Streamlining to Oral β-Lactam Versus Fluoroquinolone as Definitive Therapy for Enterobacteriaceae Bacteremia

Abstract

Background Oral treatment strategies for Enterobacteriaceae bacteremia (EB) are controversial. Fluoroquinolones (FQs) may be preferred for their high bioavailability, but β-lactams (BLs) should be explored as an additional option for EB treatment because of concerns of FQ resistance and adverse effects. Methods This retrospective study compared clinical characteristics and outcomes in patients with EB treated with oral BL versus FQ between January 2013 and July 2017. Adult patients with their first incidence of EB and transitioned from intravenous antibiotics to either study antibiotic class were included. The primary outcome assessed a composite of recurrence, superinfection, Clostridioides difficile colitis, emergence of multidrug-resistant organisms, infection-related readmission, and all-cause mortality within 90 days of EB treatment. Results A total of 173 patients were included (BL, n = 59; FQ, n = 114). The median age was 70 years, Pitt bacteremia score was 2 (range = 0–7), and Charlson Comorbidity Index was 5 (0–12). Urinary source of infection was most common (57%). Most oral BL courses used cefpodoxime (63%). Of note among baseline differences between groups, more patients receiving FQ versus BL had a presence of abscess (11% vs 0%, P = 0.01). The primary composite outcome occurred in 15 patients (25%) receiving BL and 28 patients (25%) on FQ (P = 0.901). Multivariate analysis identified urological complications, bacteremia onset in the intensive care unit, and the Charlson Comorbidity Index as independent predictors of the primary outcome. Conclusions Clinical outcomes were similar between those treated with oral BL compared with FQ. Oral BL may be considered for definitive treatment of EB.