A Phase 4 interventional study of low-dose naltrexone and Placebo oral tablet in Interstitial Cystitis, Painful Bladder Syndrome and Bladder Pain Syndrome, sponsored by Endeavor Health. Terminated at 1 site in United States. Open to female participants aged 18 Years to 110 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-03-07.
Sponsored by Endeavor Health · Phase 4, Interventional, and Treatment
Interstitial cystitis/painful bladder syndrome (IC/PBS) is a debilitating condition with symptoms of urinary urgency, frequency, nocturia (waking up at night to void), and pain, without evidence of urinary tract infection or other identifiable causes. IC/PBS often coexists with other chronic pain syndromes, such as irritable bowel syndrome, chronic fatigue syndrome, and fibromyalgia.
Several treatments exist for IC/PBS; some are not effective, others are time consuming for patients to receive, some can take weeks to months before they become effective, and many have risks associated with them. Low-dose naltrexone (LDN) has demonstrated improvement of symptoms in conditions associated with IC/PBS. LDN is defined as less than 5mg of naltrexone. Some adverse effects have been reported with LDN, the most common are vivid dreams, nightmares, and insomnia.
The investigators hypothesis LDN will have greater than 30% reduction in symptoms as defined by the Interstitial Cystitis Symptom Index in patients diagnosed with IC/PBS from baseline when compared to placebo. The 30% reduction in pain is a standard outcome measure in the pain literature. This improvement has been seen in prior studies where LDN was used to treat pain syndromes.
This will be a randomized double-blinded placebo-controlled prospective trial. Patients meeting diagnostic criteria for IC/PBS by American Urologic Association (AUA) guidelines will be eligible, and then must then meet all applicable inclusion and exclusion criteria. Study participants will sign a consent, complete several questionnaires, give a blood sample to measure liver function tests, and once at home, complete a 24-hour bladder diary.
Participants will be randomized to receive either placebo or study medication. Participants will be instructed to take one capsule nightly for two weeks, then increase to two capsules nightly for four weeks. They will be given a log to record the date and time they take the medication. All study participants will also receive first-line behavioral therapy for IC/PBS of a bladder diet and bladder drills.
After six weeks, participants will complete a second bladder diary. They will then complete the exit study questionnaires, have a second liver function test, return any unused medication, and meet with their doctor to discuss conventional treatment options for IC/PBS.
236 studies on the registry are indexed under Cystitis, Interstitial; 35 are open to participants now.
This study's enrollment of 3 is below the median of 51 across 158 interventional studies indexed under Cystitis, Interstitial.
Browse Cystitis, Interstitial studies →Endeavor Health is the lead sponsor of 111 studies on the registry; 34 are open to participants now.
Of its 12 completed or terminated interventional studies of FDA-regulated products, 9 (75%) have results posted.
Counted across the registry records on this site, refreshed daily.
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:
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.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
2mg low-dose naltrexone capsules
Drug: low-dose naltrexone
Placebo capsules
Drug: Placebo oral tablet
2mg of low-dose naltrexone nightly for 2 weeks, then 4mg of low-dose naltrexone nightly for 4 weeks
1 capsule nighty for 2 weeks, then 2 capsules nightly for 4 weeks
Interstitial Cystitis Symptom Index
The effect of LDN (low-dose naltrexone) in decreasing symptoms associated with IC/PBS (interstitial cystitis/painful bladder syndrome) when treating with low-dose naltrexone as scored by the Interstitial Cystitis Symptom Index as compared to placebo. Scores are from 0 to 20, with lower scores indicating less symptoms associated with IC/PBS.
Time frame: six weeks
Visual Analog Scale
The effect of LDN in decreasing pain associated with IC/PBS when treating with low-dose naltrexone as scored by visual analog scale as compared with placebo. Scores are from 0 to 10, with lower scores indicating less pain.
Time frame: six weeks
Change in Interstitial Cystitis Problem Index
The changes in IC/PBS associated problems when treating interstitial cystitis/painful bladder syndrome with low-dose naltrexone as scored by the Interstitial Cystitis Problem Index, prior to initiating treatment and at the conclusion of 6 weeks of treatment. Scores are from 0-16, with lower scores indicating a better score, with fewer problems associated with IC/PBS. The change was calculated from two time points as the value prior to initiating treatment minus the value at the conclusion of 6 weeks of treatment.
Time frame: prior to initiating treatment and at the conclusion of 6 weeks of treatment
Change in Urinary Frequency
The change in number of patient voids during the day when comparing LDN against placebo as determined from 24 hour bladder diary performed by patient prior to initiating treatment and at the conclusion of 6 weeks of treatment. The change was calculated from two time points as the value prior to initiating treatment minus the value at the conclusion of 6 weeks of treatment.
Time frame: prior to initiating treatment and at the conclusion of 6 weeks of treatment
Change in Number of Nocturia
The change in number of patient voids during at night when comparing LDN against placebo as determined from 24 hour bladder diary performed by patient prior to initiating treatment and at the conclusion of 6 weeks of treatment. The change was calculated from two time points as the value prior to initiating treatment minus the value at the conclusion of 6 weeks of treatment.
Time frame: prior to initiating treatment and at the conclusion of 6 weeks of treatment
Change in Pelvic Pain and Urgency/Frequency Symptoms
The change in pelvic pain and urgency/frequency symptoms as measured on the Pelvic Pain and Urgency/Frequency Patient Symptom Scale, prior to initiating treatment and at the conclusion of 6 weeks of treatment. Scores can range from 0-23, with higher scores indicating more severe symptoms associated with IC/PBS. The change was calculated from two time points as the value prior to initiating treatment minus the value at the conclusion of 6 weeks of treatment.
Time frame: prior to initiating treatment and at the conclusion of 6 weeks of treatment
Change in Pelvic Pain and Urgency/Frequency Bother
The change in pelvic pain and urgency/frequency bother as measured on the Pelvic Pain and Urgency/Frequency Patient Symptom Scale, prior to initiating treatment and at the conclusion of 6 weeks of treatment. Scores can range from 0-12, with higher values corresponding to more bother from IC/PBS symptoms. The change was calculated from two time points as the value prior to initiating treatment minus the value at the conclusion of 6 weeks of treatment.
Time frame: prior to initiating treatment and at the conclusion of 6 weeks of treatment
Patient Perceived Quality of Life: SF-36
Patient perceived quality of life as measured by the medical outcomes study short form 36 (SF-36). Higher scores indicate a more favorable health status. There are 8 subscales, which when averaged, include a score from 0-100.
Time frame: six weeks
Adverse Effects
The percentage of patients complaining of adverse effects from LDN including vivid dreams, nightmares, insomnia, GI disturbances such as stomach cramps or diarrhea, agitation, anxiety, flu-like symptoms and headaches.
Time frame: six weeks
Medication Tolerability
The percentage of patients who discontinue the study medication measured by the tolerability survey.
Time frame: six weeks
Number of Days With Pain Medications
The number of days with pain medication use while using LDN, as determined by a pain medication diary.
Time frame: six weeks
| Milestone | Low-dose Naltrexone | Placebo |
|---|---|---|
| Started | 1 | 2 |
| Completed | 1 | 1 |
| Not completed | 0 | 1 |
| Withdrew: Withdrawal by subject | 0 | 1 |
The effect of LDN (low-dose naltrexone) in decreasing symptoms associated with IC/PBS (interstitial cystitis/painful bladder syndrome) when treating with low-dose naltrexone as scored by the Interstitial Cystitis Symptom Index as compared to placebo. Scores are from 0 to 20, with lower scores indicating less symptoms associated with IC/PBS.
| score on a scale | Low-dose Naltrexone | Placebo |
|---|---|---|
| Interstitial Cystitis Symptom Index | 6 | 5 |
The effect of LDN in decreasing pain associated with IC/PBS when treating with low-dose naltrexone as scored by visual analog scale as compared with placebo. Scores are from 0 to 10, with lower scores indicating less pain.
| score on a scale | Low-dose Naltrexone | Placebo |
|---|---|---|
| Visual Analog Scale | 0 | 0 |
The changes in IC/PBS associated problems when treating interstitial cystitis/painful bladder syndrome with low-dose naltrexone as scored by the Interstitial Cystitis Problem Index, prior to initiating treatment and at the conclusion of 6 weeks of treatment. Scores are from 0-16, with lower scores indicating a better score, with fewer problems associated with IC/PBS. The change was calculated from two time points as the value prior to initiating treatment minus the value at the conclusion of 6 weeks of treatment.
| score on a scale | Low-dose Naltrexone | Placebo |
|---|---|---|
| Change in Interstitial Cystitis Problem Index | 4 | 11 |
The change in number of patient voids during the day when comparing LDN against placebo as determined from 24 hour bladder diary performed by patient prior to initiating treatment and at the conclusion of 6 weeks of treatment. The change was calculated from two time points as the value prior to initiating treatment minus the value at the conclusion of 6 weeks of treatment.
| voids per day | Low-dose Naltrexone | Placebo |
|---|---|---|
| Change in Urinary Frequency | 8 | 11 |
The change in number of patient voids during at night when comparing LDN against placebo as determined from 24 hour bladder diary performed by patient prior to initiating treatment and at the conclusion of 6 weeks of treatment. The change was calculated from two time points as the value prior to initiating treatment minus the value at the conclusion of 6 weeks of treatment.
| voids per night | Low-dose Naltrexone | Placebo |
|---|---|---|
| Change in Number of Nocturia | 3 | 2 |
The change in pelvic pain and urgency/frequency symptoms as measured on the Pelvic Pain and Urgency/Frequency Patient Symptom Scale, prior to initiating treatment and at the conclusion of 6 weeks of treatment. Scores can range from 0-23, with higher scores indicating more severe symptoms associated with IC/PBS. The change was calculated from two time points as the value prior to initiating treatment minus the value at the conclusion of 6 weeks of treatment.
| score on a scale | Low-dose Naltrexone | Placebo |
|---|---|---|
| Change in Pelvic Pain and Urgency/Frequency Symptoms | 3 | 7 |
The change in pelvic pain and urgency/frequency bother as measured on the Pelvic Pain and Urgency/Frequency Patient Symptom Scale, prior to initiating treatment and at the conclusion of 6 weeks of treatment. Scores can range from 0-12, with higher values corresponding to more bother from IC/PBS symptoms. The change was calculated from two time points as the value prior to initiating treatment minus the value at the conclusion of 6 weeks of treatment.
| score on a scale | Low-dose Naltrexone | Placebo |
|---|---|---|
| Change in Pelvic Pain and Urgency/Frequency Bother | 1 | 7 |
Patient perceived quality of life as measured by the medical outcomes study short form 36 (SF-36). Higher scores indicate a more favorable health status. There are 8 subscales, which when averaged, include a score from 0-100.
| score on a scale | Low-dose Naltrexone | Placebo |
|---|---|---|
| Patient Perceived Quality of Life: SF-36 | 86 | 84 |
The percentage of patients complaining of adverse effects from LDN including vivid dreams, nightmares, insomnia, GI disturbances such as stomach cramps or diarrhea, agitation, anxiety, flu-like symptoms and headaches.
| Participants | Low-dose Naltrexone | Placebo |
|---|---|---|
| Adverse Effects | 0 | 0 |
The percentage of patients who discontinue the study medication measured by the tolerability survey.
| Participants | Low-dose Naltrexone | Placebo |
|---|---|---|
| Medication Tolerability | 0 | 0 |
The number of days with pain medication use while using LDN, as determined by a pain medication diary.
| days | Low-dose Naltrexone | Placebo |
|---|---|---|
| Number of Days With Pain Medications | 13 | 42 |
Collected over At two weeks and at four weeks, an average up to six weeks. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Low-dose Naltrexone | 0/1 (0%) | 0/1 (0%) | 0/1 (0%) |
| Placebo | 0/2 (0%) | 0/2 (0%) | 0/2 (0%) |
| Age, Continuous(years) | Low-dose Naltrexone | Placebo | Total |
|---|---|---|---|
| Mean | 52 | 52 ± 8.5 | 52 ± 6 |
| Sex: Female, Male(Participants) | Low-dose Naltrexone | Placebo | Total |
|---|---|---|---|
| Female | 1 | 2 | 3 |
| Male | 0 | 0 | 0 |
| Ethnicity (NIH/OMB)(Participants) | Low-dose Naltrexone | Placebo | Total |
|---|---|---|---|
| Hispanic or Latino | 0 | 1 | 1 |
| Not Hispanic or Latino | 1 | 1 | 2 |
| Unknown or Not Reported | 0 | 0 | 0 |
| Race (NIH/OMB)(Participants) | Low-dose Naltrexone | Placebo | Total |
|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 |
| Asian | 0 | 1 | 1 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 |
| Black or African American | 0 | 0 | 0 |
| White | 0 | 0 | 0 |
| More than one race | 0 | 0 | 0 |
| Unknown or Not Reported | 1 | 1 | 2 |
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Studies of the drug tested here: Naltrexone