Extended high-dose antibiotics plus methenamine hippurate versus standard low-dose antibiotics or methenamine hippurate for women with chronic urinary tract infection

EAT-UP - Extended Antibiotic Treatment in Chronic UTI Patients; a Phase II Safety and Efficacy Trial

Phase 2 Interventional University College, London · NCT07202949

This study will try longer courses of higher-dose antibiotics together with methenamine hippurate to see if they reduce daily symptoms better than the usual low-dose antibiotics or methenamine in adult women with chronic urinary tract infection.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment192 (estimated)
Ages18 Years and up
SexFemale
SponsorUniversity College, London Academic / other
Locations5 sites (London and 4 other locations)
Trial IDNCT07202949 on ClinicalTrials.gov

What this trial studies

EAT-UP is a UK, multi-centre, randomized, open-label phase II trial enrolling 192 adult female participants with chronic urinary tract infection. Participants are randomly assigned to two arms: a high (treatment) dose antibiotic chosen by the clinician plus methenamine hippurate, or a standard low-dose prophylactic antibiotic or methenamine hippurate alone. Medications are taken for 12 weeks with clinic visits and assessments every four weeks, and participants provide questionnaires and blood, urine, and perineal samples. The trial focuses on symptom reduction and tolerability in people with persistent daily urinary symptoms and evidence of urinary inflammation on microscopy.

Who should consider this trial

Good fit: Adult females (≥18 years) with at least three months of daily persistent urinary storage or pain symptoms judged to be chronic UTI, a screening urine microscopy showing ≥20 WBC/µL, eGFR ≥45 mL/min/1.73m2, and ability to attend study visits in the UK.

Not a fit: Patients with structural or functional urinary tract abnormalities, males, those with severe kidney impairment, pregnant people, or those whose symptoms are not due to chronic UTI are unlikely to benefit from this trial's interventions.

Why it matters

Potential benefit: If successful, this approach could reduce daily UTI symptoms and improve quality of life for women whose symptoms have not responded to current low-dose or antiseptic treatments.

How similar studies have performed: Methenamine hippurate and low-dose prophylactic antibiotics have some prior evidence for preventing recurrent UTIs, but combining extended high-dose antibiotics with methenamine for chronic daily-symptom UTI is relatively untested in randomized trials.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. A diagnosis of chronic UTI, without structural or functional urinary tract abnormality\*, defined as daily persistent symptoms affecting storage (urinary frequency, urgency or urge incontinence) and urinary tract pain symptoms (including bladder pain, urethral pain, or dysuria), for at least 3 months prior to the screening visit, with previously associated transient symptomatic improvement to antibiotic treatment for UTI, which in the opinion of the delegated clinician is secondary to chronic urinary tract infection.
2. A fresh urine microscopy examination showing ≥20 white blood cells/µl of urine at the screening visit.
3. Female\*\* patients.
4. Aged ≥18 years.
5. Screening blood result of eGFR ≥45ml/min/1.73m2.
6. Able and willing to attend trial visits and comply with all study procedures for the duration of the trial.
7. Able and willing to provide informed consent prior to any study related assessments and/or procedures.

   * A structural or functional abnormality may include kidney reflux, current or long-term catheter use, renal transplant, diversion surgery, renal stones, grade 2 or above utero-vaginal prolapse or incomplete bladder emptying.

     * For the purposes of this trial, a female will be defined as an individual assigned female at birth who has a female urinary tract.

Exclusion Criteria:

1. Inability to take at least one of the following antibiotics: Cefalexin, Nitrofurantoin, or Trimethoprim, at prophylactic and treatment dose according to NICE guidelines, and/or the Summary of Product Characteristics (such as hepatic or renal dysfunction), or any other medical contraindications.
2. Inability to take methenamine hippurate due to medical contraindications.
3. Current use of immune-modulating drugs for the treatment of chronic illnesses such as rheumatoid arthritis, chronic lung disease, any other autoimmune conditions or cancer.
4. Current use of Sodium-Glucose Transport Protein 2 (SGLT2) inhibitors\*.
5. A current diagnosis of bladder cancer.
6. A diagnosis of an active sexually transmitted infection or a recent diagnosis of a sexually transmitted infection within the last 3 months of the screening visit.
7. Previous use of an antibiotic at treatment dose as per NICE guidelines for more than 14 consecutive days for treatment of UTI in the last 3 months prior to the screening visit.
8. Pregnancy (or planned pregnancy during trial participation) and/or breastfeeding.
9. Women of childbearing potential that are unable/unwilling to use an acceptable method of contraception (as described in section 3.4.1) to avoid pregnancy for the duration of the trial and for 1 week after the last dose of trial medication.
10. Current participation in another clinical trial of a device, interventional medicinal product, advanced therapy, or surgical procedure; or previous participation within 6 months of the screening visit.
11. Any medical condition or previous treatment which in the investigator's opinion compromises the potential participant's ability to participate.

    * Patient's must not have taken a Sodium-Glucose Transport Protein 2 (SGLT2) inhibitor within 24 hours before the screening visits to be eligible for the trial.

Where this trial is running

London and 4 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Chronic Urinary Tract InfectionUrinary Tract InfectionAntibioticsUrological Diseasesmethenamine hippurateCefalexinNitrofurantoinTrimethoprim
Last reviewed 2026-06-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.