Venlafaxine Combined With Education and Behavioral Intervention for Bladder Pain Syndrome (VEN-BPS)

A Multicenter, Open-label, Observer-blinded Randomized Controlled Trial Comparing the Efficacy and Safety of Venlafaxine Plus Education and Behavioral Modification Program Versus Education and Behavioral Modification Program Alone in Adults With Interstitial Cystitis/Bladder Pain Syndrome

This study aims to compare two treatment plans for adults with bladder pain syndrome (also called interstitial cystitis), a disease that causes long-lasting bladder pain, frequent urination and urgent need to pee. All participants will receive standardized patient education and behavioral training to relieve urinary discomfort. Half of the participants will only get this behavioral intervention, while the other half will take oral venlafaxine in addition to the same behavioral training for 12 weeks. We will check patients' pain levels, urination frequency, sleep quality, mood and daily life ability at 1, 2, 6 and 12 weeks of treatment. The main goal is to see whether adding venlafaxine can better ease bladder pain and urinary symptoms without obvious side effects. This research will provide safer and more effective treatment suggestions for patients with bladder pain syndrome.

Study Overview

• Status: Not yet recruiting
• Conditions: Interstitial Cystitis; Bladder Pain Syndrome; Chronic Pelvic Nociplastic Pain
• Intervention / Treatment: Behavioral: Education and Behavioral Modification Program (EBMP) only; Drug: Venlafaxine oral tablet combined with Education and Behavioral Modification Program (EBMP)

• Study Type: Interventional
• Enrollment (Estimated): 140
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Fang Luo FL, doctor; Phone Number: +8615560392365; Email: Litypacop@163.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

Age ≥ 18 years (all genders) Confirmed IC/BPS diagnosis fulfilling AUA 2015 and ESSIC standardized diagnostic criteria, ruled out confounding urologic disorders Predominant lower urinary tract symptoms present for most days in the past 3 months Baseline bladder/pelvic pain and urinary frequency score ≥ 3 points on 0-10 Likert scale within prior 4 weeks

Exclusion Criteria:

Symptomatic urethral stricture Active degenerative/inflammatory neurological disease altering bladder/intestinal function Uncontrolled active autoimmune disease or systemic infection Medical history of pelvic tuberculosis, pelvic radiotherapy or chemotherapy-induced cystitis History of non-cutaneous malignant tumors Current diagnosis of severe psychiatric disorders (major depressive disorder, bipolar disorder, schizophrenia, psychotic disorders) Clinically significant moderate-severe cardiac, pulmonary, hepatic or renal insufficiency Documented hypersensitivity to venlafaxine or other SNRI drugs Concurrent regular use of antibiotics or NSAIDs throughout trial period Pregnancy or breastfeeding state at screening

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Arm 1 Control Arm (n=70); Intervention Name: Education and Behavioral Modification Program (EBMP) Only Intervention Description: Standardized 12-week behavioral intervention including IC/BPS disease education, bladder irritant dietary restriction guidance, timed bladder training, pelvic floor relaxation training, stress and sleep adjustment guidance. No additional oral antidepressants, analgesics or NSAIDs permitted throughout trial. Weekly telephone follow-up for adherence monitoring.	Behavioral: Education and Behavioral Modification Program (EBMP) only; 12-week standardized behavioral intervention without additional oral drugs, including IC/BPS disease education, bladder irritant dietary restriction, timed bladder training, pelvic floor relaxation training and sleep/stress adjustment guidance. Weekly telephone follow-up to monitor adherence; no antidepressants or analgesics permitted throughout the study period.
Experimental: Arm 2 Experimental Arm (n=70); Intervention Name: Venlafaxine + Education and Behavioral Modification Program (EBMP) Intervention Description: Full identical EBMP intervention as control group, plus flexible-dose oral venlafaxine for 12 weeks. Week 1 starting dose: 75mg once daily evening administration; Week3 escalate to 150mg daily if well-tolerated; Week5 maximum titration up to 225mg daily based on individual tolerance and symptom improvement. Dose down-titration allowed for intolerable adverse events to identify individual maximum tolerated dose (MTD), maintained until week12 endpoint. No rescue analgesic, NSAID or other antidepressant allowed during study period. Weekly telephone follow-up to record drug compliance and adverse reactions.	Drug: Venlafaxine oral tablet combined with Education and Behavioral Modification Program (EBMP); Oral venlafaxine with flexible dose titration for 12 weeks plus standardized EBMP. Initial dose 75mg once daily in week 1, escalate to 150mg daily at week 3, maximum up to 225mg daily based on tolerance and symptom improvement. All participants receive identical disease education, bladder training, dietary guidance and psychological stress management training weekly. No other antidepressants, NSAIDs or rescue analgesics are allowed during the trial.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient Self-reported Global Response Assessment (GRA)	Binary clinical response endpoint, defined as significant overall improvement in bladder pain and urinary symptoms versus minimal/no improvement, completed by participants at the 12-week treatment endpoint.	12 weeks after randomization

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Visual Analog Scale (VAS) Bladder Pain Score	0-10 Likert scale; higher scores represent more severe bladder/pelvic discomfort.	Baseline, Week 1, Week2, Week6, Week12
Pelvic Pain and Urgency/Frequency (PUF) Total Score	8-item scale total score ranging 0-40; higher scores indicate worse pelvic pain and lower urinary tract symptoms.	Baseline, Week 1, Week2, Week6, Week12
O'Leary-Sant ICSI + ICPI Composite Symptom Score	ICSI (0-20) evaluates frequency, nocturia, urgency and pain; ICPI (0-16) measures symptom-related life interference.	Baseline, Week 1, Week2, Week6, Week12

Collaborators and Investigators

• Sponsor: Beijing Tiantan Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): December 31, 2026
• Primary Completion (Estimated): December 30, 2027
• Study Completion (Estimated): December 31, 2027

Study Registration Dates

• First Submitted: July 7, 2026
• First Submitted That Met QC Criteria: July 7, 2026
• First Posted (Actual): July 13, 2026

Study Record Updates

• Last Update Posted (Actual): July 13, 2026
• Last Update Submitted That Met QC Criteria: July 7, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urogenital Diseases; Male Urogenital Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urinary Bladder Diseases; Cystitis; Cystitis, Interstitial; Socioeconomic Factors; Population Characteristics; Demography; Family Characteristics; Marital Status; Educational Status; Single Person
• Other Study ID Numbers: 2026YJSKTPG

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: The plan for sharing individual participant data (IPD) has not yet been finalized. After trial completion, the research team will evaluate data sharing feasibility under the supervision of the Institutional Review Board, including assessment of participant privacy protection, data de-identification procedures, institutional data management policies and relevant domestic clinical research data regulations. A formal data sharing plan will be formulated and updated to this registry before study results publication.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No