Phase 3
N=271
Efficacy of Amitriptyline for Painful Bladder Syndrome (PBS)
Bladder Diseases · Interstitial Cystitis
Bottom Line
View on ClinicalTrials.gov: NCT00124306 ↗Enrolled (actual)
271
Serious AEs
1.8%
Results posted
Oct 2025
Primary outcome: Primary: Global Response Assessment (GRA) — 74; 61; 61; 75 Participants
Study Design & Population
- Study type
- Interventional
- Phase
- Phase 3
- Interventions
- Amitriptyline (Drug); Placebo (Other)
- Age
- Adult, Older Adult · 18+ yrs
- Sex
- All
- Sponsor
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Primary completion
- Apr 2008
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Global Response Assessment (GRA) |
74; 61; 61; 75 | — |
| SECONDARY Changes in Quality of Life Measures From Baseline to 12 Weeks |
-2.6; -2.3; -3.0; -2.5; -3.5; -2.6 | — |
| SECONDARY Change in Urinary Symptoms Measures |
-4.8; -3.3; -5.2; -3.9; -13.1; -9.3 | — |
| SECONDARY Adherence to Study Drug and Urinary Educational/Behavioral Program (EBMP Educational/Behavioral Modification Program) |
62; 98; 27; 20; 46; 18 | — |
| SECONDARY Change in Nighttime Voiding From Baseline to 12 Weeks |
-0.9; -0.9 | — |
Summary
This is a randomized clinical trial study to test the efficacy and safety of amitriptyline in the treatment of patients newly diagnosed with painful bladder syndrome (PBS). PBS is defined by symptoms--frequent urination day and night and increasing pain as the bladder fills--according to the International Continence Society. The syndrome includes interstitial cystitis (IC), which has been estimated to affect as many as 700,000 people, mostly women. Estimates for PBS vary widely, but as many as 10 million people may suffer from this condition. Although amitriptyline is a Food and Drug Administration (FDA)-approved medication used for depression, the way it works makes it useful for treating the pain of fibromyalgia, multiple sclerosis, and other chronic pain syndromes. Prior small studies in interstitial cystitis (IC) suggested the drug may be a wise choice for this syndrome as well, because it blocks nerve signals that trigger pain and may also decrease muscle spasms in the bladder, helping to relieve the symptoms of pain and frequent urination.
Eligibility Criteria
Inclusion Criteria
- Participant must report bladder pain/discomfort score of 3 or greater on a 0-10 Likert scale over the previous 4 weeks.
- Participant must report a symptom score of abnormal urinary frequency of 3 or greater on a 0-10 Likert scale over the previous 4 weeks.
- Symptoms of abnormal urinary frequency and bladder pain/discomfort must have been present for at least six weeks prior to screening visit.
Exclusion Criteria
- Known allergy or intolerance to amitriptyline or any of its components.
- Currently receives treatment with amitriptyline or other tricyclic antidepressant, selective serotonin reuptake inhibitor (SSRI) or serotonin and norepinephrine reuptake inhibitor (SNRI), or monoamine oxidase (MAO) inhibitor antidepressants.
- Previous treatment with amitriptyline or other tricyclics, hydroxyzine or other antihistamines for bladder symptoms; pentosanpolysulfate; DMSO or any other intravesical therapy, biofeedback or pelvic floor physical therapy for PBS symptoms
Data sourced from ClinicalTrials.gov (NCT00124306). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.