Treatment of Pyelonephritis With or Without a Dose of IV Antibiotics in the Emergency Department

Introduction: Infectious Diseases Society of America (IDSA) guidelines generally recommend an initial dose of an intravenous (IV) antibiotic before switching to oral therapy in patients with pyelonephritis. This study evaluated whether IV antibiotics improve outcomes in outpatient treatment. The objective of this study was to assess the impact of IV antibiotics given in the emergency department on outcomes for patients with acute pyelonephritis who were discharged from the emergency department (ED).


Methods: This retrospective cohort study reviewed 4,398 ED charts from January 2022 to June 2023. Adult patients with acute pyelonephritis were identified using ICD-10 codes or clinical criteria (urine culture ≥100,000 CFUs/mL or >10 WBCs plus two symptoms). Exclusions included pregnancy, catheters, urinary obstruction, renal transplants, prior antibiotics within seven days, and immunocompromised status. The primary outcome was a 14-day ED revisit. Secondary outcomes included hospital admissions, recurrent UTIs, and subgroup analysis by antibiotic class and sex.


Results: Of 179 patients included, 79 received IV antibiotics and 100 did not. ED revisits within 14 days occurred in 15.2% of the IV group and 10% of the non-IV group (p=0.29). Admissions occurred in 2.5% vs. 1%, and recurrent UTIs in 8.9% vs. 6%, respectively. No significant differences were found by antibiotic class or sex.


Conclusions: This study suggests that administering intravenous antibiotics prior to oral therapy in patients with acute pyelonephritis may not significantly improve short-term outcomes such as emergency department revisits, hospital admissions, or recurrent urinary tract infections. The findings challenge current IDSA guidelines, which recommend IV antibiotics in certain cases, particularly when fluoroquinolone resistance is high. These results highlight the need for further research to better define which patient populations, if any, may benefit from IV antibiotics, and support a more personalized treatment approach. Ultimately, this study advocates optimizing antibiotic stewardship and reconsidering the routine use of IV antibiotics in outpatient management of pyelonephritis.