Peak Measurement for Vancomycin AUC Estimation in Obese Adults Improves Precision and Lowers Bias

Vancomycin area under the curve (AUC) estimates may be skewed in obese adults due to weight-dependent pharmacokinetic parameters. We demonstrate that peak and trough measurements reduce bias and improve the precision of vancomycin AUC estimates in obese adults (n = 75) and validate this in an independent cohort (n = 31). The precision and mean percent bias of Bayesian vancomycin AUC estimates are comparable between covariate-dependent (R-2 = 0.774, 3.55%) and covariate-independent (R-2 = 0.804, 3.28%) models when peaks and troughs are measured but not when measurements are restricted to troughs only (R-2 = 0.557, 15.5%).