Renal Function Evaluation After Reduction of Cyclosporine A Dose in Renal Transplant Patients

The usual-exposure level was based on the mean area-under-the-concentration-time curve (AUC0-12h). In the usual-exposure group, the cyclosporine AUC0-12h target was 4.3 (3.5 to 4.8, range) mg•h/L and in the low-exposure group the target was 50% or 2.2 (2.0 to 2.6, range) mg•h/L. Ranges were asymmetrical for safety reasons, i.e., to prevent the occurrence of rejection in the low-exposure arm and nephrotoxicity in the usual-exposure arm.The AUC 0-12h was estimated using a Bayesian estimator and a three-point limited sampling strategy (0, 1, and 3 hours). A computer program was used to calculate the dose adjustment required to reach the therapeutic target. Doses were adjusted in increments of 25% to reach the target within 2 months. Cyclosporine AUC0-12h was determined every 2 months.