Tamsulosin With or Without Tadalafil for Trial Without Catheter After Acute Urinary Retention Due to Benign Prostatic Hyperplasia

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.