Comparison of Acute Kidney Injury During Treatment with Vancomycin in Combination with Piperacillin‐Tazobactam or Cefepime

STUDY OBJECTIVE: To evaluate the observed incidence of acute kidney injury (AKI) in adult patients receiving either piperacillin-tazobactam and vancomycin or cefepime-vancomycin for more than 48 hours. DESIGN: Retrospective matched cohort. SETTING: Large academic medical center. PATIENTS: Adult patients without preexisting renal dysfunction admitted over an 8-month time period who received either the combination of piperacillin-tazobactam and vancomycin or cefepime-vancomycin for more than 48 hours were evaluated for AKI, defined by the Acute Kidney Injury Network criteria. MEASUREMENTS AND MAIN RESULTS: A total of 224 patients receiving either antimicrobial combination were evaluated for AKI. The incidence of AKI was significantly higher in the piperacillin-tazobactam and vancomycin group (34.8%) compared with the cefepime-vancomycin group (12.5%) in the unmatched analysis (p<0.0001). After adjusting for potential sources of bias through propensity score matched pairs and conditional logistic regression, piperacillin-tazobactam and vancomycin combination therapy (p=0.003) was an independent predictor of AKI. There were no significant differences in time to AKI or hospital length of stay between groups. CONCLUSIONS: The results of this study suggest that there may be an association between piperacillin-tazobactam and vancomycin combination therapy and increased incidence of AKI.