5.2. Selective and non-selective PDE4i
Because of the involvement of cAMP signaling in the pathophysiology of many inflammatory diseases, it has been proved that targeting PDE4 will resemble an effective therapeutic strategy for different inflammatory conditions, as chronic obstructive pulmonary disease (COPD), asthma, atopic dermatitis (AD), inflammatory bowel diseases (IBD), rheumatic arthritis (RA), lupus and neuroinflammation (Li et al., 2018).
Early, nonselective PDE inhibitors were discovered including theophylline and doxofylline, but, because of their associated significant adverse effects, their use had been limited.
Given that PDE4 is the only cellular pathway available for cAMP degradation (Fertig, Bracy A., 2018), therapeutic studies have been directed to develop the most selective PDE4 inhibitors, among which, Apremilast and Roflumilast are currently available (Boswell-Smith et al., 2006; Kumar et al., 2013).
6. Pharmacotherapeutic effects of Roflumilast
Since 2011, roflumilast has been approved by FDA as an anti-inflammatory drug specifically designed for many respiratory disorders mainly COPD and asthma. By time, roflumilast has been reported to exert different pharmacological activities,Figure 2 and Table 1 (Li et al., 2018).