Ceftriaxone as an Alternative Therapy for the Treatment of Methicillin-Susceptible Staphylococcus aureus Bacteremia after Initial Clearance of Bloodstream Infection

Post-treatment outcomes of ceftriaxone versus antistaphylococcal penicillins or cefazolin for definitive therapy of methicillin-susceptible Staphylococcus aureus bacteremia

Methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia is associated with poor outcomes. Ceftriaxone offers logistical advantages over other standard therapies, though in vitro studies have questioned its efficacy and clinical studies of ceftriaxone in MSSA bacteremia are conflicting.We performed a multicenter, retrospective cohort study of adult patients who received ceftriaxone, cefazolin, or antistaphylococcal penicillins as definitive therapy for MSSA bacteremia from 2018 to 2019. Definitive therapy was defined as the antibiotic used in the outpatient setting. Patients were excluded if they received less than 7 days of outpatient therapy. Follow-up started on the date of definitive therapy completion. The primary outcome was 90-day treatment failure, defined as a composite of mortality and microbiologic recurrence. This was analyzed with multivariable Cox regression. A total of 223 patients were included, 37 (16.6%) of whom received ceftriaxone. The most common ceftriaxone dose was 2 g daily (83.8%). The most common primary site of infection was skin/soft tissue (37.2%), unknown (21.1%), and catheter-related (15.2%). Twenty-six (11.7%) developed infective endocarditis. Median total duration of treatment was 31.0 days, and median outpatient duration was 24.0 days. Twenty-six (11.7%) developed 90-day treatment failure. After adjusting for Charlson comorbidity index, duration of therapy, and use of transesophageal echocardiography, definitive treatment with ceftriaxone was associated with treatment failure (hazard ratio 2.66, 95% confidence interval 1.15-6.12; p=0.022). Among patients with MSSA bacteremia, definitive treatment with ceftriaxone was associated with a higher risk of treatment failure within 90 days as compared to cefazolin or antistaphylococcal penicillins.

Clinical Outcomes of an Innovative Cefazolin Delivery Program for MSSA Infections in OPAT

Cefazolin is a recommended treatment for methicillin-susceptible Staphylococcus aureus (MSSA) infections that has been successfully used in outpatient parenteral antibiotic therapy (OPAT) programs. The aim of this study was to assess the clinical outcomes of cefazolin delivered each day (Group 24) vs. every two days (Group 48) for MSSA infections in OPAT programs. It was a prospective observational study with retrospective analysis of a cohort of MSSA infections attended in OPAT. The primary outcome was treatment success, defined as completing the antimicrobial regimen without death, treatment discontinuation, or readmission during treatment and follow-up. A univariate and multivariate logistic regression model was built. A two-sided p < 0.05 was considered statistically significant. Of the 149 MSSA infections treated with cefazolin 2 g/8 h in OPATs, 94 and 55 patients were included in the delivery Group 24 and Group 48, respectively. Treatment failure and unplanned readmission rates were similar in both groups (11.7% vs. 7.3% p = 0.752 and 8.5% vs. 5.5% p = 0.491). There was a significant increase in vascular access complications in Group 24 (33.0%) with respect to Group 48 (7.3%) (p < 0.001). Treating uncomplicated MSSA infection with cefazolin home-delivered every two days through an OPAT program is not associated with an increased risk of treatment failure and entails a significant reduction in resource consumption compared to daily delivery.

Effectiveness and Safety of Ceftriaxone Compared to Standard of Care for Treatment of Bloodstream Infections Due to Methicillin-Susceptible Staphylococcus aureus: A Systematic Review and Meta-Analysis

(1) Background: Ceftriaxone is a potential alternative for the treatment of methicillin-susceptible Staphylococcus aureus (MSSA) bloodstream infections (BSIs) in acute care and outpatient parenteral antimicrobial therapy (OPAT) settings. We evaluated the effectiveness and safety of ceftriaxone for the treatment of MSSA BSIs. (2) Method: We searched PubMed, Embase, and Cochrane Library from their inception to October 30th 2021. Our outcomes included clinical cure, microbiological cure, 30- and 90-day mortality, 90-day hospital readmission, and adverse drug reactions (ADRs). We compared ceftriaxone against standard of care (SOC) therapy. We used the random-effects model for the meta-analysis, and our estimated effects were reported as odds ratios (ORs) with 95% confidence intervals (CI). (3) Results: Twelve retrospective cohort studies were included, comprising 1037 patients in the ceftriaxone arms and 2088 patients in the SOC arms. The clinical cure rate of the ceftriaxone regimen was not statistically different from SOC: OR 0.65 (95% CI: 0.29-1.45). Ceftriaxone was also not statistically different from SOC in microbiological cure: OR 1.48 (95% CI: 0.29-7.51); 30-day mortality: OR 0.79 (95% CI: 0.14-4.65); 90-day mortality: OR 0.82 (95% CI: 0.38-1.80); 90-day hospital readmission: OR 1.20 (95% CI: 0.92-1.56); and ADRs: OR 0.92 (95% CI: 0.39-2.18). (4) Conclusion: Ceftriaxone could provide an alternative for the treatment of MSSA BSIs in acute care and OPAT settings (except in patients whose BSIs were due to infective endocarditis).