Extended release versus immediate release tacrolimus in kidney transplant recipients: a systematic review and meta-analysis

PurposeTo compare the estimated glomerular filtration rate (eGFR) at 12months together with other outcomes among adult kidney transplant recipients (KTRs) who received extended release, once daily tacrolimus (ER-Tac) compared to those who received the immediate release, twice daily tacrolimus (IR-Tac) administration.MethodsIn accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement, we systematically reviewed all randomized controlled trials (RCTs) that compared clinical outcomes between ER-Tac versus IR-Tac in KTRs. The systematic searches were conducted on PubMed, EMBASE, Cochrane Register of Controlled Trials, Scopus, Web of Science, and CINAHL without language restriction. The trials registered and reference lists were also searched and reviewed. Data were extracted for eGFR, serum creatinine (Scr), creatinine clearance (CrCl), biopsy-proven acute rejection rate (BPAR), graft survival, and overall patient survival at different times over 24months after kidney transplant (KT). A meta-analysis was performed to integrate the results from eligible studies.ResultsFrom 1145 articles screened, 11 RCTs were included. The pooled results of included RCTs showed no significant difference of eGFR at 12months between ER-Tac and IR-Tac groups (four trials, n=1738; mean difference -0.77mL/min/1.73m(2), 95% CI: -2.41 to 0.87; p=0.56; I-2=0%). Comparing between the two tacrolimus formulations, there were no significant differences of eGFR, CrCl, Scr, BPAR, graft survival, and patient survival at different times over 4years after transplantation.ConclusionsBased upon currently available evidences in KTRs, the impact on kidney allograft function appears to be comparable between ER-Tac and IR-Tac.