Fluoroquinolone versus Beta-Lactam Oral Step-Down Therapy for Uncomplicated Streptococcal Bloodstream Infections

Abstract

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.

Evaluation of step-down oral antibiotic therapy for uncomplicated streptococcal bloodstream infections on clinical outcomes

“…From a pharmacokinetic/pharmacodynamic standpoint, Streptococcus spp is unique with lower minimum inhibitory concentrations (MICs) compared with other organisms, which makes the oral option very attractive, even for some of the beta-lactam agents that may not have high bioavailability. Recent studies have evaluated oral antibiotics of high (fluoroquinolones, clindamycin, and doxycycline) versus low bioavailability (beta-lactam) 28 and fluoroquinolones versus oral beta-lactams 29 and found comparable outcomes in the beta-lactam group. In our study, beta-lactam agents were the second most commonly utilized oral agents (32%) after fluoroquinolones (40%), although we could not make meaningful comparisons based on oral antibiotic choice on its effect on outcomes due to the small sample size.…”

Snapshots From ID Week 2021

“…There is ongoing interest in the duration of treatment for gram-negative bacteremia. A recent randomized controlled trial comparing 7 versus 14 days of antibiotics for treatment of uncomplicated gram negative bacteremia found 7 days of therapy to be noninferior to 14 days of therapy 1 . Of the isolates included in this trial, only 8.6% were PA, and the optimal duration of treatment remains unknown.…”

“…There is literature specifically comparing oral agents. A brief review of the literature revealed a previous study comparing two oral antimicrobial agents, fluoroquinolones and β-lactams, for treatment of uncomplicated streptococcal bloodstream infections with results suggesting that oral step-down therapy for uncomplicated streptococcal bloodstream infection with a βlactams is non-inferior to a fluoroquinolone 1 . In conclusion, oral step-down therapy appears to be a reasonable and cost-savings option for uncomplicated non-Staphylococcal Gram-positive bacteremia.…”

Significant Publications on Infectious Diseases Pharmacotherapy in 2020

“…Step-Down Therapy for Uncomplicated Streptococcal Bloodstream Infections 17 Transitioning from intravenous (IV) to oral antibiotics in clinically stable patients with bacteremia has become an increasingly common practice. Generally, fluoroquinolones (FQs) are chosen over β-lactams due to favorable pharmacokinetic parameters including improved bioavailability.…”