Establishing Population Pharmacokinetic Model for Ethambutol on Pulmonary Tuberculosis Patients

The population pharmacokinetic model of ethambutol with covariates was built from data from 136 pulmonary tuberculosis patients recruited from 3 hospitals: Hanoi Lung Hospital, Central Hospital 74, and Central Lung Hospital. Blood samples were obtained on the 10-14th day after initiation of treatment for plasma drug analysis by LC-MS/MS method. Time - concentration data were processed by the method of non-linear mixed effect modeling on MONOLIX 2021R1 software. The final population pharmacokinetic model is a two-compartment model, sequential zero (with prior lag time Tk01) followed by first-order absorption, and linear elimination. The volumes of distribution of the central and peripheral compartments were respectively 6.73 L and 1250 L; the clearance value Cl was 45.8 L/h. Janmahasatian’s Fat-free mass and age were found to be influential to the inter-individual variability of clearance.