Comparison of Vancomycin Trough–Based and 24-Hour Area Under the Curve Over Minimum Inhibitory Concentration (AUC/MIC)–Based Therapeutic Drug Monitoring in Pediatric Patients

OBJECTIVES Vancomycin 24-hour area under the curve over minimum inhibitory concentration (AUC/MIC) monitoring has been recommended over trough-based monitoring in pediatric patients. This study compared the proportion of target attainment between vancomycin AUC/MIC and trough-based methods, and identified risk factors for subtherapeutic initial extrapolated targets. METHODS This was a retrospective, observational study conducted at KK Women’s and Children’s Hospital (KKH), Singapore. Patients aged 1 month to 18 years with stable renal function who received intravenous vancomycin between January 2014 and October 2017, with at least 2 vancomycin serum concentrations obtained after the first dose of vancomycin, were included. Using a pharmacokinetic software, namely Adult and Pediatric Kinetics (APK), initial extrapolated steady-state troughs and 24-hour AUC were determined by using a one-compartmental model. Statistical tests included Wilcoxon rank sum test, McNemar test, logistic regression, and classification and regression tree (CART) analysis. RESULTS Of the 82 pediatric patients included, a significantly larger proportion of patients achieved therapeutic targets when the AUC/MIC-based method (24, 29.3%) was used than with the trough-based method (9, 11.0%; p < 0.01). Patients with estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 or with age <13 years had an increased risk of obtaining subtherapeutic targets. However, empiric vancomycin doses of 60 mg/kg/day would be sufficient to achieve serum therapeutic targets, using the AUC/MIC-based method. CONCLUSION The AUC/MIC-based vancomycin monitoring may be preferred because a larger proportion of patients could achieve initial therapeutic targets. Future prospective studies with larger sample size will be required to determine the optimal vancomycin strategy for pediatric patients.