517. Impact of Doxycycline in place of Azithromycin for Community Acquired Pneumonia on Clostridium difficile Infections
Session: Poster Abstract Session: Healthcare Epidemiology: Updates in C. difficile
Thursday, October 4, 2018
Room: S Poster Hall
  • Jamie John IDWeek Poster 2018 CDI.pdf (459.2 kB)
  • Background:

    As antimicrobial exposure represents a major risk factor in the development of Clostridium difficile infection (CDI), optimization of antimicrobial selection is critical. While a number of antibiotics have been associated with increased risk of CDI, doxycycline may be considered protective. The combination of ceftriaxone and doxycycline (CTX-D) is supported by the Infectious Diseases Society of America (IDSA) for the management of community acquired pneumonia (CAP). The primary objective of this study is to evaluate if CTX-D is associated with a reduced incidence of CDI compared to ceftriaxone and azithromycin (CTX-A) among non-intensive care unit (ICU) patients with CAP at Christiana Care Health System.


    A retrospective cohort study was conducted to evaluate patients who received CTX-D or CTX-A admitted to Christiana Care between June 1, 2015 and December 31, 2017. Non-ICU patients, aged 18 years or older, receiving at least one dose of CTX-D or CTX-A were included. The primary outcome of our study was the incidence of CDI within 30 days from initial dose of CTX-D or CTX-A. The secondary outcome was the time to onset of CDI from initial dose of CTX-D or CTX-A.


    One thousand sixty four unique patients were included in this study. Overall, 778 patients received CTX-D and 286 received CTX-A. Among patients who received CTX-D, 2 patients developed CDI, compared to 5 patients who received CTX-A (relative risk, 0.15; 95% confidence interval, 0.03-0.75; p=0.02). The mean time to onset of CDI from initiation of CTX-D was 22 days compared to 9.2 days from initiation of CTX-A.


    In this cohort of non-ICU patients with CAP, CTX-D was associated with a reduced incidence of CDI. Further studies are necessary to confirm these preliminary findings to optimize clinical practice, while minimizing potential adverse outcomes associated with antimicrobial use.

    Jamie John, PharmD, Thuy Le, PharmD, BCPS and Nicole Harrington, PharmD, BCPS, Christiana Care Health System, Newark, DE


    J. John, None

    T. Le, None

    N. Harrington, None

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