Population Pharmacokinetics of Tranexamic Acid in Chinese Population Undergoing Cardiac Surgery with Cardiopulmonary Bypass.

Background: Population pharmacokinetics (PK) models could provide specific references for the formulation of personal drug delivery protocols, however, there is no population PK study of tranexamic acid (TXA) have been conducted in the Chinese population. The aim of this study was to establish a population PK model based on the data of perioperative plasma concentrations in Chinese participants, and to provide a reference for individualized administration of TXA.

Methods: Participants undergoing cardiac surgery were randomly assigned to high-dose of TXA group (a 30-mg/kg bolus, a 16-mg/kg/h maintenance dose, and a 2-mg/kg prime, n = 7) and low-dose group of TXA (a 10-mg/kg bolus, a 2-mg/kg/h maintenance dose, and a 1-mg/kg prime, n = 9). Blood samples were collected at 14 time points and the concentration of TXA was determined by liquid chromatography-tandem mass spectrometry. Modelling was performed using Phoenix NLME 8.3 software.

Results: The primary covariate identified was body weight, while no significant influence of cardiopulmonary bypass (CPB) on the PK was detected. The population estimates for clearance (CL₁), volume of the central compartment (V₁), diffusional clearance (CL₂), and volume of peripheral compartment (V₂) were 4.7 L/h, 4.9 L, 17.0 L/h, and 11.1 L, respectively, assuming a bodyweight of 70 kg.

Conclusion: This study provides the first population PK model of TXA in the Chinese population undergoing cardiac surgery with CPB. The model could serve as a reference for the future development of individualized TXA administration strategies, with target-controlled infusion (TCI) emerging as a viable option.