Methenamine Hippurate versus Low-Dose Nitrofurantoin for Recurrent Urinary Tract Infection Prophylaxis in Women

INTRODUCTION: Recurrent urinary tract infections (rUTIs) are prevalent among women and substantially impair quality of life, underscoring the need for effective and safe preventive treatments. This study evaluated the efficacy, safety, and bacterial resistance rates of methenamine hippurate (MH) versus low-dose nitrofurantoin (NFT) for rUTI prevention in women. METHODS: We conducted a retrospective propensity score-matched cohort study involving female rUTI patients from our urology clinic between June 2021 and February 2024. After 1:1 matching, 50 patients each constituted the MH group and the low-dose NFT group. The treatment and follow-up period was 12 months, with assessments at 3, 6, and 12 months. A non-inferiority margin of Δ = 0.5 episodes per person-year was defined. The primary endpoint was the 12-month symptomatic UTI recurrence rate. Secondary outcomes included urine culture positivity, pathogen profile, antibiotic resistance, asymptomatic bacteriuria, IPSS, SF-36, direct costs, compliance, and adverse events. RESULTS: After propensity score matching, baseline characteristics were balanced. The 12-month recurrence rates were 18.00% for MH and 20.00% for NFT, confirming non-inferiority (p = 0.765). Urine culture positivity and pathogen profiles did not differ significantly. MH showed no detectable resistance versus 28.57% in NFT (p = 0.022) and lower asymptomatic bacteriuria (8.00% vs. 22.00%; p = 0.037). Compliance was similar. MH resulted in significantly improved IPSS and SF-36 scores (p < 0.001). Although drug costs were higher with MH, total management costs were lower (p < 0.001), with fewer adverse events (p < 0.05). CONCLUSION: MH demonstrates non-inferiority to low-dose NFT for preventing rUTIs in women, with reduced resistance, adverse events, and asymptomatic bacteriuria. Despite higher drug cost, its superior long-term benefit supports its use as an alternative in NFT-intolerant or high-risk patients.