RESUMEN
1. There are still no studies examining the relationship between body composition and tacrolimus pharmacokinetics in liver transplantation recipients. We aimed to investigate the influence of body composition on tacrolimus pharmacokinetics in liver transplantation recipients.2. Body composition was measured in 80 patients who underwent liver transplantation at Tianjin First Central Hospital, China, between 2015 and 2018. Blood concentrations of tacrolimus were collected from therapeutic drug monitoring data. Pharmacokinetic model fitting and Bayesian estimation were performed using nonlinear mixed-effects modeling (NONMEM) and SPSS was used to examine the effect of body composition on tacrolimus pharmacokinetics.3. The apparent volume of distribution (V/F) and clearance (CL/F) of tacrolimus were 179 L and 15.4 L/h, respectively. In liver transplantation recipients with percentage body fat (PBF) ≥ 30%, the apparent V/F of tacrolimus is lower than that in liver transplantation recipients with PBF < 30% at 1 week after liver transplantation.4. The new finding is important due to the severe adverse effects of tacrolimus. In clinical practice, an effective dosage adjustment of tacrolimus may need to be considered in patients with PBF ≥ 30% at 1 week after liver transplantation.