Abstract
COVID‐19 has spread globally, affecting almost 160 million individuals. Elderly and pre‐existing patients (such as diabetes, heart disease and asthma) seem more susceptible to severe illness with COVID‐19. Roflumilast was licensed for usage in the European Union in July 2010 as a phosphodiesterase‐4 (PDE4) inhibitor. Under preclinical studies, roflumilast has been shown to decrease bleomycin‐induced lung fibrosis, lung hydroxyproline and right heart thickening. The current study reviewed existing data that the PDE‐4 inhibitor, a roflumilast, protects renal tissues and other major organ systems after COVID‐19 infection by decreasing immune cell infiltration. These immune‐balancing effects of roflumilast were related to a decrease in oxidative and inflammatory burden, caspase‐3 suppression and increased protein kinase A (PKA)/cyclic A.M.P. (cAMP) levels in renal and other organ tissue.