Evaluation of Area Underneath the Concentration-Time Curve-Guided Vancomycin Dosing with or without Piperacillin-Tazobactam on the Incidence of Acute Kidney Injury.

ABSTRACT Objectives: Recent studies suggest that the combination of piperacillin-tazobactam (P-T) and vancomycin increases the risk for acute kidney injury (AKI). The purpose of this study was to determine if area under the concentration–time curve (AUC)-guided vancomycin dosing reduced the incidence of AKI in a sample of patients who also received P-T. Methods: This single-centre, retrospective, pre–post quasi-experimental study compared the incidence of AKI before and after a health-system-wide change from trough- to AUC-guided vancomycin dosing using two post-distribution levels. The primary outcome was AKI, defined as an increase in serum creatinine ≥0.5 mg/dL or 50% from baseline for two consecutive measurements, in patients who received vancomycin with or without concomitant P-T. Results: In total, 636 patients were included in this study (308 trough-guided, 328 AUC-guided); of these, 118 patients in each group received concomitant P-T. The primary outcome occurred in 35 (11.4%) patients in the trough-guided group and 24 (7.3%) patients in the AUC-guided group (P=0.105). There was no difference in the incidence of AKI in the population receiving concomitant P-T between dosing strategies. The incidence of AKI was significantly higher in patients who received concomitant P-T compared with patients who did not receive concomitant P-T in both the trough-guided group [21/118 (17.8%) versus 14/190 (7.4%), respectively; P=0.003] and the AUC-guided group [16/118 (13.6%) versus 8/210 (3.8%), respectively; P=0.0011]. Conclusions: The incidence of AKI did not differ significantly between trough- and AUC-guided vancomycin dosing. Caution should be taken when combining vancomycin and P-T regardless of dosing strategy. Larger studies are needed to confirm these findings.