PDE4A and chronic bronchitis: Accordingly, the use of short- and long-acting β-adrenergic receptor agonists and anticholinergics as bronchodilators and to improve mucociliary clearance, glucocorticoids to reduce inflammation and mucus production, and PDE-4 inhibitors to decrease inflammation and due to their bronchodilator properties represent the common treatment strategies for chronic bronchitis (Kim and Criner, 2013).