Mucoactive drugs in the management of chronic obstructive pulmonary disease

In chronic obstructive pulmonary disease (COPD), mucus hypersecretion is considered one of the main symptoms. Recently the natural history of COPD has been better defined and chronic mucus hypersecretion is now viewed as linked to the acceleration of forced expiratory volume in one second (FEV1) decline and not merely as an "innocent disorder". In the past, mucoactive drugs were claimed to treat mucus hypersecretion. However, since most mucoactive drugs have not been evaluated in large clinical studies, European Respiratory Society and American Thoracic Society COPD guidelines discourage their use for treatment of COPD patients. Clinical trials have been often disappointing because improvement in lung function has been adopted as the main outcome, despite bronchial obstruction in COPD patients being frequently irreversible or poorly reversible. Thus, goals for treatment in COPD patients should include not only improvement in lung function, but also clinical symptoms and quality of life. Moreover, to rightly allocate these drugs in COPD management and to try to modify the natural history and progression of COPD, mucus hypersecretion might require treatment in the first stage of the disease. In conclusion, mucoactive treatments for chronic obstructive pulmonary disease patients should be re-evaluated in the future in patients selected according to demographic factors such as degree and reversibility of bronchial obstruction due to mucus hypersecretion, patient smoking habits and other socioeconomic parameters which have proved to be relevant to the progression of the disease, according to the latest recommendations for guidelines on clinical trials of mucoactive drugs in chronic bronchitis and chronic obstructive pulmonary disease.