Background and Objective: Recurrent urinary tract infections (UTIs) in children may cause renal scarring and long-term complications. This study compared the efficacy and safety of cranberry extract, nitrofurantoin, and placebo for preventing recurrent UTIs.
Methods: This randomized, double-blind, placebo-controlled trial was conducted in Sabzevar, Iran, from April 2020 to March 2022. Children aged 2–18 years with at least two UTIs in the preceding year and no urological abnormalities were randomized to cranberry extract (36 mg/day proanthocyanidins), nitrofurantoin (1–2 mg/kg/day), or placebo. Participants were followed for 12 months. The primary outcome was symptomatic, culture-confirmed UTI recurrence (≥10⁵ CFU/mL). Secondary outcomes included adverse events, antimicrobial resistance, and adherence. Analyses followed the intention-to-treat principle.
Findings: Among 200 children (mean age, 7.8 ± 4.2 years; 72% female), recurrence rates were 25% with cranberry (HR, 0.55; 95% CI, 0.35–0.87; p = 0.01), 20% with nitrofurantoin (HR, 0.40; 95% CI, 0.25–0.65; p < 0.001), and 45% with placebo. Gastrointestinal adverse events were less frequent with cranberry than nitrofurantoin (12% vs. 35%; p < 0.01). Nitrofurantoin-resistant Escherichia coli accounted for 8% and 30% of UTIs in the cranberry and nitrofurantoin groups, respectively (p = 0.002). Adherence was 85–90%.
Conclusion: Cranberry extract reduced UTI recurrence versus placebo and was associated with fewer gastrointestinal adverse events than nitrofurantoin, suggesting a potential non-antibiotic prophylactic option for children.