Single-dose amikacin plus 7 days of amoxicillin/clavulanate to treat acute cystitis caused by extended-spectrum beta-lactamase-producing Escherichia coli: A retrospective cohort study

Purpose: Treatment options for urinary tract infection (UTI) caused by extended-spectrum beta-lactamase (ESBL)-producing organisms are limited other than carbapenem. Accordingly, clinicians should investigate alternative antimicrobial options for limited infection. This study was performed to assess the efficacy of single-dose amikacin and a 7-day oral regimen of amoxicillin/clavulanate for the treatment of acute cystitis caused by ESBL-producing Escherichia coli and Klebsiella pneumoniae. Materials and Methods: A single-dose amikacin and 7-day oral amoxicillin/clavulanate regimen was given to all patients with acute cystitis or recurrent cystitis between May 2016 and October 2018. We conducted a retrospective cohort study assessing the efficacy of this regimen for the treatment of UTI due to ESBL-producing organisms. Both clinical and laboratory efficacy were assessed a minimum of 7 days and a maximum of 14 days after the completion of treatment. Results: A total of 47 patients were enrolled in this study. E. coli and K. pneumoniae were isolated in 44 patients (93.6%) and 3 patients (6.4%), respectively. Of the 47 enrolled, 39 patients (83.0%) showed sterile culture results on follow-up. Thirty-seven patients (78.7%) showed improvement of symptoms. Of 8 patients who showed bacterial persistence, 4 patients showed ESBL-producing E. coli, whereas 4 patients showed non-ESBL E. coli on follow-up cultures. During follow-up, 12 patients experienced the recurrence of acute cystitis with a median recurrence period of 2.5 months. Conclusions: The combination of amoxicillin/clavulanate and amikacin may be an alternative to carbapenem treatment in patients with acute cystitis caused by ESBL-producing Enterobacteriaceae.