CI

At a glance

ClinicalIndex Comparison Record
Phase 3Completed· 271 enrolled
Drug / intervention
Amitriptyline +1 moredrug
Likely dose
Amitriptyline titrated over 6 weeks to maximum dose of 75 mgAI-extracted
Key inclusion· 3
  • Bladder pain or discomfort score ≥3 on 0-10 scale over previous 4 weeks
  • Abnormal urinary frequency score ≥3 on 0-10 scale over previous 4 weeks
  • Symptoms present for at least 6 weeks prior to screening
Key exclusion· 3
  • Known allergy or intolerance to amitriptyline or its components
  • Currently receiving amitriptyline, other tricyclic antidepressants, SSRIs, SNRIs, or MAOIs
  • Prior treatment with tricyclics, hydroxyzine, antihistamines, pentosanpolysulfate, DMSO, intravesical therapy, biofeedback, or pelvic floor physical therapy for PBS

Standardized by ClinicalIndex from the ClinicalTrials.gov record · verify against the source.

Search/NCT00124306
NCT00124306Phase 3Completed

A Randomized Multicenter Clinical Trial to Evaluate the Efficacy of Amitriptyline for the Treatment of Painful Bladder Syndrome (PBS) in Newly Diagnosed Patients

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)·interventional·Posted Jul 27, 2005·Updated Jan 12, 2026

In Brief

A Phase 3 clinical trial evaluating Amitriptyline and Placebo for Bladder Diseases and Interstitial Cystitis. Completed, enrolled 271 participants across 10 sites in 2 countries.

Detailed 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.

Study Details

Study Typeinterventional
Allocation--
Masking--
Primary Purpose--
CountriesCanada, United States

Timeline

Phase 3CompletedFinished
20052006200720082009201020112012201320142015201620172018201920202021202220232024202520262027
First PostedJul 27, 2005
Enrollment StartFeb 1, 2005
Primary CompletionApr 1, 2008
Study CompletionDec 1, 2008
TodayJul 2, 2026
Enrollment to primary: 3.2 yearsPosted 20.9 years ago

Interventions

Amitriptylinedrug

Amitriptyline will be titrated over a 6-week period as tolerated, to a maximum dose of 75mg. During the 6-week titration period, the patient who cannot tolerate a scheduled increased dose may adjust the medication dose for tolerance by tapering down one 25mg tablet.

Placeboother

Placebo will be dosed exactly as active arm.