Background and importance Tacrolimus (TAC), a calcineurin inhibitor, is indicated in renal transplantation, and its monitoring is important due to its pharmacokinetic variability.
Aim and objectives To describe the demographic, clinical and pharmacokinetic characteristics of patients in immediate post-renal transplantation in treatment with TAC.
Material and methods Retrospective observational study carried out in a third-level general hospital.All patients with renal transplantation between September 2019 and September 2021 were included. The following variables were collected at immediate transplantation: demographic (sex, age), anthropometric (weight, height, body mass index (BMI)), monitoring-related (TAC concentration, ConTAC, corresponding to the first monitoring and at which optimal levels are reached, time relapsed from the start of TAC to the first level and the optimal level, number of determinations), clinical (creatinine(Cr) and renal clearance (ClCr) on the day of transplantation and day +7) and pharmacotherapeutics (antibody administered). Two protocols depending on the immunological risk were applied. Low-risk protocol (LR): basiliximab 20 mg on day 0 (day of transplantation) and on day +4, with immediate release TAC (single pre-transplant dose and maintenance dose). High-risk protocol (HR): thymoglobulin 1–1.5 mg/kg/day for 5–7 days and at the end, start with TAC. The target therapeutic interval of TAC in the first month post-renal transplant used was 10–15 ng/mL and the TAC dosage used was 0.15 mg/kg/day orally.The data collected were extracted from the GestLab and OrionClinic12 computer programs.
Results Thirty five patients were analysed, 57% men and 43% women with a mean age of 60±13 and 57±11years, respectively. Demographic variables, men: mean weight 78±11 kg, height 1.69±0.08 m and BMI 27±3 kg/m2, women: mean weight 67±12 kg, height 1.52±0.12 m and BMI 30±7 kg/m2). Eighteen patients (51.43%) were considered LR, receiving basiliximab + mean pre-transplant TAC dose of 10 mg and 17 patients (48.57%) as HR, receiving thymoglobulin. Mean TAC dosing regimen until first monitoring, with a mean time of 2 days: 7.25 mg/12 hours in LR and 6.14 mg/12 hours in HR. Mean total dose of TAC up to first monitoring: 33.47±13.42 mg in LR and 19.29±8.03 mg in HR. At first monitoring: LR, mean ConTAC of 22.89±8.04 ng/mL (83.3% >15 ng/mL, 11.11% <10 ng/mL, 5.55% 10–15 ng/mL); HR, mean ConTAC of 14.59±8.87 ng/mL (47.05% >15 ng/mL, 35.3% <10 ng/mL, 17.65% 10–15 ng/mL). Mean number of determinations to reach target level: 3 in LR and HR, with a mean time of 6 days in LR and 7 days in HR. Mean Cr value on transplant day and day +7: 5.9±2.7 mg/dL and 3.48±2.1 mg/dL, with mean ClCr of 10.73±5.14 mL/min and 26.8±19.76 mL/min, respectively.
Conclusion and relevance Pharmacokinetic monitoring of TAC is useful in immediate renal transplantation since a high percentage of patients present concentrations outside the target therapeutic range in the first determination. Further studies are needed to optimise the initial TAC dosage in this type of patients.
Conflict of interest No conflict of interest
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.