205. Comparing Cefazolin and Nafcillin in Treatment of Methicillin-Susceptible Staphylococcus Aureus Bacteremia: A Retrospective Study in a Single Center in the South Bronx

Background Methicillin-Susceptible Staphylococcus Aureus (MSSA) bacteremia treatment includes B-lactams as first-line therapy; however, comparative effectiveness within B-lactams has not been well studied in literature. Herein, we look at definitive treatment with nafcillin or cefazolin in patients with MSSA bacteremia. Methods This retrospective study included patients admitted at Lincoln Medical Center from January 2000 to March 2019 who had a positive blood culture for MSSA and was treated with either nafcillin or cefazolin. We excluded patients who received both nafcillin and cefazolin. In addition to this, included patients had to have (1) bacteremia alone with 14 days treatment after first negative blood culture or (2) endocarditis or osteoarthritis with 6 weeks treatment after first negative blood culture. Results Of the 186 patients identified to have at least one positive culture for MSSA during the study period, only Eighty-two patients met our set criteria. Seventy of our patients were treated with nafcillin while 12 patients were treated with cefazolin. Outcome measures included duration of bacteremia (P = 0.151), ICU admissions (P = 0.542) and development of Clostridium difficile (P = 0.475). All-cause 30 day mortality and recurrent MSSA bacteremia were not different between the two treatment groups with an incidence of 17% for cefazolin vs. 21% for nafcillin (P =1) and 1% for cefazolin vs. 0% for nafcillin (P =1), respectively. Conclusion The average price of nafcillin is approximately 174 USD/day, while cefazolin is 33 USD/day. In addition to being economically practical, especially in a city hospital such as Lincoln Medical Center, cefazolin also has the benefit of only being administered every 8 hours rather than every 4 hours that nafcillin requires. This decreases the need for staff and supplies, allowing for the cefazolin regimen to be administered more easily. In this single-center study, patients who received cefazolin and nafcillin had no statistically significant difference in incidence of recurrence of bacteremia or mortality rate therefore, physicians may consider prioritizing cefazolin for treatment of MSSA bacteremia. Disclosures All authors: No reported disclosures.