Comparison of Oral and Intravenous Definitive Antibiotic Therapy for Beta-Hemolytic Streptococcus Species Bloodstream Infections from Soft Tissue Sources: a Propensity Score-Matched Analysis

Continued Intravenous Versus First Week Transition to Oral Antibiotic Therapy in Bloodstream Infections: A Systematic Review and Meta-Analysis

Bloodstream infections (BSIs) are a major public health concern worldwide, requiring prompt and effective antibiotic therapy. Traditionally, intravenous (IV) antibiotics have been preferred for their rapid action and consistent absorption. However, interest is growing in transitioning to oral (PO) antibiotics when suitable, due to similar pharmacokinetics, improved patient outcomes, and reduced healthcare costs. This meta-analysis aims to evaluate the clinical effectiveness of switching from IV to PO antibiotics for both gram-negative and gram-positive BSIs. Scopus, Embase, and PubMed databases were comprehensively searched until March 2023. The review included randomized controlled trials and cohort studies comparing continued IV therapy with early transition from IV to PO antibiotics within the first week of admission. Inclusion criteria encompassed studies involving adult patients (≥18 years) and reporting specific outcomes such as treatment success, mortality, and hospital readmissions. Meta-analysis of 17 studies comprising 11,245 patients demonstrated higher treatment success rates overall (OR: 1.40, P=0.04), particularly in gram-negative infections (OR: 1.42, P=0.05). However, this effect was not statistically significant in the gram-positive subgroup (OR: 1.41, P=0.036). Oral switch significantly reduced all-cause mortality overall (OR: 0.35, P=0.003), especially in gram-negative infections (OR: 0.22, P=0.008), but not significantly in gram-positive infections (OR: 0.60, P=0.09). Both gram-negative and gram-positive infections benefited from shorter hospital stays (P<0.0001), despite significant heterogeneity. Hospital readmission rates did not significantly differ between IV and oral switch groups (P=0.53). Our meta-analysis suggests potential benefits of early transition from IV to PO antibiotics for BSIs, including improved treatment outcomes and shorter hospital stays without an increased risk of readmission. However, these findings are subject to selection bias, and further standardized randomized trials are essential to validate these results.

Oral Antibiotics for Bacteremia and Infective Endocarditis: Current Evidence and Future Perspectives

Bacteremia and endocarditis are two clinical syndromes that, for decades, were managed exclusively with parenteral antimicrobials, irrespective of a given patient's clinical condition, causative pathogen, or its antibiotic susceptibility profile. This clinical approach, however, was based on low-quality data and outdated expert opinions. When a patient's condition has improved, gastrointestinal absorption is not compromised, and an oral antibiotic regimen reaching adequate serum concentrations is available, a switch to oral antibacterials can be applied. Although available evidence has reduced the timing of the oral switch in bacteremia to three days/until clinical improvement, there are only scarce data regarding less than 10-day intravenous antibiotic therapy in endocarditis. Many standard or studied oral antimicrobial dosages are smaller than the approved doses for parenteral administration, which is a risk factor for treatment failure; in addition, the gastrointestinal barrier may affect drug bioavailability, especially when the causative pathogen has a minimum inhibitory concentration that is close to the susceptibility breakpoint. A considerable number of patients infected by such near-breakpoint strains may not be potential candidates for oral step-down therapy to non-highly bioavailable antibiotics like beta-lactams; different breakpoints should be determined for this setting. This review will focus on summarizing findings about pathogen-specific tailoring of oral step-down therapy for bacteremia and endocarditis, but will also present laboratory and clinical data about antibiotics such as beta-lactams, linezolid, and fosfomycin that should be studied more in order to elucidate their role and optimal dosage in this context.

Intravenous versus Partial Oral Antibiotic Therapy in the Treatment of Uncomplicated Bloodstream Infection Due to Streptococcus Species

This retrospective cohort study examines effectiveness of partial oral antibiotic regimens in uncomplicated bloodstream infections (BSIs) due to Streptococcus species compared to standard intravenous therapy. Adult patients with uncomplicated streptococcal BSIs from April 2016 to June 2020 in seven hospitals in South Carolina, USA, were evaluated. Multivariate Cox proportional hazards regression was used to examine the time to treatment failure within 90 days of a BSI after adjustment for the propensity to receive partial oral therapy. Multivariate linear regression was used to examine the hospital length of stay (HLOS). Among the 222 patients included, 99 received standard intravenous antibiotics and 123 received partial oral therapy. Of the standard intravenous therapy group, 46/99 (46.5%) required outpatient parenteral antibiotic therapy (OPAT). There was no difference in the risk of treatment failure between partial oral and standard intravenous therapy (hazards ratio 0.53, 95% CI 0.18, 1.60; p = 0.25). Partial oral therapy was independently associated with a shorter HLOS after adjustments for the propensity to receive partial oral therapy and other potential confounders (-2.23 days, 95% CI -3.53, -0.94; p < 0.001). Transitioning patients to oral antibiotics may be a reasonable strategy in the management of uncomplicated streptococcal BSIs. Partial oral therapy does not seem to have a higher risk of treatment failure and may spare patients from prolonged hospitalizations and OPAT complications.