Clinical use of FK 506 in liver transplantation.

In controlled clinical trials, primary immunosuppression with FK 506 has been shown to be comparable to a cyclosporine-based regimen for patient and graft survival following liver transplantation. FK 506 was superior to cyclosporine for treating acute, steroid-resistant, and refractory rejection. FK 506 also has been shown to be effective rescue therapy in patients with refractory rejection on conventional immunosuppression following liver transplantation. Generally, FK 506 allows the use of lower doses of corticosteroids and earlier discontinuation of azathioprine than does cyclosporine. In these clinical trials, FK 506 was associated with an increased incidence of side effects, in particular nephro- and neurotoxicity and abnormal glucose metabolism. However, preliminary results from a 2-year follow-up indicate that FK 506 and cyclosporine are comparable with respect to safety and tolerability. As increased experience is gained with the use of FK 506 for liver transplantation, the efficacy and safety profile of FK 506 should improve.