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.