Tamsulosin With or Without Tadalafil for Trial Without Catheter After Acute Urinary Retention Due to Benign Prostatic Hyperplasia (TAMS-TAD-TWOC)

Tamsulosin With Versus Without Tadalafil for Trial Without Catheter After Acute Urinary Retention Due to Benign Prostatic Hyperplasia: A Prospective Double-Blind Randomized Trial

Acute urinary retention is a common emergency in men with benign prostatic hyperplasia. After bladder drainage with a urethral catheter, patients usually undergo a trial without catheter to determine whether they can pass urine again without recatheterization.

This study will evaluate whether adding tadalafil 5 mg once daily to tamsulosin 0.4 mg once daily improves the chance of successful trial without catheter in men with first-episode acute urinary retention due to presumed benign prostatic hyperplasia.

Participants will be randomly assigned to receive either tamsulosin plus tadalafil or tamsulosin plus a matching placebo. Study medication will start within 24 hours after catheterization. The catheter will be removed on Day 7. If the first trial without catheter fails, the catheter will be reinserted and a second rescue trial without catheter will be performed on Day 14.

The main outcome is overall catheter-free success by Day 14. Participants will also be followed for recurrent urinary retention, post-void residual urine, urinary flow, catheter-related complications, drug-related adverse events, and the need for benign prostatic hyperplasia-related surgery within 3 months.

Study Overview

• Status: Recruiting
• Conditions: Benign Prostatic Hyperplasia; Acute Urinary Retention; Benign Prostatic Obstruction
• Intervention / Treatment: Drug: Tamsulosin; Drug: Tadalafil Placebo; Drug: Tadalafil

• Study Type: Interventional
• Enrollment (Estimated): 320
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Hany F Badawy, MD; Phone Number: +201149525028; Email: HANYFATHY86@GMAIL.COM

Study Locations

• Egypt
  • Beni Suweif Governorate
    • Banī Suwayf, Beni Suweif Governorate, Egypt, 02456
      • Recruiting
      • Department of Urology- Beni-Suef University Hospitals
      • Contact: Hany F Badawy, MD; Phone Number: +201149525028; Email: HANYFATHY86@GMAIL.COM
      • Principal Investigator: Hany F Badawy, MD
      • Contact: Email: HANYFATHY86@GMAIL.COM

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Male patient aged 50 years or older.
• First episode of spontaneous painful acute urinary retention.
• Successful urethral catheterization at presentation.
• Drained urine volume at presentation of at least 300 mL.
• Clinical impression of benign prostatic obstruction or benign prostatic hyperplasia based on history, digital rectal examination, and/or ultrasound evidence of enlarged prostate.
• Ability to provide written informed consent.

Exclusion Criteria:

• Previous episode of acute urinary retention.
• Chronic painless urinary retention phenotype.
• Active urinary tract infection or sepsis.
• Gross hematuria with clot retention.
• Suspected or known urethral stricture.
• Neurogenic bladder or major neurologic disease affecting voiding.
• History of prostate cancer or bladder cancer.
• Previous prostate surgery.
• Current use of nitrates or guanylate cyclase stimulators.
• Contraindication to tadalafil or tamsulosin.
• Severe hypotension or unstable cardiovascular disease.
• Severe renal impairment.
• Severe hepatic impairment.
• Current or recent use of phosphodiesterase type 5 inhibitors before enrollment.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Tamsulosin Plus Placebo; Participants will receive tamsulosin 0.4 mg once daily plus a matching placebo once daily. Treatment will start within 24 hours after urethral catheterization and continue until the Day-7 trial without catheter. Participants who fail the Day-7 trial without catheter will continue the assigned treatment until the rescue trial without catheter on Day 14.	Drug: Tamsulosin; Tamsulosin 0.4 mg will be administered orally once daily as open-label background therapy in both study arms. Treatment will start within 24 hours after urethral catheterization and continue until the scheduled Day-7 trial without catheter. Participants who fail the Day-7 trial without catheter will continue treatment until the rescue trial without catheter on Day 14.; Drug: Tadalafil Placebo; A matching placebo tablet will be administered orally once daily in the placebo comparator arm in addition to open-label tamsulosin 0.4 mg once daily. The placebo will be identical to tadalafil in appearance, packaging, and labeling to maintain blinding.
Experimental: Tamsulosin Plus Tadalafil; Participants will receive tamsulosin 0.4 mg once daily plus tadalafil 5 mg once daily. Treatment will start within 24 hours after urethral catheterization and continue until the Day-7 trial without catheter. Participants who fail the Day-7 trial without catheter will continue the assigned treatment until the rescue trial without catheter on Day 14.	Drug: Tamsulosin; Tamsulosin 0.4 mg will be administered orally once daily as open-label background therapy in both study arms. Treatment will start within 24 hours after urethral catheterization and continue until the scheduled Day-7 trial without catheter. Participants who fail the Day-7 trial without catheter will continue treatment until the rescue trial without catheter on Day 14.; Drug: Tadalafil; Tadalafil 5 mg will be administered orally once daily in the experimental arm in addition to open-label tamsulosin 0.4 mg once daily. Treatment will start within 24 hours after urethral catheterization and continue until the scheduled Day-7 trial without catheter. Participants who fail the Day-7 trial without catheter will continue treatment until the rescue trial without catheter on Day 14.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall Catheter-Free Success by Day 14	Proportion of participants who achieve successful spontaneous voiding after either the scheduled Day-7 trial without catheter or the rescue Day-14 trial without catheter. Success is defined as spontaneous voiding after catheter removal, voided volume of at least 100 mL, post-void residual urine less than 150 mL measured within 10-15 minutes after voiding, no recatheterization within 24 hours after the relevant trial without catheter attempt, and remaining catheter-free until Day 14 for participants who initially pass the Day-7 trial without catheter.	Day 14

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Successful Day-7 Trial Without Catheter	Proportion of participants who achieve successful spontaneous voiding after catheter removal on Day 7. Success is defined as spontaneous voiding, voided volume of at least 100 mL, post-void residual urine less than 150 mL measured within 10-15 minutes after voiding, and no recatheterization within 24 hours.	Day 7
Successful Rescue Day-14 Trial Without Catheter Among Day-7 Failures	Proportion of participants who fail the Day-7 trial without catheter and subsequently achieve successful rescue trial without catheter on Day 14 using the same predefined success criteria: spontaneous voiding, voided volume of at least 100 mL, post-void residual urine less than 150 mL measured within 10-15 minutes after voiding, and no recatheterization within 24 hours.	Day 14
Recurrent Acute Urinary Retention Within 30 Days	Proportion of participants who develop recurrent painful acute urinary retention requiring recatheterization within 30 days after randomization.	30 days
Need for Benign Prostatic Hyperplasia-Related Surgery Within 3 Months	Proportion of participants who require surgical intervention for benign prostatic hyperplasia or benign prostatic obstruction within 3 months after randomization.	3 months

Collaborators and Investigators

• Sponsor: Beni-Suef University

Study record dates

Study Major Dates

• Study Start (Actual): June 8, 2026
• Primary Completion (Estimated): November 1, 2027
• Study Completion (Estimated): December 1, 2027

Study Registration Dates

• First Submitted: June 12, 2026
• First Submitted That Met QC Criteria: June 12, 2026
• First Posted (Actual): June 17, 2026

Study Record Updates

• Last Update Posted (Actual): June 17, 2026
• Last Update Submitted That Met QC Criteria: June 12, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Benign Prostatic Hyperplasia; Tadalafil; Tamsulosin; TWOC; Trial Without Catheter
• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Genital Diseases, Male; Prostatic Diseases; Male Urogenital Diseases; Prostatic Hyperplasia; Sulfur Compounds; Organic Chemicals; Pyridines; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Hydrocarbons; Hydrocarbons, Cyclic; Hydrocarbons, Aromatic; Amides; Indoles; Benzene Derivatives; Indole Alkaloids; Benzenesulfonamides; Sulfonamides; Sulfones; Heterocyclic Compounds, 3-Ring; Carbolines; Tadalafil; Tamsulosin
• Other Study ID Numbers: BSU FMBSUREC07062026CBADAWY

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared publicly because the study includes individual-level urological and treatment-related clinical data, and participant-level data sharing is not currently included in the ethics approval or informed consent. Only aggregated, de-identified results will be reported in publications or presentations. Any future sharing of de-identified participant-level data would require additional approval from the Research Ethics Committee, Faculty of Medicine, Beni-Suef University, and an appropriate data-sharing agreement.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No