Dynamics of tacrolimus levels in renal transplant recipients

We studied 35 medical histories of renal transplant recipients who underwent kidney transplantation in the surgical department (transplantation, reconstructive and endocrine surgery) of RRCRM&HE in Gomel. Tacrolimus concentrations were assessed on days 3, 10, and 30 after kidney transplantation. The tacrolimus C0 (zero concentration) level was determined fasting, before the morning administration of medications. Among kidney transplant recipients, there were 19 (54,3%) men and 16 (45,7%) women. The mean age was 42,7±2,0 years [95% CI 38,58; 46,73]. Before transplantation, 91,4% of patients were on programmed hemodialysis and 8.6% on peritoneal dialysis. All patients received triple immunosuppressive therapy: a calcineurin inhibitor (tacrolimus), antiproliferative drugs (azathioprine or mycophenolate mofetil), and prednisolone. Tacrolimus was administered at a dose of 0,1 mg/kg per day. According to our data, the concentration of tacrolimus on day 3 was 5,2 [4,1; 5,5] ng/ml, on day 10 it was 5,1 [2,5; 7,4] ng/ml (p3,10 = 0,809), on day 30 after surgery the tacrolimus level reached 8,2 [4,6; 10,2] ng/ml (p10,30 = 0,0007 and p3,30 = 0,027). Thus, when tacrolimus was administered at recommended doses, 8,6% of renal transplant recipients failed to achieve concentrations exceeding 4 ng/ml one month after surgery. Moreover, on day 30 of the postoperative period, the concentration of tacrolimus exceeded 7 ng/ml in 71% of renal transplant recipients.