Population pharmacokinetics of vancomycin in Thai patients

Population pharmacokinetics of vancomycin in Thai adult patients was determined by non-linear mixed-effects approach using 319 vancomycin serum concentrations from 212 patients. The data were best fitted by a two-compartment model and it was used to examine the effect of patient characteristics on the vancomycin pharmacokinetics. In the final model, there was a linear relationship between vancomycin clearance, CL (L/h), and creatinine clearance calculated by Cockcroft-Gault equation, CLCr (mL/min): CL=0.044 × CLCr. Meanwhile, volume of central compartment, V 1 (L), was linearly related with the age (years old): V 1 =0.542 × Age. Intercompartment clearance (Q) and volume of peripheral compartment (V 2) was 6.95L/h and 44.2L, respectively. The interindividual variability for CL, V 1, Q, and V 2 was 35.78, 20.93, 39.50, and 57.27%, respectively. Whereas, the intraindividual variability was 4.51mg/L. Final model then was applied to predict serum vancomycin concentrations on validation group. Predictive performance revealed a bias of -1.43mg/L (95% CI: -5.82-2.99) and a precision of 12.2mg/L (95% CI: -1.60-26.16). In conclusion, population pharmacokinetic of vancomycin in Thai adult patients was developed. The model could be used to create vancomycin dosage regimen in the type of patient similar with the present study.