Impact of converting adult kidney transplant recipients with high tacrolimus variability from twice daily immediate release tacrolimus to once daily LCP-Tacrolimus

BackgroundThe influence of converting to once daily, extended-release LCP-Tacrolimus (Tac) for those with high tacrolimus variability in kidney transplant recipients (KTRs) is not well-studied. MethodsSingle-center, retrospective cohort study of adult KTRs converted from Tac immediate release to LCP-Tac 1-2 years post-transplant. Primary measures were Tac variability, using the coefficient of variation (CV) and time in therapeutic range (TTR), as well as clinical outcomes (rejection, infections, graft loss, death). ResultsA total of 193 KTRs included with a follow-up of 3.2 +/- .7 years and 1.3 +/- .3 years since LCP-Tac conversion. Mean age was 52 +/- 13 years; 70% were African American, 39% were female, 16% living donor and 12% donor after cardiac death (DCD). In the overall cohort, tac CV was 29.5% before conversion, which increased to 33.4% after LCP-Tac (p = .008). In those with Tac CV >30% (n = 86), conversion to LCP-Tac reduced variability (40.6% vs. 35.5%; p = .019) and for those with Tac CV >30% and nonadherence or med errors (n = 16), LCP-Tac conversion substantially reduced Tac CV (43.4% vs. 29.9%; p = .026). TTR significantly improved for those with Tac CV >30% with (52.4% vs. 82.8%; p = .027) or without nonadherence or med errors (64.8% vs. 73.2%; p = .005). CMV, BK, and overall infections were significantly higher prior to LCP-Tac conversion. In the overall cohort, 3% had rejection before conversion and 2% after (p = NS). At end of follow-up, graft and patient survival were 94% and 96%, respectively. ConclusionsIn those with high Tac CV, conversion to LCP-Tac is associated with a significant reduction in variability and improvement in TTR, particularly in those with nonadherence or medication errors.