Immunosuppressants, also called antirejection medications, are drugs that reduce or block the activity of the immune system.
Doctors use them to prevent the body from rejecting transplanted organs and bone marrow and to treat autoimmune and inflammatory conditions such as rheumatoid arthritis, lupus, psoriasis, and Crohn’s disease. Common examples include corticosteroids, calcineurin inhibitors like tacrolimus and cyclosporine, mycophenolate, and biologic drugs. Because they weaken immune defenses, they raise the risk of infections, so patients are usually monitored closely.