Does Vancomycin plus Piperacillin/Tazobactam Equal More Kidney Injury?

Evidence suggests that the combination of vancomycin and piperacillin/tazobactam (VPT) results in an increased risk for acute kidney injury (AKI) above that associated with vancomycin alone. However, debate about the association persists. Two recent analyses explored this issue.

Collaborators at a tertiary care system in Michigan conducted a retrospective study of 279 patients who received VPT matched 1:1 to a cohort prescribed vancomycin and cefepime. VPT was associated with a significantly increased risk for AKI according to three criteria used to define kidney injury: the RIFLE (Risk, Injury, Failure, Loss, End Stage Renal Disease) criteria, the AKIN (Acute Kidney Injury Network) criteria, and the vancomycin consensus guidelines (for all three, P<0.0001). Moreover, the onset of AKI was significantly more rapid in the VPT group and was not associated with vancomycin trough level in this group.

Separately, researchers from the University of Arkansas performed a meta-analysis on 14 studies gleaned from online databases. Overall, VPT was associated with a more than threefold increased risk for AKI compared with vancomycin alone or in combination with another β-lactam antibiotic (P<0.001).