Intravesical gentamicin treatment for recurrent urinary tract infections: A systematic review over the last two decades

Objectives: Recurrent urinary tract infections (rUTIs) have a significant effect on a patient's quality of life and frequent use of antibiotics increases multi-drug resistance. Previous research on intravesical antibiotics suggests that this has a local effect on bacteria with reduced systemic absorption and associated side effects. We conducted a systematic review to assess the effectiveness and adverse effects of intravesical gentamicin treatment. Methods: Systematic review of all English published articles from January 2001 to October 2021 according to the Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards. Results: A total of 139 studies were identified, 20 full-text articles were screened and 6 subsequently included totalling 166 patients. All studies reported a decrease in the mean number of urinary tract infections (UTIs) with a significant reduction (p = 0.0025 and p < 0.004) in two studies. When the number of breakthrough UTIs on prophylactic gentamicin installations was assessed, 65% (n = 86/133) remained UTI free. Throughout treatment, 99% of serum gentamicin levels were <0.3 ng/dL, and reported instances of increased creatinine were low (2%). A decrease in the growth of multi-drug-resistant bacteria was reported in two papers (p = 0.065 and p = 0.04). Conclusion: Intravesical gentamicin seems to be an effective treatment in patients with symptomatic rUTIs. The evidence suggests it also reduces UTIs caused by multi-drug-resistant bacteria with no systemic absorption and minimal renal toxicity.