BANTAO Journal 2016; 14(2): 73-76; DOI:10.1515/bj-2016-0018 ________________________ Correspondence to: Nikolina Basic-Jukic, Department of nephrology, arterial hypertension, dialysis and transplantation, University hospital centre Zagreb, Kispaticeva 12, 10000 Zagreb, Croatia; E-mail:nina_basic@net.hr 73 BJ BANTAO Journal Original article Conversion from Twice-Daily to Once-Daily Tacrolimus Improves Graft Function but has no Influence on Proteinuria in Renal Transplant Recipients Nikolina Basic-Jukic, Ljubica Bubic-Filipi, Lea Katalinic, and Judita Lelas Department of nephrology, arterial hypertension, dialysis and transplantation, University hospital centre Zagreb, School of medicine, University of Zagreb and School of medicine, University of Osijek, Croatia Abstract Introduction. Tacrolimus extended-release formulation enables once-daily use. Although an increasing number of patients have been converted from twice-daily (Tac- BID) to once-daily (Tac-QD) formulation, the available information regarding the initiation and follow-up of Tac- QD is sparse. In the present study we investigated influen- ce of switch from Tac-BID or cyclosporine to Tac-QD on renal allograf function, proteinuria and protein-creati- nine (P/C) ratio. Methods. Between October 2012 and October 2014, the switch from Tac-BID or cyclosporine to tacrolimus extended-release formulation was done in 129(38% fe- male, mean age 49 years) renal transplant recipients at different time after transplantation. The analysis focused on markers of graft function (GFR, serum creatinine, pro- teinuria, P/C ratio), liver function (AST, ALT, γGT, alka- line phosphatase) and blood glucose. Clinical data were obtained at baseline (before conversion), 1 month (V1), 6 months (V6) and 12 months (V12) after conversion. Results. Both serum creatinine and GFR showed a sta- tistically significant improvement. With GFR, signify- cant improvement was observed as early as V1 and it continued to increase throughout the study period up to V12 (all between-visit changes were statistically signifi- cant). With serum creatinine, mean levels were numeri- cally decreasing throughout the follow-up period, but a significant improvement occurred at V6 and remained significant at V12 (both vs. V0 values). Proteinuria and P/C ratio did not show any significant change through the observation period. In the majority of patients, the baseline values of AST, ALT, GGT, AlP and glucose were within normal limits and did not change signifi- cantly through the observation period. Analysis of tac- rolimus C0 showed a significant decrease throughout the follow-up period, at practically all visit. This finding was paralleled by a significant tacrolimus dose decrease from baseline to V6 and V12, as well as by a signifi- cant decrease of tacrolimus dose/body weight. Conclusions. Conversion from cyclosporine or Tac-BID to extended-release Tac-QD improves graft function in renal transplant recipients, without influence on proteinu- ria or P/C ratio. Keywords: once-daily, twice-daily, tacrolimus, proteinuria, kidney transplant ______________________________________ Introduction Once-daily tacrolimus (Tac-QD) has the same active component and metabolism as twice-daily tacrolimus (Tac-BID), but is released more distally in the gastroin- testinal tract. Pharmacokinetic study performed on 40 kidney transplant recipients converted from Tac-BID to Tac-QD revealed that conversion to the QD formula- tion decreased intrapatient variability [1]. Additionaly, Tac-QD could offer the potential benefit of improved medication compliance by decreasing pill burden and thereby simplifying dosing schedule. Although an in- creasing number of patients has been converted from Tac-BID to Tac-QD formulation, the available informa- tion regarding the initiation and follow-up of Tac-QD is sparse [2-6]. Observational data are useful adjuncts to randomized, controlled trials, which clarify whether efficacy under controlled conditions translates into effec- tive treatment in everyday practice. Thus, we investi- gated influence of switch from Tac-BID or cyclospori- ne to Tac-QD on renal allograft function, proteinuria and protein-creatinine (P/C) ratio in the routine clinical practice. Materials and methods The analysis included 129 kidney transplant patients [49 (38%) female] who were at different times after trans