced with permission of the European Respiratory Society Journals Ltd.