A comparison of empiric therapy with cefazolin versus ceftriaxone for patients with complicated urinary tract infections in a tertiary care veterans affairs medical center.

Background: Data are limited regarding use of narrow-spectrum agents for the treatment of complicated urinary tract infections (cUTIs). We sought to evaluate cefazolin compared with ceftriaxone for the empiric treatment of patients with cUTIs in an inpatient setting.

Methods: We conducted a retrospective, single-center, cohort study involving patients with cUTI treated with cefazolin or ceftriaxone at a Veterans Affairs (VA) medical center between November 1, 2019 and September 30, 2022. The primary outcome was 30-day clinical success, defined as resolution of signs and symptoms of infection without re-initiation of antibiotics during hospitalization or relapse within 30 days after cUTI diagnosis. Secondary outcomes included hospital length of stay and Clostridioides difficile infection (CDI) within 30 days of the end of antibiotic therapy.

Results: We identified 113 patients with cUTI treated with cefazolin (n = 52) or ceftriaxone (n = 61) meeting study criteria. The study arms had similar demographics, although patients treated with ceftriaxone more frequently had subjective fever on admission or nephrolithiasis while cefazolin-treated patients had more altered mental status as the only UTI symptom reported, urinary catheter, and had a single dose of another antibiotic prior to starting the study medication. Clinical success was achieved in 47/52 (90%) and 53/61 (87%) in the cefazolin and ceftriaxone groups, respectively (P = 0.56). Additionally, there were no statistically significant differences in length of stay and development of CDI.

Conclusions: In this retrospective cohort study of patients with cUTI at a VA medical center, empiric therapy with cefazolin appears to be a safe and effective treatment option.