Therapeutic Drug Monitoring of Cyclosporine Neoral in de Novo Chinese Cardiac Transplant Recipients Treated with an Everolimus-Cyclosporine Immunosuppressive Regimen

Abstract

This study determined cyclosporine Neoral (CsA) pharmacokinetics and the accuracy of a limited sampling strategy to predict the 12-hour CsA area-under-the-curve (AUC) to provide a practical method for more accurate therapeutic drug monitor of CsA among de novo Chinese heart transplant recipients treated with an everolimus-CsA immunosuppressive regimen. Methods Blood samples were collected at 0, 0.5, 1, 2, 3, 4, 6, 8, 10, and 12 hours after oral administration of CsA in six de novo heart recipients receiving a CsA, everolimus, and methylprenisolone immunosuppressive regimen after rabbit antithymoglobulin sequential immuno-induction. We analyzed the pharmacokinetics of the first dose (PK-1) and steady state dose (PK-2) at 1 month after transplantation. The accuracy of a single-point sampling method to predict the AUC was generated by linear regression analyses. Results The t max and dose-normalized C max of PK-1 and PK-2 were similar. The correlations in single-point blood levels of PK-1 to predict the AUC 0–∞ were much lower than the corresponding sampling times in PK-2. In PK-2 study, C4 had the best correlation ( r 2 = 0.913, P = .003) to predict AUC 0–12. In addition, the trough concentrations, C 0 ( r 2 = 0.875, P = .006) and C 12 ( r 2 = 0.783, P = .02) also showed good correlations. C2 had insufficient correlation to predict AUC 0–∞ in PK-1 or AUC 0–12 in the PK-2 study. In conclusion, the absorption of CsA was similar during PK-1 and PK-2. At steady dose, C4 had the best single-point correlation to predict AUC 0–12. Trough blood levels may be more practical in clinical use to monitor CsA.