Clinical Impact of Discordant Prescribing of Fluoroquinolones and Alternative Treatments in Escherichia coli Pyelonephritis.

INTRODUCTION: The emergence of resistant Escherichia coli to fluoroquinolones (FQs) is of growing concern, yet the latest guidelines for the treatment of pyelonephritis still recommend FQs as first-line treatment. Our primary objective was to determine the impact of discordant prescribing of FQs in E coli pyelonephritis on hospital length of stay (LOS) and early clinical response (ECR).

METHODS: We retrospectively compared discordant and concordant prescribing of FQs for LOS and ECR. We also compared FQs, ceftriaxone, piperacillin/tazobactam, and carbapenems for these clinical outcomes.

RESULTS: Forty-nine patients included in the comparison between discordant (n = 9) and concordant (n = 40) prescribing of FQs. There was significantly lower ECR in patients with discordant prescribing of FQs (38 of 40, 95% vs 5 of 9, 55.6%, P = .0074) and a trend toward longer LOS (4 [2.3] days vs 3 [2.0] days, P = .0571). Illness severity, estimated using Simplified Acute Physiology Score (SAPS II) score, was similar between groups (P = .717).

CONCLUSION: There was a significantly decreased ECR and a trend toward increased LOS when FQs were used in FQ-resistant E coli. Regarding alternative treatment for E coli pyelonephritis, ceftriaxone was as effective as concordant FQs and significantly better than discordant FQs.