Clinical and bacteriological efficacy of pivmecillinam treatment for uncomplicated urinary tract infections caused by ESBL-producing Escherichia coli: a prospective, multicentre, observational cohort study.

Objectives: To compare the clinical and bacteriological outcomes of pivmecillinam treatment for community-acquired urinary tract infections (UTIs) caused by ESBL-producing Escherichia coli versus non-ESBL-producing E. coli in an outpatient setting.

Methods: A prospective, multicentre, observational cohort study of women aged ≥16 years, with pivmecillinam-treated community-acquired UTIs caused by E. coli with or without ESBL production, recruited from primary care, was conducted in the period from April 2013 to August 2016. Eighty-eight women (mean age 49.4 years) with community-acquired UTIs caused by ESBL-producing E. coli were compared with a control group of 74 women (mean age 50.1 years).

Trial registration: Regional Committees for Medical and Health Research Ethics (REC) in Norway, ID 2011/2214, and ClinicalTrials.gov, ID NCT01531023.

Results: The median time until symptom resolution after treatment initiation was 5 days for the ESBL cases and 3 days for the non-ESBL controls (P < 0.01). The proportion of women warranting a second antibiotic prescription in the follow-up period was higher for the ESBL cases [30/88 (34.1%) versus 10/72 (13.9%), P < 0.01]. Persistent bacteriuria was non-significantly more common among ESBL cases than in the control group [15/81 (18.5%) versus 6/67 (9.0%), P = 0.10]. A pivmecillinam dosage of 200 mg given three times daily for ≤5 days was associated with treatment failure (OR 4.77, 95% CI 1.40-19.44, P = 0.03) for the ESBL E. coli group. For the subgroup treated with 400 mg of pivmecillinam given three times daily there was no significantly increased OR for treatment failure between ESBL cases and the control group irrespective of treatment duration.

Conclusions: Pivmecillinam given at 400 mg three times daily gave comparable clinical and bacteriological cure rates in women with community-acquired E. coli UTIs irrespective of ESBL production.