1855. Impact of Penicillin Allergy on Empiric Carbapenem Use in Patients with Community-Onset Gram-Negative Bloodstream Infections
Session: Poster Abstract Session: Antibiotic Stewardship: Beta Lactam Allergy
Saturday, October 29, 2016
Room: Poster Hall
  • Acker_IDWeek_Poster_2016.09.21_FINAL.pdf (1.5 MB)
  • Background: Penicillin is the most commonly reported medication allergy. It often results in broader empiric antibiotic selection. The primary objective of this study is to evaluate carbapenem use as empiric therapy for community-onset gram-negative (GN) bloodstream infections (BSI) in patients with penicillin allergy (PA) versus no penicillin allergy (NPA). Secondary endpoints included impact of antimicrobial stewardship and support team (ASST) interventions on carbapenem use and on time to carbapenem de-escalation in the PA group.

    Methods: This single healthcare system, retrospective, observational, matched cohort study evaluated adults hospitalized with GN BSI from January 1, 2010 to June 30, 2015. All patients with PA were enrolled and matched with control patients with NPA in a 1:1 fashion based on: age ±10 years, sex, site of acquisition (community-acquired [CA], vs. healthcare-associated), and pre- vs. post- ASST interventions (beginning January 1, 2014). Multivariable logistic regression was used to evaluate the impact of PA and ASST interventions on empiric carbapenem use.

    Results: A total of 280 patients were enrolled. Overall, the mean age was 71 years, 208 (74%) were women, 142 (51%) had CA BSI, and 64 (23%) were in the post-ASST intervention period. Empiric carbapenem use was greater in the PA vs. NPA groups (27% vs. 12%). After adjustment for covariates, including baseline differences in race and indwelling urinary catheters, PA remained independently associated with empiric carbapenem use (aOR 3.98, 95% CI 1.98-8.45, p<0.001). Other predictors of empiric carbapenems included male sex (aOR 2.18, 95% CI 1.08-4.36), Bloodstream Infection Mortality Risk Score (aOR 1.19 per point, 95% CI 1.08-1.32), and prior beta-lactam use within 90 days (aOR 2.72, 95% CI 1.07-6.64). ASST interventions were associated with reduction in empiric carbapenem use (aOR 0.41, 95% CI 0.16-0.40). Time to carbapenem de-escalation in the PA group was also significantly shorter in the post- vs. pre-ASST intervention period (2.0 vs. 4.2 days, p<0.001).

    Conclusion: Penicillin allergy is an independent risk factor for empiric carbapenem use for community-onset GN BSI. ASST interventions successfully reduced carbapenem utilization.

    Emily Acker, PharmD1, Majdi Al-Hasan, MBBS2, Joseph Kohn, PharmD, BCPS1, P. Brandon Bookstaver, PharmD, FCCP, BCPS, AAHIVP3, Casey Troficanto, PharmD, BCPS4 and Julie Ann Justo, PharmD, MS, BCPS-AQ ID3, (1)Palmetto Health Richland, Columbia, SC, (2)Department of Medicine, Division of Infectious Diseases, University of South Carolina School of Medicine, Columbia, SC, (3)Department of Clinical Pharmacy and Outcomes Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, SC, (4)Palmetto Health Baptist, Columbia, SC


    E. Acker, None

    M. Al-Hasan, None

    J. Kohn, None

    P. B. Bookstaver, Allergan Pharmaceuticals: Scientific Advisor , Research grant

    C. Troficanto, None

    J. A. Justo, None

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