Chronic obstructive pulmonary disease (COPD), a common preventable and treatable disease, is characterized by persistent airflow limitation that is usually progressive and associated with an enhanced chronic inflammatory response in the airways and the lung to noxious particles or gases. Clinical diagnosis of COPD should be considered in any individual, who has dyspnea, chronic cough, sputum production, and positive history of risk factors. Pharmacologic therapy can reduce COPD symptoms, reduce the frequency and severity of exacerbations, and improve health status and exercise tolerance. After cessation of smoking and life style modification, bronchodilator therapy is the first step in COPD treatment. Beside commonly used bronchodilator the...