Recruiting

Methenamine Hippurate vs. Antibiotic

Sponsor:

Women and Infants Hospital of Rhode Island

Code:

NCT06953271

Conditions

Overactive Bladder (OAB)

Urinary Tract Infection (Diagnosis)

Eligibility Criteria

Sex: Female

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Methenamine Hippurate

Typically prescribed oral antibiotic prophylaxis

Study Details

Brief summary:

The goal of this clinical trial is to compare methenamine hippurate prophylaxis to routine antibiotic prophylaxis following onabotulinumtoxinA (BOTOX-A) injections in women with overactive bladder (OAB). Participants will be randomly selected to receive one of the two post-procedural prophylaxis medications. The primary outcome measure will be urinary tract infection (UTI) rates within 30 days from the BOTOX-A procedure. Secondary outcomes will assess patient satisfaction with the two post-procedural prophylaxis medications.

Conditions

Overactive Bladder (OAB)

Urinary Tract Infection (Diagnosis)

Study ID

NCT06953271

Start date

Aug 1, 2025

Status verified date

Aug, 2025

Completion date

Apr 1, 2027

Anticipated

Primary completion date

Jan 30, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Female

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • 18 years of age or older
  • undergoing intradetrusor BOTOX-A injections in the office setting for overactive bladder

Exclusion Criteria:

  • cisgender male individuals
  • neurogenic reasons for bladder symptoms (i.e. spinal cord injury, multiple sclerosis, etc.)
  • known allergy and/or contraindication to methenamine hippurate
  • currently already taking methenamine hippurate at the time of the procedure
  • taking antibiotics for any reason on the day of their BOTOX-A procedure
  • positive UTI at time of procedure (positive dip at time of procedure)
  • history of bladder cancer
  • history of pelvic radiation
  • surgically altered detrusor muscle
  • pre-procedural need for catheterization
  • diagnosis of Interstitial Cystitis/Painful Bladder Syndrome (IC/PBS)
  • pregnant or lactating individuals

Study Design

Enrollment

164 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Prevention

Interventions and Outcome Measures

Arms

active comparator: Typically prescribed oral antibiotic prophylaxis

Typically prescribed oral antibiotic prophylaxis for the purposes of this study is defined as oral antibiotics that are routinely prescribed following BOTOX-A injections for UTI prophylaxis. Given known heterogeneity in antibiotic prophylaxis type and duration as well as the lack of standardized antibiotic recommendations for intradetrusor BOTOX-A injections, the choice of antibiotic prophylaxis is deferred to the physician performing the BOTOX-A injections. The duration of treatment will be standardized to three days, based off previous studies.

experimental: Methenamine hippurate prophylaxis

Participants in the experimental arm will receive methenamine hippurate 1 gram by mouth twice daily for three days.

Interventions

Methenamine Hippurate

Drug: Methenamine hippurate 1 gram by mouth twice daily for three days.

Typically prescribed oral antibiotic prophylaxis

Drug: typically prescribed oral antibiotic prophylaxis following intradetrusor BOTOX-A injections. This includes, but is not limited to, antibiotic medications such as nitrofurantoin, amoxicillin/clavulanic acid, and trimethoprim/sulfamethoxazole. Dosage will be determined per usual care. Duration of treatment will be standardized to three days.

Primary outcome measure

  • Acute Urinary Tract Infection [ Time Frame: Date of the BOTOX-A injection to 30 days after the procedure ]

Central Contacts and Locations

Central contacts

Colin Russell, MD, MPH

401-453-7560CoRussell@wihri.org

Kyle Wohlrab, MD

401-453-7560KWohlrab@CareNE.org

Locations

Women & Infants Hospital

Recruiting

Providence, Rhode Island, United States, 02903

Contacts

Colin Russell, MD, MPH

401-453-7560CoRussell@wihri.org

Principal Investigator:

Vivian Sung, MD, MPH

More Information

Sponsor

Women and Infants Hospital of Rhode Island

Last update posted

Aug 19, 2026

Last verified

Aug, 2025

Keywords

  • Overactive Bladder
  • onabotulinumtoxinA
  • Methenamine
  • Urinary Tract Infection
  • BOTOX-A
  • UTI
  • OAB

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Women and Infants Hospital of Rhode Island on 2026-08-19.