What is the role of roflumilast in chronic obstructive pulmonary disease

Roflumilast has been shown to reduce rates of acute exacerbation in patients with severe chronic obstructive pulmonary disease (COPD), ie, forced expiratory volume in 1 second (FEV1) less than 50% with symptoms of chronic bronchitis and a history of exacerbations. Roflumilast is a selective