Safe one-to-one dosage conversion from twice-daily to once-daily tacrolimus in long-term stable recipients after liver transplantation

Background: Once-daily tacrolimus provides better compliance for transplant recipients. However, the conversion strategies of dosage and concentration from twice- to once-daily are not well studied. The aim of this study was to investigate the dosage of conversion, follow-up strategy, and safety of conversion to once-daily tacrolimus in stable and long-term recipients after living donor liver transplantation (LDLT). Material/Methods: From January 2011 to November 2012, we selectively converted 35 stable LDLT recipients to once-daily tacrolimus based on 1-to-1 daily dose. The tacrolimus dosage, trough level, liver and renal function before conversion, 1 month, 3 months, 6 months, and 1 year after conversion were recorded. Results: Tacrolimus trough level dropped significantly after conversion (2.72±1.65 to 1.85±1.25 ng/mL, p<0.001). No biopsy- proved rejection was detected during 1-year follow-up. However, 1 recipient (2.9%) had a 0.5 mg increase due to elevated liver enzymes and clinically diagnosed rejection. No other patients required dose adjustment due to dropped tough level after conversion. Conclusions: One-to-one dosage conversion in stable LDLT recipients is a safe strategy. Dropped trough level is expected and dose adjustment is rarely required.