Similar clinical outcomes of extended-release tacrolimus and immediate-release tacrolimus were found from the pooled results of well-designed randomized controlled studies, in which most of the included kidney transplant recipients were at low immunologic risk, while little is known about clinical outcomes of extended-release tacrolimus in comparison with immediate-release tacrolimus among high immunologic risk recipients.

One-third lower risk of rejection at 1-year post-kidney transplant was observed among recipients who received extended-release tacrolimus compared to immediate-release tacrolimus when data were pooled from available observational studies in which wide spectrum of kidney recipients actually using tacrolimus therapy in routine clinical care were included.

The quality of currently available observational reports is considered sub-optimal; well-designed studies with longer time follow-up would be useful for optimizing tacrolimus therapy in kidney transplant recipients.