BACKGROUND: Prolonged-release tacrolimus (Tac QD) is widely used in organ transplantation. However, the conversion from twice-daily tacrolimus (Tac BID) to Tac QD in Japan is usually done in stable patients months or years after liver transplantation. The aim of this study was to assess the early conversion of Tac QD during liver transplant hospital stay.
MATERIAL AND METHODS: Eighteen liver transplants (excluding pediatric) were performed during 2014–2015. All cases except 2 early-expired patients were enrolled. Our standard immunosuppression is oral Tac BID and steroid taper, and we add mycophenolate mofetil if indicated. Conversion criteria from Tac BID to Tac QD were: 1) relatively stable liver function with stable trough level by oral Tac BID, and 2) good general condition (no or well-controlled complications). We did not fix the exact conversion date because each patient’s recovery was different. Dose conversion rate from Tac BID to Tac QD was set at 1:1.
RESULTS: The median number of conversion days after liver transplant was 27 days. Sixty-two percent of patients were converted within 4 weeks after liver transplant, and 56% were discharged from the hospital within 2 weeks after conversion. The comparison of the last week of Tac BID and the first week of Tac QD revealed that the mean tacrolimus trough level declined by 30.4%, resulting in the 26.2% tacrolimus dose increase during the first 2 weeks after conversion. Adverse events after conversion were limited, and all patients show normal liver function to date.
CONCLUSIONS: Early Tac QD conversion is safe and feasible, but its long-term effects need further investigation.

Keywords: Immunosuppression, Liver Transplantation, Tacrolimus