Cyclosporine therapeutic window evaluation by Chebyshev’s inequality method in kidney recipients.

The aim of this study was to identify a cyclosporine therapeutic range for kidney recipients.
The cyclosporine exposure level was based on the calculation of the mean area under the concentration-time curve AUC(0-12). The AUC(0-12) was estimated using a Bayesian estimator and a 3-point limited sampling strategy. Cyclosporine exposure levels were obtained from 3 blood samples: 0, 1, and 3h postdose; and analyses were performed using a liquid chromatography-tandem mass spectrometry method. The therapeutic window of cyclosporine was calculated by the Chebyshev’s inequality method with a 99% guarantee (α=0.01) using the IBM SPSS Statistics 20 software.
It was found that the therapeutic window of cyclosporine estimated by the Chebyshev’s inequality method and put on the AUC(0-12) exposure lies in the ranges from 2.84-3.13mgh/L with the 99% confidence for the patients with the target AUC(0-12) exposure of 3.8mgh/L (posttransplantation time >1 year). The therapeutic window of cyclosporine differs in different posttransplantation time groups: the estimated AUC exposure range in the group of patients who have a graft longer than 5 years is 2.70-2.98mgh/L, and the estimated AUC exposure range in the group of patients who have a graft for 1-5 years is 3.05-3.75mgh/L.
Chebyshev’s inequality could be an appropriate and more precise method to determine the therapeutic window for cyclosporine in kidney recipients than the target AUC(0-12) value and further studies should be conducted to evaluate patients with postoperative time <1 year.

Received 2 April 2013, accepted 15 January 2014, available online 6 June 2014.