Risk of Acute Kidney Injury and Clostridioides difficile Infection With Piperacillin/Tazobactam, Cefepime, and Meropenem With or Without Vancomycin

Background. Empiric antimicrobial therapy for healthcare-acquired infections often includes vancomycin plus an antipseudomonal beta-lactam (AP-BL). These agents vary in risk for adverse events, including acute kidney injury (AKI) and Clostrioides difficile infection (CDI). Studies have only examined these risks separately; thus, our objective was to evaluate AKI and CDI risks simultaneously with AP-BL in the same patient cohort. Methods. This retrospective cohort study included 789 200 Veterans Health Administration medical admissions from 1 July 2010 through 30 June 2016. The antimicrobials examined were vancomycin, cefepime, piperacillin/tazobactam, and meropenem. Cox proportional hazards regression was used to contrast risks for AKI and CDI across individual target antimicrobials and vancomycin combination therapies, including adjustment for known confounders. Results. With respect to the base rate of AKI among patients who did not receive a target antibiotic (4.6%), the adjusted hazards ratios for piperacillin/tazobactam, cefepime, and meropenem were 1.50 (95% CI: 1.43-1.54), 1.00 (.95-1.05), 0.92 (.83-1.01), respectively. Co-administration of vancomycin increased AKI rates (data not shown). Similarly, against the base rate of CDI (0.7%), these ratios were 1.21 (1.07-1.36), 1.89 (1.62-2.20), and 1.99 (1.55-2.56), respectively. Addition of vancomycin had minimal impact on CDI rates (data not shown). Conclusions. Piperacillin/tazobactam increased AKI risk, which was exacerbated by concurrent vancomycin. Cefepime and meropenem increased CDI risk relative to piperacillin/tazobactam. Clinicians should consider the risks and benefits of AP-BL when selecting empiric regimens. Further well-designed studies evaluating the global risks of AP-BL and patient specific characteristics that can guide empiric selection are needed.

Automated summary

The study found that piperacillin/tazobactam increased the risk of AKI in healthcare-acquired infection treatment, while cefepime and meropenem increased the risk of CDI relative to piperacillin/tazobactam.