immunosuppressive /-səpres″iv/ , 1. adj., pertaining to a substance or procedure that lessens or prevents an immune response. 2. n., an immunosuppressive agent. The immunosuppressive drugs used most frequently to prevent allograft rejection are the interleukin 2 production inhibitors cyclosporine and tacrolimus, the cytotoxic purine antimetabolite azathioprine, the alkylating agent cyclophosphamide, and the adrenocorticosteroid prednisone. Methotrexate, cytarabine, dactinomycin, and thioguanine are also potent immunosuppressive drugs. Monoclonal antibodies against the T cell receptor (muromonab-CD3) and interleukin 2 receptors (basiliximab and daclizumab) are also administered for immunosuppression. The use of some of these agents is being explored for the treatment of autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus.
