RecruitingPhase 4Drug trialTamsulosin Dose Escalation or Silodosin Switch Before Trial Without Catheter in BPH-Related Acute Urinary RetentionThis randomized controlled trial will compare three medication strategies before trial without catheter in men with acute urinary retention due to benign prostatic hyperplasia who were already taking tamsulosin 0.4 mg once daily before the retention episode. After urethral catheterization, eligible participants will be randomly assigned to one of three groups for 7 days: continuation of tamsulosin 0.4 mg once daily, escalation to tamsulosin 0.8 mg once daily, or switching to silodosin 8 mg once daily. The urethral catheter will be removed on Day 7, and the ability to void successfully without re-catheterization will be assessed. Follow-up will continue to Day 30, with additional recording of catheter-free status, recurrent urinary retention, urinary flow, post-void residual urine, symptom scores, adverse drug events, catheter-related complications, and the need for later benign prostatic hyperplasia-related surgery.