[Immunosuppressants].

In recent years, novel immunosuppressive drugs applies to various autoimmune diseases and the evidences increase. Since immunosuppressive drugs inhibit nonselectively the whole immune system, there are possibilities that infection may be induced by decreasing the immunity against pathological agents and malignancy may develop by suppressing immune surveillance. In order to use the immunosuppressants safely and effectively, we should obey the indication and dosage, and be familiar with the side effects. It is also important to take informed consent from patients after explaining the benefit and risk. Therefore, the doctors who are going to use immunosuppressive drugs must know well about the indication, the side effects, the metabolism and the action mechanisms of those drugs.