Comparative incidence of acute kidney injury in patients on vancomycin therapy in combination with cefepime, piperacillin-tazobactam or meropenem

Recent studies have shown that the incidence of nephrotoxicity increases when vancomycin is combined with a beta-lactam antibiotic. The objective of this study was to compare the incidence of acute kidney injury (AKI) in adult patients who received vancomycin with either piperacillin-tazobactam (VPT), cefepime (VC), or meropenem (VM). This was a single center retrospective chart review. Patients were included if they were 18 years or older, received 48 hours of combination therapy and antibiotics were started within 24 hours of each other. Exclusion criteria were receiving more than one combination of antibiotics, serum creatinine > 1.2 mg/dL, AKI at the time of inclusion, or any form of renal replacement therapy. Two hundred patients met inclusion criteria. A total of 27 (13%) patients experienced AKI. The incidence of AKI was 21.6%, 9%, and 7.4% in the VPT, VC and VM groups, respectively. A patient who received VPT was 5 times more likely to develop AKI when compared to a patient who received VC (adjusted OR 5.09 95% CI (1.51-17.08), p = 0.008) and 7 times more likely to develop AKI when compared to VM (adjusted OR 7.03 95% CI (1.97-28.08), p = 0.002). This study found a statistically significant difference in the incidence of AKI in patient receiving VPT when compared to VC or VM. This finding supports the need for careful monitoring of renal function in patients receiving VPT therapy and routine evaluation for de-escalation of antimicrobial therapy.