An interventional study of D-Mannose and Placebo in Recurrent UTIs, Recurrent Urinary Tract Infections and Recurrent Urinary Tract Infections in Women, sponsored by University of Texas Southwestern Medical Center. Recruiting at 1 site in United States. Open to female participants aged 55 Years to 85 Years. Per ClinicalTrials.gov, last updated 2025-09-22.
Sponsored by University of Texas Southwestern Medical Center · Not applicable, Interventional, and Prevention
A randomized, double-blind, placebo-controlled, 12-month study to determine the effectiveness of D-mannose (2g daily) supplementation in rUTI (recurrent urinary tract infection) prevention in post-menopausal women.
The proposed study on D-mannose prophylaxis is designed to address a critical unmet medical need to improve the understanding and prevention of rUTI (recurrent urinary tract infection) in post-menopausal women, a population disproportionately affected by rUTI and understudied. The efficacy of D-mannose on preventing uncomplicated rUTI will be elucidated, and additional study measures (including urine culture and one-hour D-mannose test results) may help establish an ideal candidate for responding to daily D-mannose intake over time. The proposed study will follow CONSORT guidelines for randomized clinical trial studies.
Aim 1. Test the hypothesis that D-mannose provides effective rUTI prophylaxis in post-menopausal women over 6 months.
Aim 2. Test the hypothesis that D-mannose provides effective rUTI prophylaxis in post-menopausal women beyond 6 months and up to one year.
The overarching hypotheses are that (1) D-mannose will be found superior to placebo in preventing rUTI in post-menopausal women over 6 months as suggested by one prior RCT7 (Aim 1) and (2) D-mannose will remain effective for rUTI prophylaxis up to one year (Aim 2).
Ninety (90) women currently UTI-free and with a history of uncomplicated rUTI, defined as ≥ 2 symptomatic UTIs in 6 months or ≥ 3 symptomatic UTIs in 12 months, will be enrolled and randomized (2:1 ratio) to receive D-mannose (2g, i.e., 4 x 500mg capsules) or placebo daily for 12 months.
803 studies on the registry are indexed under Urinary Tract Infections; 133 are open to participants now.
This study's planned enrollment of 90 is below the median of 131 across 560 interventional studies indexed under Urinary Tract Infections.
Browse Urinary Tract Infections studies →University of Texas Southwestern Medical Center is the lead sponsor of 1,010 studies on the registry; 199 are open to participants now.
Of its 139 completed or terminated interventional studies of FDA-regulated products, 105 (76%) have results posted.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Box 1 Supplements to avoid
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
A planned gap after a treatment, so that its effects can lessen before the study treatment or a study assessment. Ask the study team and the doctor who prescribed it before changing any medicine.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Postmenopausal
Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Washout period
A planned gap after a treatment, so that its effects can lessen before the study treatment or a study assessment. Ask the study team and the doctor who prescribed it before changing any medicine.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Dietary Supplement: D-Mannose
Dietary Supplement: D-Mannose
Dietary Supplement: Placebo
Dietary Supplement: Placebo
D-mannose (2g, i.e., 4 x 500mg capsules) daily for 12 months.
Placebo daily for 12 months.
Failure rate
To determine whether prophylaxis with D-mannose reduces the incidence of UTI episodes compared to placebo. "Failure rate," defined as having 2 UTIs in 6 months or 3 in one year.
Time frame: Through study completion, an average of 5 years
Number of UTI antibiotic treatments
To investigate if D-mannose reduces the need for antibiotic use due to recurrent UTIs (measured as number of antibiotic courses for symptomatic culture-proven UTI episodes) compared to placebo. Number of UTI antibiotic treatments during the 6 months of treatment. If the participant receives \>1 antibiotic course for UTI without symptom relief, it is regarded as one episode and counted as one antibiotic treatment. If there has been an asymptomatic period of at least 14 days in between two UTI antibiotic courses, this will be regarded as a new antibiotic treatment.
Time frame: Through study completion, an average of 5 years
Symptom severity
To investigate if D-mannose reduces the severity of UTI symptoms compared to placebo. Record symptom severity using a validated UTI symptom assessment questionnaire.
Time frame: Through study completion, an average of 5 years
Serious adverse events associated with D-mannose
To determine the frequency of serious adverse events associated with D-mannose. Number of participants who experienced adverse events \>= Grade 3, as defined by Common Terminology Criteria for Adverse Events by CTCA version 5.0.
Time frame: Through study completion, an average of 5 years
Plan to share: No
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