Evaluating the Safety of Trough Versus Area Under the Curve (AUC)-Based Dosing Method of Vancomycin With Concomitant Piperacillin-Tazobactam

Background: Vancomycin and piperacillin-tazobactam (VPT) is a common antibiotic combination used in hospitals, and there has been increasing data indicating that the combination is associated with increased rates of acute kidney injury (AKI). It is unclear if the dosing method of vancomycin would mitigate the risk of AKI seen with VPT. Objective: To observe and compare incidence of AKI in patients on VPT when using the trough-based dosing method versus the area-under-the-curve (AUC)-based dosing method. Methods: This was a multi-center, retrospective, observational study at 3 community hospitals. Adults receiving at least 48 hours of VPT were included. Patients with severe renal dysfunction, pregnant patients, prisoners, and patients with central nervous system infections, or malignancy were excluded. The primary outcome was incidence of AKI as defined by the Infectious Disease Society of America (IDSA) criteria. Results: A total of 300 patients were included in the study; 150 patients in both the trough and AUC groups. A total of 23 patients (15%) in the trough group and 17 patients (11%) in the AUC group met the primary outcome (odds ratio [OR]: 0.7058, 95% confidence interval [CI]: [0.3603, 1.3826], P = .3098). Conclusion and Relevance: The incidence of AKI was lower in the AUC group compared with the trough group; however, this was not significant. The results of our study suggest that there is no difference between incidence of AKI when using trough- or AUC-based dosing in those receiving VPT. Because of the small sample size and retrospective nature of the study, more data are needed.