Fosfomycin Prevents Intravenous Antibiotic Therapy in Women With Recurrent Urinary Tract Infections: A Retrospective Review.

Objectives: The aim of this study was to evaluate the role of oral fosfomycin to prevent the use of intravenous (IV) antibiotic therapy in women with recurrent urinary tract infection (RUTI) complicated by antibiotic allergies and/or multidrug-resistant organisms.

Methods: After institutional review board approval, a retrospective review of women prescribed fosfomycin for RUTI at our institution was performed. Excluded were patients who did not take fosfomycin. Data collected included demographics, baseline voiding function/urological anatomic abnormalities, need for IV antibiotic therapy for RUTI, RUTI-related surgery, antibiotic allergies, and urine culture results before and after taking fosfomycin. Success was defined as no subsequent IV antibiotic use for RUTI management after fosfomycin within the study follow-up. Secondary outcomes included time to next UTI after fosfomycin, time to next extended-spectrum beta-lactamase UTI, factors predicting failure, urine culture results after fosfomycin, and need for surgical intervention.

Results: Between 2013 and 2019, 105 women met study criteria. At a median follow-up (including phone interviews) of 1.7 years (interquartile range, 0.3-5.8) after fosfomycin, the success rate was 74%. Twenty-seven patients had documented sterile urine cultures immediately after fosfomycin. Prior history of hospitalization for UTI and infection with resistant organisms were predictive of failure. After fosfomycin, 25 women underwent bladder electrofulguration, and 3 required cystectomy.

Conclusions: Fosfomycin reduced the rate of IV antibiotic therapy in the management of RUTI in women with multidrug-resistant organisms and/or antibiotic allergies. Fosfomycin was less effective in those with prior hospitalization for UTI or infection with resistant organisms.