INTRODUCTION AND OBJECTIVES: AUA guidelines list fluoroquinolones (FQ) and trimethoprim-sulfamethoxazole (TMP-SMX) as first-line prophylactic antibiotics for endoscopic procedures involving manipulation of the genitourinary tract, but also note that a randomized comparison of ciprofloxacin and IV cefazolin found similar rates of postoperative bacteriuria. Based on this finding, and our institution's antibiogram showing decreasing sensitivity to ciprofloxacin, intravenous cefazolin is used as our default perioperative antibiotic (absent culture data to preclude it). We performed a retrospective analysis to determine if perioperative IV cefazolin is appropriate prophylaxis.METHODS: An Epic report was generated for the past 2 years to identify patients who returned to the hospital within 60 days of an endoscopic procedure with a diagnosis matching an ICD-10 code consistent with urosepsis, urinary tract infection, or acute cystitis (R65.2, A41, A40, N39.0, N30.0, and B37.4). Patients admitted directly from the operating room were excluded. All endourologic cases from the past two years were recorded along with perioperative antibiotics. Diagnostic cystoscopies and percutaneous procedures were excluded. Culture data, if available, was reviewed for every patient who returned. Chi-square tests were used to determine significance.RESULTS: 1462 endoscopic procedures met criteria for analysis. 1019 received cefazolin perioperatively (69.7%), 26 FLQ (1.8%), 2 TMP-SMX (0.1%) and 415 (28.4%) other antibiotics. 51 patients returned to the hospital within 60 days (3.5%). Of these, 36 had received cefazolin (70.6%); 1 FLQ (1.9%), none (0%) TMP-SMX, and 14 (27.4%) other antibiotics. The proportions of perioperative antibiotics did not significantly differ between the patients who returned to the hospital and those who did not. Positive cultures with sensitivities were available for 34 of the readmitted patients. 27 (79.4%) showed resistance to cefazolin, 18 (52.9%) FLQ, and 23 (67.6%) TMP-SMX.CONCLUSIONS: The proportions of patients who returned with infection did not differ between FLQ, TMP-SMX, or, notably, broader antibiotic regimens. The return rate in our analysis is consistent with rates reported by other institutions following endoscopic procedures. The majority of those who returned with infections were resistant to either cefazolin, FLQ, or TMP-SMX. These data suggest that cefazolin is a non-inferior and comparable choice for perioperative infection prophylaxis, especially in settings with increasing resistance to AUA guideline first-line agents.