A comparison of the extended-release and standard-release formulations of tacrolimus in de novo kidney transplant recipients: a 12-month outcome study

Background. Limited comparative data are available on the outcomes between extended-release and standard-release tacrolimus when used de novo in kidney transplant recipients (KTRs). Methods. We identified KTRs transplanted at our institution during 2009-10 routinely prescribed extended-release tacrolimus and compared them with those transplanted during 2008-09 prescribed standard-release tacrolimus. Graft function (eGFR by MDRD-7 equation) at 12 months post-transplant (primary outcome); new-onset diabetes and other cardiovascular risk factors, BK viremia incidence, acute rejection, and graft survival to 12 months (secondary outcomes) were compared by intent-to-treat analysis. Time-to-steady-state concentration and number of dose adjustments required to attain steady state were recorded. Results. There were no important demographic differences between the extended-release (N = 106) and standard-release (N = 95) cohorts. The estimated glomerular filtration rate (eGFR) at 12 months was similar (58.8 +/- 17 versus 59.2 +/- 18 mL/min/1.73 m(2), P = 0.307). There was no difference in new-onset diabetes (17 versus 20%, P = 0.581), BK viremia (10 versus 7%, P = 0.450), acute rejection (7 versus 16%, P = 0.067) or graft survival (97 versus 95%, P = 0.301). Time-tosteady state was similar (9.2 +/- 1.1 versus 8.1 +/- 4.7 days, P = 0.490) although extended-release patients required fewer adjustments to attain steady state (1.2 +/- 1.7 [0-8] versus 1.7 +/- 1.5 [0-7], P = 0.030) but a similar dose (7.2 +/- 2.4 [2-17] versus 7 +/- 2.7 [2-16] mg/day, P = 0.697). Conclusion. De novo KTRs prescribed extended-release or standard-release tacrolimus demonstrate similar 12-month outcomes.