Pharmacological mechanism of roflumilast in the treatment of asthma–COPD overlap

Xiaoli Zhang,1,* Yuqing Chen,1,* Liyu Fan,1,* Jiaqi Ye,1 Junsheng Fan,2 Xinjie Xu,1 Danming You,3 Sihan Liu,3 Xin Chen,1 Peng Luo1 1Department of Respiratory Medicine, Zhujiang Hospital of Southern Medical University, Guangzhou, China; 2Department of Respiratory Medicine, Shanghai Tenth People’s Hospital of Tongji University, Shanghai, China; 3Department of Respiratory Medicine, Nangfang Hospital of Southern Medical University, Guangzhou, China *These authors contributed equally to this work Abstract: Asthma–COPD overlap (ACO) is a type of incomplete obstructive airway disease that has a high incidence and mortality. Nevertheless, there is currently no clear definition of ACO and no effective intervention. The newly discovered phosphodiesterase-4 inhibitor, roflumilast, has shown initial efficacy for treating asthma, COPD, and ACO. The mechanism of roflumilast, however, remains unclear, and there has been no interpretation through systematic review to date. The determination of a definite mechanism of roflumilast will guide the clinician’s decisions regarding medication use, standardized diagnosis, and treatment guidelines. For this reason, we have systematically reviewed the therapeutic mechanism of roflumilast for ACO and provided reference for the clinical application of roflumilast in ACO. Keywords: asthma–COPD overlap, roflumilast, phosphodiesterase-4 inhibitors, mechanism