1077. Ceftriaxone for the Treatment of Methicillin-Susceptible Staphylococcus aureus Bloodstream Infections
Session: Poster Abstract Session: Clinical Infectious Diseases: Bacteremia and Endocarditis
Friday, October 28, 2016
Room: Poster Hall
Background: Methicillin-susceptible Staphylococcus aureus (MSSA) is responsible for 45% of all S. aureus bloodstream infections (BSI). The standard of care therapy (SOCT) for MSSA BSI is an anti-staphylococcal penicillin or cefazolin. However, dosing frequencies of these agents are often infeasible, particularly outpatient. Ceftriaxone (CRO) represents a promising alternative with once-daily dosing and in vitrosusceptibility against MSSA.

Methods: This retrospective cohort conducted from Feb 2015 to Jan 2016 screened adult patients with positive blood cultures for MSSA. Inclusion criteria were definitive therapy with SOCT or CRO for ≥ 48 hours with appropriate treatment duration. Exclusion criteria were receipt of vancomycin or concomitant systemic antimicrobials with in vitro MSSA activity, polymicrobial infections, and pregnant patients. Additional data collected included demographics, source/site of infection, and treatment regimen. The primary endpoint was clinical cure, defined as normalization of white blood cell count and temperature within 7 days of the first positive blood culture and clearance of BSI within 7 days. Readmission within 60 days, length of stay, and discharge disposition were also collected.

Results: 34 patients were included: 20 SOCT and 14 CRO patients. Median (IQR) age was 48.5 (36-58); 68% were male. With the exception of diabetes (SOCT: 35%, CRO: 71%; p=0.037), comorbidities were comparable between groups. Bone/joint (27%) and skin/soft tissue (27%) were the most frequently reported source of infection; there were no differences between groups. Clinical cure was observed in 50% of patients (SOCT: 12 (60%), CRO: 5 (36%); p=0.163) despite source control (94%) and infectious diseases consultation (97%) (p=0.717). Microbiological cure (77%) and median (IQR) length of stay (12 (8-23) days) were similar between groups (p=0.228; p=0.717). Readmission rates were 24%, with 3x as many infection-related readmissions observed in the SOCT vs. CRO patients (p=0.422). Of these patients, 67% SOCT and 50% CRO had infections at the same site as their previous admission (p=0.379).

Conclusion: Ceftriaxone appears to be a viable alternative for the treatment of MSSA bloodstream infections.

Katie E. Barber, PharmD, Jamie L. Wagner, PharmD, Rachel Lowe, PharmD Candidate and Kayla R. Stover, PharmD, BCPS, University of Mississippi School of Pharmacy, Jackson, MS


K. E. Barber, Forest Laboratories: Grant Investigator , Grant recipient

J. L. Wagner, None

R. Lowe, None

K. R. Stover, Astellas Pharma: Grant Investigator , Grant recipient

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