Optimizing tacrolimus therapy in the maintenance of renal allografts: 12-month results.

BACKGROUND: The determination of optimal tacrolimus (TAC) trough levels is needed to prevent adverse effects of calcineurin inhibitors. METHODS: Stable transplant recipients currently receiving cyclosporine (CsA) were assigned randomly (1:1:1) to continue CsA (target trough level of 50-250 ng/mL); or convert to "reduced" TAC (target trough level 3.0-5.9 ng/mL) or "standard" TAC (target trough level 6.0-8.9 ng/mL). RESULTS: At 12 months, there was a significant improvement in renal function in the reduced TAC versus CsA group with lower serum creatinine (P=0.004) and cystatin C (P<0.001), and higher estimated creatinine clearance (P=0.017). However, there were no statistically significant differences in any renal parameter in the standard TAC versus CsA group. Total and low-density lipoprotein cholesterol were significantly reduced in both TAC groups versus the CsA group (P<0.001). Patient and graft survival and episodes of biopsy-confirmed acute rejection were similar for all treatment groups, and no statistically significant differences were observed between groups in the incidence of new-onset diabetes or cardiac conditions, or in the prevalence of hyperglycemia, hypertension, or hyperlipidemia among patients who did not have these conditions at baseline. Alopecia developed more commonly among TAC-treated patients than CsA-treated patients (P<0.001). CONCLUSIONS: Compared with CsA continuation, conversion to reduced TAC target trough concentrations resulted in significantly improved renal function without increasing the risk of rejection. Conversion to TAC, regardless of target concentration, resulted in improved serum lipid profiles in kidney transplant recipients at 12 months.