PDE4A and chronic obstructive pulmonary disease: At present, bronchodilators (short-acting Beta2-agonists (SABA) and long-acting Beta2-agonists (LABA)), antimuscarinic drugs (short-acting antimuscarinics (SAMAs), and Long-acting muscarinic antagonists (LAMAs)), methylxanthines (Theophylline), anti-inflammatory agents, Inhaled corticosteroids (ICS), antibiotics, mucolytic (mucokinetics and dmucoregulators), antioxidant agents (N-acetylcysteine, carbocysteine, and erdosteine) and Phosphodiesterase-4 (PDE4) inhibitors are commonly used drugs for the treatment of COPD [1].