Antimicrob Agents Chemother. 2020 Aug 24:AAC.01515-20. doi: 10.1128/AAC.01515-20. Online ahead of print.
Fluoroquinolones (FQs) are often preferred as oral step-down therapy for bloodstream infections (BSIs) due to favorable pharmacokinetic parameters; however, they are also associated with serious adverse events. The objective of this study was to compare clinical outcomes for patients who received an oral FQ versus an oral beta-lactam (BL) as step-down therapy for uncomplicated streptococcal BSIs.This multi-center, retrospective cohort study analyzed adult patients who completed therapy with an oral FQ or BL with at least one blood culture positive for a Streptococcus species from January 1, 2014 to June 30, 2019. The primary outcome was clinical success, defined as lack of all-cause mortality, recurrent BSI with the same organism, and infection-related readmission at 90 days. A multivariable logistic regression model for predictors of clinical failure was conducted.A total of 220 patients were included, with 87 (40%) receiving a FQ and 133 (60%) receiving a BL. Step-down therapy with an oral BL was non-inferior to an oral FQ (93.2% vs. 92.0%; mean difference 1.2%, 90% CI -5.2 to 7.8). No differences were seen in 90-day mortality, 90-day recurrent BSI, 90-day infection-related readmission, or 90-day incidence of C. difficile-associated diarrhea. Predictors of clinical failure included: oral step-down transition before day three (OR = 5.18, 95% CI 1.21, 22.16) and low dose oral-step down therapy (OR = 2.74, 95% CI 0.95, 7.90).Our results suggest that oral step-down therapy for uncomplicated streptococcal BSI with a BL is non-inferior to a FQ.