Roflumilast (and its active metabolite, roflumilast N-oxide) increases cyclic adenosine-3?, 5?-monophosphate (cAMP) in lung cells by inhibiting PDE4. Increased cAMP activates PKA, which inactivates transcription factors involved in inflammation. Romflumilast also decreases the amount of sputum neutrophils and eosinophils in COPD patients.
Roflumilast is a phosphodiesterase-4 (PDE-4) inhibitor which, due to its selective inhibition of the PDE4 isoenzyme, has potential antiinflammatory and antimodulatory effects in the pulmonary system. It is thought that the increased levels of intracellular cyclic AMP are responsible for the therapeutic actions of Roflumilast.