Apremilast inhibits an enzyme called phosphodiesterase-4, which breaks down chemical messengers in the body, these are communication modalities in the body to coordinate the immune system. When the enzyme is inhibited, less chemical messengers get broken down.
This leads to higher levels of a chemical messenger known as cyclic adenosine monophosphate. Higher levels of this chemical messenger causes the body to turn down cellular signals that increase inflammation. Therefore, Apremilast helps to reduce inflammation, joint pain and tenderness and helps normalize skin in psoriasis.