A New Strategy of Therapeutic Drug Monitorining of Cyclosporine A Blood Levels inPatients after Renal Transplantation

Overview

Cyclosporine A (CyA), tacrolimus (FK 506), and mycophenolic acid are routinely utilised immunosupressivedrugs used in the prevention of allograft rejection and the treatment of several autoimmunediseases. The monitoring of CyA blood levels plays the most important role to individualizethe dosage regiment and to minimize acute rejection risk and drug toxicity. Inadequate low CyAdoses and levels may result in the rejection of transplanted organs.Toxic levels of CyA are associatedwith many serious side effects, including nephrotoxicity, hepatotoxicity, and a range of othercomplications. In the period of 1999–2002, 12 859 analyses of whole blood CyA levels were performedat our Department of Clinical Biochemistry. The aim of the present paper is to establish a newmonitoring strategy of CyA that consists in the use of a single sampling point at 2 hours postdoseand the estimation of blood concentration (C2). For the transplant patient, C2 monitoring isa significantly much better predictor of drug exposition and pharmacokinetic estimation than thetrough concentration monitoring before the next dose (C0) used until now. The C2 monitoringstrategy reduces the incidence and severity of both acute organ rejection and cyclosporine A toxicity.

Key words:
cyclosporine A – therapeutic drug monitoring – AUC – C2 monitoring