Aminoglycoside versus β-lactam treatment for urosepsis-a retrospective cohort study

Aminoglycosides, once less favoured compared with β-lactams (BLs) for treating urinary tract infections (UTIs), have gained attention due to the rising prevalence of ESBL-producing Enterobacterales. However, comparative data on the efficacy and safety of aminoglycosides versus BLs are limited.

We retrospectively compared patients with Gram-negative bacteraemic UTIs, who received monotherapy with aminoglycosides or BLs for at least 3 days. The primary outcome was clinical improvement at 72 h. Secondary outcomes included clinical improvement by discharge, time to improvement, mortality, length of stay, relapse rate and kidney injury.

Out of 134 patients, 96 received BLs and 38 received aminoglycosides. BL recipients had more comorbidities, renal failure and higher clinical severity of bacteraemia. Clinical improvement for BLs versus aminoglycosides was similar at 72 h (55% versus 65.8%, P = 0.335) and by discharge (87.5% versus 94.7%, P = 0.663). A multivariate analysis accounting for baseline differences showed similar efficacy at both timepoints, with ORs for improvement for BLs versus aminoglycosides of 1.52 (95% CI 0.54-4.31). Hospital stay was 1.7 days shorter with aminoglycosides. Other secondary outcomes were not different between groups. Kidney injury was more common with aminoglycosides, but this difference was not significant and was not found when the analysis was limited to patients with a creatinine level of <1.5 mg/dL.

In this cohort of bacteraemic patients with UTI, aminoglycosides were associated with similar outcomes as BLs, with no significant risk of toxicity. Given their broad Gram-negative coverage and favourable pharmacokinetics, aminoglycosides could be reconsidered as a first-line treatment option for UTIs.