Use of Fluoroquinolones or Sulfamethoxazole-Trimethoprim Compared to Β-Lactams for Oral Step-Down Therapy in Hospitalized Patients With Uncomplicated Enterobacterales Bacteremia

Abstract

Background

Antibiotic therapy for uncomplicated Enterobacterales bacteremia from a urinary source has traditionally consisted of fluoroquinolones (FQs) and sulfamethoxazole-trimethoprim (SXT). However, adverse events associated with FQs and emerging antimicrobial resistance have led to alternative agents, specifically oral Β-lactams (OBLs), being utilized despite concern of subtherapeutic serum concentrations related to their low relative bioavailability.

Objective

To compare efficacy of antibiotic therapies with bioavailability differences in patients with uncomplicated bacteremia from a urinary source.

Methods

This was a retrospective study comparing clinical efficacy in hospitalized adult patients receiving OBL or FQ/SXT. Patients were required to receive at least 48 hours of appropriate intravenous antibiotic therapy and at least one dose of oral therapy. The primary outcome was all-cause hospital readmission within 30 days of discharge. Secondary outcomes included readmission with recurrent infectious etiology and readmission due to Clostridioides difficile infection.

Results

Of 210 eligible patients, 91 received FQ/SXT and 119 received OBL. There was no difference between the groups in all-cause hospital readmission (FQ/SXT: 16.5%; OBL: 14.3%) (P = 0.660 [95% confidence interval, CI = −0.076, 0.120]) or readmission with recurrent bacteremia (FQ/SXT: 0%; OBL: 3.4%) (P = 0.135). There was a significant difference in repeat hospital admission with recurrent urinary tract infection (UTI) (FQ/SXT: 0%, OBL: 5.0%) (P = 0.037).

Conclusion and Relevance

OBLs appear to be non-inferior to FQ/SXT in the rate of all-cause hospital readmission within 30 days. However, OBLs may be associated with increased readmissions with recurrent UTI.