Efficacy and safety of an ultra-low-dose 0.005 % estriol vaginal gel in the prevention of urinary tract infections in postmenopausal women with genitourinary syndrome of menopause: A randomized double-blind placebo-controlled trial

•Urinary tract infections are very prevalent among postmenopausal women.•53% of women aged 55 reported a recurrence within a year in primary care.•Overuse of antibiotics increases antimicrobial resistance, threatening public health.•0.005% estriol gel lowers urinary infection rates in postmenopausal women.•Ultra-low-dose estriol vaginal gel could be an alternative form of antibiotic prophylaxis. This study evaluated the efficacy of an ultra-low-dose 0.005 % estriol vaginal gel in the prevention of urinary tract infections in postmenopausal women with genitourinary syndrome of menopause. Randomized, double-blind, placebo-controlled, multicenter clinical trial conducted across 28 Spanish sites involving specialists in gynecology, urology, and primary care. A total of 108 postmenopausal women were randomly assigned in a 1:1 ratio to receive 1 g of vaginal gel with 50 micrograms of estriol or an identical moisturizing vaginal gel without estriol. The primary outcome was the number of episodes of urinary tract infection by the end of the 24-week treatment. Secondary measures encompassed percentage of patients without recurrence, time to first recurrence, use of antibiotic treatment, vaginal pH, safety, and tolerability, among others. The incidence rate of urinary tract infections (new cases per 100 women-year) was 26 % lower in the group that received estriol vs. the group that received placebo (32.34 vs. 43.76 (RR = 0.74) p