Safety and Efficacy of Intravesical Gentamicin for Recurrent Urinary Tract Infections and/or Catheter Blockages.

AIMS: To assess the safety and efficacy of intravesical gentamicin in patients with recurrent urinary tract infections (UTI) and/or catheter blockages.

METHODS

This prospective, single-center study enrolled adult patients with recurrent UTIs and/or catheter blockages who had been prescribed intravesical gentamicin (once-daily, 30-60 mL, 0.48 mg/mL, held 60 min) from June 1, 2024, to April 1, 2025. Eligible patients had received ≥ 14 days' intravesical gentamicin. Primary outcomes were, for patients with recurrent UTIs, subjective (patient-reported) and objective (positive culture with symptoms) rates of UTI per 12-month-equivalent, before versus during treatment.

RESULTS

Fifty-five patients were prescribed intravesical gentamicin, of whom 42 were eligible. Median age was 58 years, and 26 patients (62%) were female. Thirty-six patients (86%) had neurogenic bladder, and 38 (90%) had pre-existing catheter use (suprapubic: 17; intermittent: 15; indwelling urethral: six). Median follow-up was 6 months. Compared with pre-treatment, patients experienced significantly fewer subjective (median 6.5 vs. 0; p < 0.00001) and objective (median 5.5 vs. 0; p < 0.00001) UTIs per 12-month-equivalent. Regarding secondary outcomes, for patients with recurrent UTIs, gentamicin was associated with decreased rates of UTI-related emergency department presentations per 12-month-equivalent (median 1 vs. 0; p = 0.005) and decreased proportion of patients with ≥ 1 multi-drug-resistant UTI (70% vs. 23%; p = 0.00002). Median ease-of-use was 4/5, and likelihood-to-recommend was 5/5. Complications were reported by 11 patients (26%), all Clavien-Dindo Grade I. Of patients with prior catheter blockages, 47% reported decreased catheter blockages, although duration between catheter changes was unchanged (median 28 vs. 28 days; p = 0.53).

CONCLUSIONS

Intravesical gentamicin appears safe and effective prophylaxis for recurrent UTIs and/or catheter blockages.

TRIAL REGISTRATION: This study has been registered with the Australian New Zealand Clinical Trials Registry, submission 389972.