2242. Nitrofurantoin Use and Resistance in Urinary Tract Infections Across a Large, Integrated Health System

Abstract

Abstract Background Nitrofurantoin is a preferred empiric antibiotic for the treatment of acute cystitis; however, there are limited data on nitrofurantoin utilization patterns and bacterial resistance in the outpatient setting. The objectives of this study were to describe nitrofurantoin use in an integrated health system and evaluate nitrofurantoin resistance. Methods A retrospective review of patients prescribed nitrofurantoin at Denver Health from January 1, 2017 to December 31, 2021 in 9 community health centers, 2 urgent cares, and the emergency department was completed. Patients were included if they received nitrofurantoin within 72 hours of a positive urine culture, defined as > 100,000 cfu/mL of a single organism (Escherichia coli, Enterobacter cloacae, Enterobacter aerogenes, Klebsiella pneumoniae, or Klebsiella oxytoca) and excluded if they were less than 18 years old. Results A total of 634 unique patients were included. Of 934 positive urine cultures, the organism was resistant to nitrofurantoin in 16 (1.7%). Mean patient age was 42.7 years, 99% were women, and nearly 75% were of Hispanic, Latinx, or Spanish ethnicity. The most common comorbid conditions were pregnancy (40.5%) and diabetes (24.6%). Over 90% of organisms identified were Escherichia coli. Despite institutional guidance for 5-day nitrofurantoin courses, prescribed durations were discordant in 46% of cases. Of the 16 cases associated with a nitrofurantoin-resistant pathogen, 9 (56.3%) had recent exposure to nitrofurantoin: 3 were taking nitrofurantoin suppressive therapy for recurrent UTIs and 6 received a treatment course within the last 90 days. Nitrofurantoin-resistant pathogens included E. coli (12), Klebsiella pneumoniae (3), and Enterobacter cloacae (1). A new antibiotic was prescribed for 15 of the 16 patients. 3 patients presented to an outpatient location within 30 days of the index nitrofurantoin prescription for ongoing urinary symptoms. Conclusion Increasing guideline-concordant durations of nitrofurantoin is an important antibiotic stewardship opportunity. Despite widespread use, resistance among urinary pathogens remains uncommon and may be associated with recent nitrofurantoin exposure. Disclosures All Authors: No reported disclosures.