Pharmacokinetic-pharmacodynamic assessment of tacrolimus in liver-transplant recipients during the early post-transplantation period.

During the early post-transplantation period, the limitations of monitoring current tacrolimus dose with classic pharmacokinetics (PK) have been demonstrated in liver-transplant recipients. Evaluation of the pharmacodynamics (PD) using calcineurin activity (CNA) has been proposed to optimize tacrolimus dosing. The aim of the present study was to determine the time of maximal inhibition of CNA, to explore the relation between exposure to tacrolimus and CNA, and to analyze its variability.