Tacrolimus Dosing in a Patient With Excellent Renal Function?
The patient is a kidney transplant recipient who showed excellent renal function immediately postoperatively. The patient is taking tacrolimus (TAC) 0.27 mg/kg/day, but the trough level has been 6-6.5 ng/mL for 10 days. The serum creatinine level is stable at 0.7 mg/dL. Should I increase the TAC dose even though the patient's renal function is excellent?
The appropriate level of postoperative immunosuppression for a given patient is a clinical judgment that takes into account the risk factors present in the donor and recipient. In most studies of TAC immunosuppression, the initial early target levels for prevention of rejection were 10-15 ng/mL. This may need to be modified in individual cases depending on the risk profile of the donor and recipient and the concomitant medications used for immunosuppression.
The greatest donor risk for rejection is delayed graft function, which is not present in this patient. Recipient risk factors that lead to a poorer outcome are black race, retransplantation, younger age, HLA mismatch, sensitization prior to transplant, and obesity.
In this case, if the patient is younger, obese, or has higher immunologic risk, I would increase immunosuppression as appropriate. If the patient is older and has a lower immunologic risk, the TAC level may be adequate, especially if mycophenolate mofetil and prednisone were used.