Assessment of Fosfomycin for Complicated or Multidrug-Resistant Urinary Tract Infections: Patient Characteristics and Outcomes

Abstract

Background: Bacterial resistance among uropathogens is on the rise and has led to a decreased effectiveness of oral therapies. Fosfomycin tromethamine (fosfomycin) is indicated for uncomplicated urinary tract infections (UTIs) and displays in vitro activity against multidrug-resistant (MDR) isolates; however, clinical data assessing fosfomycin for the treatment of complicated or MDR UTIs are limited. Methods: We conducted a retrospective evaluation of patients who received ≥1 dose of fosfomycin between January 2009 and September 2015 for treatment of a UTI. Patients were included if they had a positive urine culture and documented signs/symptoms of a UTI. Results: Fifty-seven patients were included; 44 (77.2%) had complicated UTIs, 36 (63.2%) had MDR UTIs, and a total of 23 (40.4%) patients had a UTI that was both complicated and MDR. The majority of patients were female (66.7%) and elderly (median age, 79 years). Overall, the most common pathogens isolated were Escherichia coli (n = 28), Enterococcus spp. (n = 22), and Pseudomonas aeruginosa (n = 8). Twenty-eight patients (49.1%) were clinically evaluable; the preponderance achieved clinical success (96.4%). Fifteen out of 20 (75%) patients with repeat urine cultures had a microbiological cure. Conclusions: This retrospective study adds to the limited literature exploring alternative therapies for complicated and MDR UTIs with results providing additional evidence that fosfomycin may be an effective oral option.