- A drug used to reduce inflammation and lower the body’s immune response. It is used with other drugs to treat leukemia, lymphoma, and mycosis fungoides (a type of skin lymphoma). It is also used alone or with other drugs to prevent or treat many other conditions. These include conditions related to cancer and its treatment, such as anemia (a low level of red blood cells) and allergic reactions. Prednisone is a type of therapeutic glucocorticoid.