A Comparative Study on Predicting %T>MIC Imipenem based on Therapeutic Drug Monitoring Results in Critically Care Patients / 中国药学杂志

ABSTRACT

OBJECTIVE: To compare and evaluate different methods of estimating %T>MIC based on drug concentration monitoring data, and clarify the implementation plan and treatment objectives of therapeutic drug monitoring. METHODS: The plasma drug concentrations of 25 patients with severe infections were collected at multiple time points after imipenem reached steady state. A population pharmacokinetic model was established by NONMEM method. The plasma drug concentrations were estimated by Bayesian feedback method at 6 and 8 h after imipenem administration. Meanwhile, the established calculation model of %T>MIC combined with the same drug concentrations was used to estimate the %T>MIC. The results of these two methods were compared with the true value of %T>MIC. RESULTS: The established population pharmacokinetic model could fit the data well. The covariate serum creatinine (CR) had a significant effect on the apparent distribution volume (Vc) of central ventricle. The final model was Vc=18.8×(CR/70.9)ΘCR_VC. When MIC=2, the results of Bayesian method and %T>MIC calculation model method showed 76.9% and 84.6% deviation within±10% of the true values, respectively. CONCLUSION: The two methods had good predictive accuracy when the MIC breakpoint was less than 2, but they decreased with the increase of MIC. Different therapeutic drug monitoring schemes should be considered for different levels of MIC.