PURPOSE: Cyclosporine (CsA) dosing is traditionally based on trough levels (C0) rather than area under the concentration- time curve (AUC), although AUC correlates better with post- transplantation acute rejection and toxicity. It was reported that C2 (2-hour post-dose blood level) is an accurate single- sample marker for AUC0-4 in patients receiving CsA. No trials of C2 monitoring have been carried out in liver transplant recipients who are immunosuppressed with the combination of CsA and Mycophenolate Mofetil (MMF). The purpose of this study was to evaluate the correlation between C0, 1, 2, 3, 4 levels and AUC0-4 and define recommended target C2 in liver transplant recipients who are treated with CsA and MMF. METHODS: Thirty adult living donor liver transplant recipients were followed up 12 weeks after transplantation. CsA and MMF were administered in all recipients. CsA dose was reduced to the half level of target C0 in recipients treated solely with CsA. C0 and C2 were measured during in-patient period post-transplant. RESULTS: The best correlation between CsA concentration at various time points and the AUC0-4 was found at C2 (r2=0.931) (P<0.05). Mean C2 was 543.2+/-260.1 ng/mL (mean+/-SD). We observed complications associated with the immunosuppressants in six patients (20%). But, only one patient experienced acute rejection proven by biopsy and, there is no the graft loss and nephrotoxicity. CONCLUSION: In early post-transplant days, AUC0-4 was strongly correlated with C2. Reduced CsA dosing can be attempted in recipients who are immunosuppressed with the combination of CsA and MMF. The optimal target C2 probably can be suggested as about 543.2+/-260.1 ng/mL (mean+/-SD). During the in-patient period, C0 matched with target C2 can be decided. Target C0 can be individualized because C0 matched with target C2 differs in each recipients and C2 can't be checked routinely during the out-patient period.
Adult ; Area Under Curve ; Biopsy ; Cyclosporine* ; Humans ; Immunosuppressive Agents ; Liver Transplantation ; Liver* ; Living Donors ; Outpatients ; Transplantation* ; Transplants