Abstract
A new immunosuppressive agent FK 506 inhibits rejection of allografts at lower doses than Cyclosporine in experimental animals. On the other hand, FK 506 shows drug-toxicity including anorexia and vasculitis in the dog. Clinical studies at the University of Pittsburgh showed both immunosuppressive potency and side-effects of FK 506. Combination treatment with FK 506 and Cyclosporine or FK 506 and RS-61443 reduced minimum effective doses of both agents. In addition to enhancement of immunosuppressive potency by the combination treatment, vasculitis which was frequently observed at a low dose treatment with FK 506 became infrequent by an additional treatment with a low dose of Cyclosporine. The data presented here suggest usefulness of combination treatment with FK 506 and other immunosuppressive agents to enhance the immunosuppressive potency and to reduce sideeffects.
