127. Save the Beans! Acute Kidney Injury During Vancomycin and Piperacillin-Tazobactam (VP) Compared to Vancomycin and Cefepime (VC) Therapy
Session: Poster Abstract Session: Antimicrobial Stewardship: Adverse Drug Events
Thursday, October 8, 2015
Room: Poster Hall
Posters
  • Gandotra Scholarship Poster IDSA for uploading.pdf (1.8 MB)
  • Background: Vancomycin and anti-pseudomonal antibiotics such as piperacillin-tazobactam and cefepime are commonly used in hospitalized patients. Vancomycin nephrotoxicity is well recognized, with a reported incidence of ~5% when used alone. However, recent studies noted greater nephrotoxicity with VP than VC combination therapy. Since VP is the most common empiric regimen used at our hospital, we evaluated the incidence and risk factors for nephrotoxicity from VP compared to VC.

    Methods: A retrospective chart review of inpatients over age 18 receiving VP or VC for ≥48 hours was conducted at Rochester General Hospital from 1/1/14 to 8/30/14. Patients were excluded if a study antibiotic was received in the past 7 days, study antibiotics started more than 48 hours apart, undergoing dialysis, serum creatinine>1.5 times baseline or creatinine clearance <30mL/min at therapy initiation. We estimated that 43 patients were required per group for 80% power to detect a 25% difference in acute kidney injury (AKI) by AKIN criteria. Concomitant nephrotoxin use and Charlson Comorbidity Index (CCI) scores were also recorded. Χ2 tests were used to evaluate for AKI. Univariate analysis was conducted for AKI risk factors, followed by multivariate analysis.

    Results: AKI occurred in 36/111 (32%) of VP courses versus 10/66 (15%) of VC courses, p=0.011, OR 2.13. There was no difference in days of therapy, length of stay, CCI score, or median and maximal vancomycin levels between groups. Most patients were classified as AKIN stage 1 (VP 69%, VC 80%, p=0.7). AKI developed later in VC than VP (6.5 versus 3 days, p=0.028), however AKI duration was similar. Dialysis was more often needed with VP (8% vs 0%, p=0.6). More VC patients received concomitant chemotherapy (3% vs 11%, p=0.028) and acyclovir (0% vs 11%, p=0.001), while ACE/ARB therapy was more common in VP cases (35% vs 17%, p=0.008). By multivariate analysis these variables were not independently associated with AKI.

    Conclusion: The higher incidence of AKI during VP therapy corresponds to the incidence reported in prior studies. The mechanism of AKI is not known, but it is likely that the increased risk arises from the combination, since none of these antibiotics used alone have high AKI risk.  Clinicians should consider this differential risk of nephrotoxicity when initiating empiric antibiotics in hospitalized patients.

    Sheetal Gandotra, MD, Internal Medicine, Rochester General Hospital, Rochester, NY, Mindee Hite, PharmD, Department of Pharmacy, Rochester General Hospital, Rochester, NY, John Kevin Hix, MD, Department of Nephrology, Rochester General Hospital, Rochester, NY and Maryrose Laguio, MD, Infectious Disease, Rochester General Hospital, Rochester, NY

    Disclosures:

    S. Gandotra, None

    M. Hite, None

    J. K. Hix, None

    M. Laguio, None

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