Abstract

Kidney transplantation is the most recommended treatment for patients with end-stage kidney disease. The major problem faced with transplantation is allograft rejection, which can be prevented by administering immunosuppressants like tacrolimus. Tacrolimus level exhibits wide variability among individuals, making therapeutic drug monitoring important. This study aimed to understand the dosing protocol of tacrolimus in kidney transplant patients and to assess the relationship between dosage and concentration levels, in the absence of information on CYP3A5 genetic polymorphism. It was a retrospective observational study including 90 patients from a tertiary care teaching hospital, who were classified into two categories, followed from the transplantation and nFFT. Data were collected from in-patient files as well as electronic medical records. This study found that tacrolimus levels were proportionately increasing from 4 to 15 ng/ml with doses. Average initial doses were high (4.34 ± 1.73 mg) and tapered to (3 ± 0.46 mg) over the visits. There were deviations observed from anticipated levels in a certain number of patients, indicating a need for genotype testing before tacrolimus dosing to accurately determine initial doses. Including genetic data would be an appropriate measure for accurate dosage adjustment, especially during the initial stages post kidney transplant.

Key words: Tacrolimus, Kidney transplantation, tacrolimus trough concentrations, inter-patient variability.