Once-daily tacrolimus in living donor liver transplant recipients

Once-daily tacrolimus (denoted here simply as OD) is a recently developed extended-release drug formulation. The purpose of the present study was to pharmacokinetically evaluate tacrolimus exposure and determine the feasibility of its de novo use in liver transplant recipients in the perioperative period. This was an open-label, single center study. Eligible patients were 18 to 65 years of age in the perioperative period after a liver transplant. Patients were initially treated with intravenous tacrolimus and then converted to the 10x milligram-for-milligram daily dose of OD administered once daily. Twenty-four-hour pharmacokinetic profiles were obtained on day 7 after the conversion. Laboratory and safety parameters were also evaluated. A total of 9 patients received OD, were successfully converted, and provided pharmacokinetic profiles. Intravenous tacrolimus and OD resulted in similar areas under the curve for 24 h (AUC(0-24)) of tacrolimus. OD was well tolerated with a safety profile comparable to that of intravenous tacrolimus. The AUC(0-24) correlated with the minimum concentration of OD (R = 0.49). Renal and liver functions remained stable. None of the patients experienced acute rejection during the observation period. OD and intravenous tacrolimus provide equivalent drug exposure, allowing conversion of selected liver transplant recipients from intravenous tacrolimus to OD in the peri-operative period.