730A Retrospective Comparison of Self – Administered Ceftriaxone vs Cefazolin for Methicillin-Susceptible Staphylococcus Aureus Bacteremia in an Outpatient Antibiotic Therapy Setting.

Background. MSSA bacteremia is a common cause of community-acquired and hospital-acquired infections with significant morbidity and mortality. Ceftriaxone is a third generation cephalosporin with activity against gram positive and gram negative aerobic bacteria including MSSA. It is well tolerated and offers significant cost reduction with its once daily dosing in the outpatient setting. Although it is not considered the antimicrobial agent of choice for MSSA infections, its pharmacokinetic profile and presumed activity against MSSA make it an option for long term antibiotic administration. There are, however, few published data documenting its efficacy in the treatment of significant MSSA bacteremia. Methods. We conducted a retrospective cohort study of patients with MSSA bacteremia at the Outpatient Parenteral Antimicrobial Therapy (OPAT) Clinic at Parkland Hospital from January 2011 to December 2013 that were treated with either self-administered cefazolin or ceftriaxone as the definitive treatment. We collected demographic, clinical outcome data, and adverse events. Successful treatment (clinical improvement, no 90 day readmission, no recurrence of bacteremia) was compared after the completion of the two antibiotics. Results. In total, 65 patients were seen at the OPAT clinic for MSSA bacteremia. 23 (35%) received cefazolin and 23 (35%) received ceftriaxone. Mean duration of treatment was 33 days. All patients received nafcillin or cefazolin in the hospital prior to initiating definitive therapy outpatient. Most common etiologies of the bacteremia included osteomyelitis (56%), skin soft tissue infection (15%), line related infection (15%), and endocarditis (13%). 90 day readmission rate was similar (3 of 23 [13% for cefazolin and 4 of 23 [17%] for ceftriaxone). Treatment success were similar after the completion of antibiotics (20 of 23 [87%] for cefazolin vs 19 of 23 [83%] for ceftriaxone). None of the patients from both group had adverse effects requiring discontinuation. Conclusion. In this comparison of ceftriaxone vs cefazolin for MSSA bacteremia, there was no difference in treatment success after completion of antibiotics. Ceftriaxone is therefore an acceptable alternative to Cefazolin for MSSA bacteremia in the outpatient setting. Disclosures. All authors: No reported disclosures.