In this non-interventional observational study, treatment for individual subjects is determined by the investigator according to the status of individual subjects in routine clinical practice. In this circumstance, doses for each drug product will not be specified in the protocol but will be determined as appropriate by the investigator with the product label and the subject's medical condition taken into consideration.~Primary objective To evaluate the effect of Mucomyst on improvement in difficulty of expectoration symptoms in COPD patients with difficulty of expectoration.~Secondary objective To evaluate the effect of Mucomyst on improvement in quality of life and safety in COPD patients with difficulty of expectoration.
To evaluate the effect of Mucomyst nebulizer therapy on improvement in symptoms and quality of life in COPD patients with difficulty of expectoration.