Recruiting
Phase 2

Sildenafil

Sponsor:

The University of Texas Medical Branch, Galveston

Code:

NCT04565925

Conditions

Spinal Cord Injuries

Urinary Incontinence

Eligibility Criteria

Sex: All

Age: 18 - 70

Healthy Volunteers: Not accepted

Interventions

Sildenafil Citrate

Placebo

Study Details

Brief summary:

The goal of this study is to determine whether administration of sildenafil will decrease urine leakage in patients with spinal cord injuries.

Conditions

Spinal Cord Injuries

Urinary Incontinence

Study ID

NCT04565925

Start date

Jul 7, 2021

Status verified date

Dec, 2025

Completion date

Dec 1, 2026

Anticipated

Primary completion date

Dec 1, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Adults with spinal cord injury (SCI), 18-75 years of age, at the time of consent
  • Have urinary incontinence (UI), with at least 3 leakage episodes/week
  • Have urodynamics assessment on file with their provider in past 3 years. If no historical data on file, subject may complete prior to study visit 1.
  • Willing and able to comply with study procedures
  • Willing and able to provide written informed consent

Exclusion Criteria:

  • In phone prescreen, delighted or pleased with current quality of life due to urinary symptoms.
  • Indwelling catheter
  • History of greater than 4 urinary tract infections per year
  • Multiple sclerosis
  • Significant heart, liver, kidney, pulmonary, blood, autoimmune or peripheral vascular disease
  • Systolic blood pressure <90 or >170, diastolic blood pressure <50 or >110 after repeated evaluation with proper cuff. This range is the acceptable range stated in the prescribing information for sildenafil (>90/50 and <170/110)
  • Active cancer
  • HIV, Hepatitis B, or Hepatitis C
  • Use of systemic nitrates, anabolic steroids, corticosteroids, or long acting PDE5 inhibitors in the past 1 month
  • Use of short acting PDE5 inhibitors in the past 1 week
  • Use of alpha blockers, anticholinergic agents, bethanechol, or other UI treatment within the past 2 weeks ( 3 weeks for long acting muscarinic receptor antagonists)
  • Known allergic reaction to any agent under investigation or required by the protocol
  • Females who are pregnant or lactating
  • Atonic bladder or high detrusor and high pelvic floor muscle pressure based on previous cystometrogram (CMG) (on file with their provider) that would place subjects at risk for kidney injury
  • Any medical condition that, in the opinion of the investigator, would place the subject at increased risk for participation

Study Design

Enrollment

24 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Sildenafil 20mg TID then Placebo TID

Subjects will be administered Sildenafil 20mg TID for 4 weeks. There will be a 2 week washout period then subjects will be administered Placebo (lactose) TID for 4 weeks.

experimental: Placebo TID then Sildenafil 20mg TID

Subjects will be administered Placebo (lactose) TID for 4 week. There will be a 2 week washout period and then subjects will be administered Sildenafil 20mg TID for 4 weeks.

Interventions

Sildenafil Citrate

Sildenafil 20mg TID for 4 weeks

Placebo

Placebo (Lactose) TID for 4 weeks

Primary outcome measure

  • Bladder Leakage as measured by 5 day bladder diary at Baseline [ Time Frame: baseline ]
  • Bladder Leakage as measured by 5 day bladder diary after 4 weeks of Sildenafil Treatment [ Time Frame: after 4 weeks of sildenafil treatment ]
  • Bladder Leakage as measured by 5 day bladder diary after 4 weeks of Placebo Treatment [ Time Frame: after 4 weeks of placebo treatment ]

Central Contacts and Locations

Central contacts

Kate M Randolph, BS

409-223-7891kmrandol@utmb.edu

Kathy Vincent, MD

409-772-2610klvincen@utmb.edu

Locations

University of Texas Medical Branch

Recruiting

Galveston, Texas, United States, 77555

Contacts

Kathleen Vincent, MD

409-772-2610klvincen@utmb.edu

Lauren Dawson, BS

409-354-9792lndawson@utmb.edu

More Information

Sponsor

The University of Texas Medical Branch, Galveston

Last update posted

Dec 16, 2025

Last verified

Dec, 2025

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by The University of Texas Medical Branch, Galveston on 2025-12-16.