Comparison of Neoral and Sandimmun for induction and maintenance immunosuppression after kidney transplantation

We compared the mean trough level/dose (L/D) ratio, mean coefficient of variation (CV) of individual patients, and graft, patient, and rejection-free survival rates of 40 renal transplant recipients receiving Neoral (CyE) with 103 consecutive renal transplant recipients receiving Sandimmun (CyA). The mean L/D ratio on the 3rd post-transplant day (16.2 vs 11.8, P < 0.04), in the 1st week (24.6 vs 16.1; P < 0.03), and 1st month (39.1 vs 28.7; P < 0.05) were higher in the CyE group. In both groups the L/D ratio improved in proportion to the duration of time post-transplant and reached a maximum in the 3rd post-transplant month. In the early post-transplant period in particular, the number of patients achieving target levels was significantly higher, and the mean dose needed to achieve target levels lower, in the CyE group. The variation in trough levels, demonstrated by the CV, was lower in the CyE group (0.41 ± 0.14) than in the CyA group (0.62 ± 0.21; P < 0.005). Actuarial 1-year patient and graft survival rates in the CyE group were 100 % and 96 %, respectively; these were similar to the 100 % and 95 % in the CyA group. The 1-year rejection-free survival rate in the CyE group was 61 % compared to 43 % in the CyA group (P < 0.02). We conclude that it is possible to obtain higher blood trough levels at lower doses by administering CyE, particularly in the early post-transplant period. The lower variability of trough levels and the higher L/D ratio in the CyE group, which are related to improved bioavailability of CyE, may explain the lower rejection rate among these patients. In this study, the microemulsion formulation of cyclosporin (CyE) was found to be more beneficial and cost-effective as induction and maintenance immunosuppression than the conventional formulation (CyA). Received: 28 January 1997 Received after revision: 13 May 1997 Accepted: 15 May 1997