Comparison of pharmacokinetics and pathology for low-dose tacrolimus once-daily and twice-daily in living kidney transplantation: prospective trial in once-daily versus twice-daily tacrolimus.

BACKGROUND A prolonged-release formulation of tacrolimus (Tacrolimus QD) was developed to allow once-daily dosing and to have similar safety and efficacy profiles to twice-daily tacrolimus (Tacrolimus BID). This study compared the pharmacokinetics (PK) and renal pathology by protocol biopsy in de novo living kidney transplant recipients treated with either low-dose Tacrolimus QD or Tacrolimus BID. METHODS Between November 2009 and January 2011, 102 consecutive adult patients were randomized to receive either low-dose Tacrolimus QD or Tacrolimus BID. All patients underwent PK study and protocol biopsy on postoperative day 14. Additional protocol biopsies were performed between 6 and 12 months after renal transplantation. RESULTS During the 1-year follow up, the incidence of biopsy-proven acute rejection and toxic tubulopathy was low and similar in both groups. Twenty-four hours area under the curve (AUC0-24) was not different in both groups (285 ± 78.7 and 281 ± 62.4 ng hr/mL in Tacrolimus QD and Tacrolimus BID, respectively). C0 was well correlated with AUC0-24 in both groups and AUC0-24 between 260 and 280 in the Tacrolimus QD group was achieved by 6 to 8 ng/mL of C0. Acute nephrotoxicity was less than 10% in both groups without any clinical manifestation. CONCLUSION Clinical efficacy, safety, and PK profile of Tacrolimus QD is same as those of Tacrolimus BID.