Optimizing outcomes using vancomycin therapeutic drug monitoring in patients with MRSA bacteremia: trough concentrations or area under the curve?

Abstract Background Vancomycin therapeutic drug monitoring is routinely performed but the specific measure used in practice is variable. Objective To evaluate the relationship between the first measured vancomycin trough, area-under-the-curve (AUC), and failure in patients with MRSA bacteremia. Methods This retrospective, cohort study included adult non-neutropenic patients with MRSA bacteremia who received vancomycin. The primary outcome was treatment failure. Initial trough and AUC values were compared between the failure and success groups. Classification and regression tree analysis was used to identify thresholds associated with failure. Multivariate analysis was performed to control for identified confounders. Results There were 89 patients. Failure occurred in 23 (26%). Trough and AUC values associated with failure were Conclusion Failure was more common with troughs