ABSTRACT
Objective To evaluate the efficacy and safety of tacrolimus extended-release (Tac-ER) in the early stage after kidney transplantation. Methods Clinical data of 68 recipients undergoing kidney transplantation from 34 pairs of renal allografts were retrospectively analyzed. Two recipients who received bilateral kidneys from the same donor were treated with Tac-ER (Tac-ER group) and tacrolimus immediate-release (Tac-IR) (Tac-IR group) as one of the basic immunosuppressant. The changes of tacrolimus dosage and blood concentration, intra-patient variability (IPV), renal function, incidence of acute rejection, recipient and allograft survival rates and adverse events were statistically compared between two groups. Results The average daily dose of tacrolimus in the Tac-ER group was significantly higher than that in the Tac-IR group (F=8.386, P=0.005). In the Tac-ER group, the mean trough concentration at postoperative 4 d was (6.14±4.04) ng/mL, did not reach the target concentration, significantly lower than (9.41±5.47) ng/mL in the Tac-IR group (F=7.854, P=0.007). In the Tac-ER group, the IPV of trough concentration of tacrolimus within postoperative 1 month was significantly higher than that in the Tac-IR group (0.44±0.15 vs. 0.36±0.12, P=0.032). At postoperative 6 months, there was no significant difference in the renal function between two groups [serum creatinine level was (126±26) μmol/L vs. (120±28) μmol/L, and the estimated glomerular filtration rate was (56±13) mL/(min·1.73 m2) vs. (60±15) mL/(min·1.73 m2), both P > 0.05]. The allograft and recipient survival rates were 100% in both groups. The incidence of acute rejection within postoperative 1 month was 18% in the Tac-ER group and 3% in the Tac-IR group, with no significant difference (P > 0.05). The overall incidence of adverse events was 94% in the Tac-ER group and 97% in the Tac-IR group, with no significant difference (P > 0.05). Conclusions The efficacy and safety of Tac-ER are equivalent to those of Tac-IR, whereas a higher dose of Tac-ER should be orally given to reach the blood concentration similar to that of Tac-IR. During early-stage drug treatment, Tac-ER should be orally given before kidney transplantation or inittally with loading dose, aiming to increase the systemic exposure to tacrolimus early after kidney transplantation and prevent acute rejection caused by insufficient exposure.
ABSTRACT
Objective To investigate the intra-patient variability (IPV) of tacrolimus trough concentrations and its effect on serum creatinine (Scr) level in kidney transplant recipients treated with nematvir/ritonavir. Methods Clinical data of 41 kidney transplant recipients infected by SARS-CoV-2 and treated with nematvir/ritonavir were collected. The usage of nematvir/ritonavir and tacrolimus was summarized. The distribution of tacrolimus trough concentrations and the attainment rate of target concentration were analyzed. The correlation between the IPV distribution of tacrolimus trough concentrations and the changes of Scr level was determined. Results Among 41 kidney transplant recipients, 46%(19/41) were given with full- and low-dose nematvir/ritonavir, and 7%(3/41) were given with high-dose nematvir/ritonavir. Use of tacrolimus was discontinued at 24 h before nematvir/ritonavir treatment in 95%(39/41) patients, and at 24 h after use of nematvir/ritonavir in 5%(2/41) patients. Tacrolimus was given at least 3 d after the 5-d course of nematvir/ritonavir in all patients. The attainment rate of tacrolimus trough concentration was 73%(30/41), 30%(3/10), 48%(15/31), 35%(11/31) and 53%(16/30) before, during, 1 week, 2 weeks and 1 month after use of nematvir/ritonavir, respectively. The median IPV was 35%(23%, 51%). Spearman correlation analysis showed that the increase of Scr level was positively correlated with IPV (rs=0.400 7, P=0.028 2). Conclusions The attainment rate of tacrolimus trough concentration is declined in kidney transplant recipients treated with nematvir/ritonavir. The IPV of tacrolimus trough concentrations is elevated. The recipients with higher IPV are prone to an elevation in Scr level.