Intravesical therapy for recurrent urinary tract infection: a systematic review and meta‐analysis

Objective To undertake a systematic review and meta‐analysis to evaluate the efficacy, safety, and clinical applicability of intravesical instillations for preventing recurrent urinary tract infections (rUTIs). Methods PubMed/MEDLINE, Embase, Cochrane CENTRAL, Scopus, and Web of Science were searched from January 2000 to April 2025 for randomised and observational studies of intravesical instillations in rUTI treatment. The primary outcome was UTI recurrence, expressed as incidence rate ratio (IRR) or risk ratio (RR). Random‐effects meta‐analyses were performed for three intervention families: aminoglycosides, hyaluronic acid (HA) monotherapy, and HA with chondroitin sulphate (HA + CS) combined therapy. Subgroup analyses examined population type and antibiotic used; sensitivity analyses included leave‐one‐out re‐estimation. Other agents were narratively synthesised. Results Total of 25 studies were included. Aminoglycoside instillations produced a marked reduction in recurrence (pooled IRR 0.23, 95% confidence interval [CI] 0.15–0.37; P < 0.001), with consistent benefit across neurogenic and non‐neurogenic populations and across gentamicin and amikacin. HA monotherapy was also effective (pooled RR 0.15, 95% CI 0.05–0.43; P = 0.011), although heterogeneity was high. HA + CS combined therapy showed favourable results in individual studies but an imprecise pooled effect (RR 0.41, 95% CI 0.04–4.77; P = 0.465). Narrative evidence for heparin, povidone‐iodine and fosfomycin suggested potential benefit, but methods and outcome definitions were inconsistent. Serum aminoglycoside levels were undetectable where measured, and adverse events were mild and infrequent. Conclusion Intravesical instillations appear safe and effective for preventing rUTIs in select patients. The strongest evidence supports aminoglycosides while HA offers a non‐antibiotic alternative. HA + CS requires further study. Larger, high‐quality randomised trials with standardised outcomes are needed to optimise protocols and patient selection.