1073. Safety and Economic Benefit of Cefazolin versus Nafcillin for Methicillin Sensitive Staphylococcus aureus (MSSA) Bloodstream Infections (BSI)
Session: Poster Abstract Session: Clinical Infectious Diseases: Bacteremia and Endocarditis
Friday, October 28, 2016
Room: Poster Hall
Posters
  • MSSA Naf vs Cef 10.17.16.pdf (280.7 kB)
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    Background: Cefazolin may be preferred to anti-staphylococcal penicillins in the management of MSSA BSI because of similar effectiveness and lower drug acquisition cost. In addition, acute kidney injury (AKI) is more frequent following treatment with nafcillin than with cefazolin. The objective of this study was to evaluate the safety and economic impact of using cefazolin vs nafcillin in patients with MSSA BSI.

    Methods: This retrospective cohort was IRB approved at a four hospital health system.  Included patients ≥ 18 yr with MSSA BSI from Nov 2013 to Oct 2015 receiving cefazolin or nafcillin ≥72 hours without pre-existing renal dysfunction. Safety outcome: incidence of AKI defined as an increase in SCr from baseline >50% or ≥ 0.3 mg/dL assessed via blinded adjudication. Secondary outcomes include incidence of additional adverse effects and clinical cure defined as survival at 30 days, no reoccurrence within 60 days, and microbiologic success. Cost outcomes: Length of stay (LOS) total and ICU, drug acquisition cost, estimated cost of hospital stay. Decision analysis was used to assess most cost-effective treatment from the institutional perspective.

    Results: 157 patients included, 82 nafcillin, 75 cefazolin. The incidence of AKI was 27/82 (33%) vs 10/75 (13%) (P= 0.007), in the nafcillin and cefazolin arms respectively. In multivariate logistic regression, nafcillin was an independent predictor of AKI (adj odds ratio [OR]= 2.74; 95% [CI], 1.1 to 6.6) after adjusting for endocarditis and stay in an intensive care unit.  Cost comparisons are presented in Table 1. AKI increased LOS and cost among patients treated with nafcillin. Incremental cost effectiveness ratio could not be calculated as cefazolin was dominant.

    Conclusion: Nafcillin treatment is associated with higher incidence of nephrotoxicity than cefazolin, contributing to increased cost. Preferential use of cefazolin is a cost-effective strategy for MSSA BSI.

     

    Table 1.

    AKI Probability

    Clinical Cure Probability

    LOS (days)

    Drug Acquisition Cost ($)

    Hospital Cost ($)

    Overall Cost/Effectiveness

    Cefazolin

         AKI

    0.13

    0.93

    13

    75

    15,642

    16,059 / 0.96

         No AKI

    0.87

    0.96

    10

    57

    16,121

    Nafcillin

         AKI

    0.32

    0.68

    14

    2,278

    37,158

    28,196 / 0.83

         No AKI

    0.68

    0.90

    10

    1,647

    23,978

     

    Lauren K Flynt, PharmD1, Rachel M Kenney, PharmD1 and Susan L Davis, PharmD2, (1)Pharmacy, Henry Ford Hospital, Detroit, MI, (2)Wayne State University College of Pharmacy, Detroit, MI

    Disclosures:

    L. K. Flynt, None

    R. M. Kenney, None

    S. L. Davis, None

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