Evaluation of Local Prescribing Patterns and Antimicrobial Resistance in Women With Acute Pyelonephritis Caused by E. coli.

Background: Owing to increasing local Escherichia coli resistance and current guidelines for the treatment of acute pyelonephritis (APN) over 14 years old, an evaluation of local prescribing patterns is warranted.

Objective: The purpose of this study was to evaluate local prescribing patterns and appropriateness of antibiotics in acute uncomplicated APN.

Methods: This is a retrospective cohort study of female patients aged 18 to 89 years diagnosed with APN and positive urine culture growing E. coli. Exclusion criteria included pregnancy, immunocompromised status, and complicated urinary tract infections. Outcomes included antibiotic appropriateness and its effects on hospital admission, hospital length of stay, and 30-day readmission.

Results: Between 2017 and 2022, 308 female patients were diagnosed with APN and had positive urine cultures, with 104 seen only in the emergency department (ED) and 109 admitted to the hospital. Patients seen in the ED had a significant increase in E. coli resistance to discharge antibiotics (12.5% vs 2.8%, P = 0.0070). In those patients discharged on antibiotics resistant to E. coli, significantly more patients returned to the ED in 30 days (31.3% vs 10.7%, P = 0.0155).

Conclusion and relevance: Patients seen only in the ED were more likely to have resistant organisms to discharge antibiotics compared with those admitted to the hospital. Patients discharged on antibiotics resistant to E. coli had a 3-fold increase in returning to the ED within 30 days regardless of admitted location. Follow-up of all cultures should be performed, and patients resistant to discharge antibiotics should be contacted and antibiotic regimens changed.