Oral antibiotics for the treatment of Gram-negative bloodstream infections: A retrospective comparison of three antibiotic classes.

Objectives: Treatment of bacteraemia with oral antibiotics has the potential to reduce hospital length of stay, treatment costs and line-related complications. To date, small trials have supported the use of specific classes of antibiotics, primarily fluoroquinolones (FQs), in the treatment of Gram-negative bloodstream infections (GNBSIs). Currently, limited data exist evaluating treatment with β-lactams (BLs) or trimethoprim/sulfamethoxazole (SXT). The purpose of this study was to compare treatment of GNBSIs across three different oral antibiotic classes.

Methods: A retrospective cohort of hospitalised patients with GNBSI receiving initial intravenous (i.v.) antibiotic therapy followed by step-down oral therapy was conducted. Patients were divided into one of three oral antibiotic treatment groups: FQ; BL; or SXT. The composite primary endpoint was treatment failure, including 30-day mortality, recurrent bacteraemia or transition back to i.v. antibiotics. Additional endpoints included secondary infections and individual components within the primary endpoint. Categorical endpoints were analysed using χ test or Fisher's exact test, whilst continuous variables were assessed by one-way ANOVA.

Results: A total of 204 patients were included in the analysis. The majority of patients received a FQ (136; 66.7%), followed by a BL (46; 22.5%) and SXT (22; 10.8%). Treatment failure occurred in 15 patients (7.4%), with no statistically significant differences between groups. Likewise, individual composite outcomes and secondary outcomes demonstrated no statistically significant differences.

Conclusion: Transitioning to oral antibiotics to complete GNBSI treatment can offer many advantages. As FQ resistance increases, data supporting the use of a BL or SXT in GNBSI treatment will become essential.