Conversion From Prograf to Advagraf Among Kidney Transplant Recipients Results in Sustained Decrease in Tacrolimus Exposure

Background. Advagraf is a slow release form of tacrolimus with once-daily formulation. The potential advantages of Advagraf are better adherence and a safer profile by avoiding toxic peak concentrations. In this study, we evaluated the required daily doses of tacrolimus and subsequent blood levels on conversion from Prograf to Advagraf among kidney transplant recipients. Methods. We retrospectively reviewed data from 55 patients for whom a switch from Prograf to Advagraf was identified. Tacrolimus daily doses and concomitant blood levels were analyzed at several time points ranging from 3 months before to 6 months after conversion. Results. We observed a significant increase in tacrolimus daily doses, starting with a dose of 0.063 mg/kg of Prograf, increasing up to 0.081 mg/kg of Advagraf at 6 months (P < 0.0001). After conversion, we observed a quick and sustained decrease in trough tacrolimus levels, decreasing from 8.05 ng/mL at day 0 to 6.30 ng/mL at day 180 (P = 0.0009). At 6 months, 35% of patients experienced a decrease in trough levels of more than 30%. Creatinine values remained stable over time, and no patient experienced an acute rejection episode. Conclusions. Contrary to the manufacturer instructions, we found a significant decrease in tacrolimus exposure after switching to Advagraf. Therefore, the switch from Prograf to Advagraf should be performed under close medical supervision.