[Acetylcysteine in the treatment of severe COPD].

Oxidative stress plays a role in the pathogenesis and progression of chronic obstructive pulmonary disease (COPD). Oxidants cause structural changes in essential components of the lung, leading to irreversible damage of both the parenchyma and the airway walls. Acetylcysteine is a precursor of glutathione, an important antioxidant in the lung with a protective effect against internal and external toxic agents. In placebo-controlled studies, maintenance therapy with acetylcysteine in patients with chronic bronchitis (usually also COPD) reduced the viscosity of the sputum, the severity of coughing, the number of bacteria in the airways, the number and severity of influenza-like episodes, the number of exacerbations and the number of readmissions. In studies among COPD-patients, acetylcysteine had no effect on the downward trend of the FEV1 but did improve the functional residual capacity; itaffected the number of exacerbations only in those patients who were not on inhaled corticosteroids. The agent may well deserve a place in the treatment of patients with severe COPD who have frequent exacerbations and are not using inhaled corticosteroids.