Effect of Different Dosing Regimens of Tadalafil or Tamsulosin Combined With 5α-Reductase Inhibitors on Urinary and Sexual Outcomes in Benign Prostatic Hyperplasia

Benign prostatic hyperplasia (BPH) is one of the most common causes of lower urinary tract symptoms (LUTS) in older men and is frequently associated with impaired sexual function. Alpha-blockers and 5-alpha reductase inhibitors (5ARIs) are widely used for medical management; however, both treatment strategies may adversely affect sexual function. Phosphodiesterase type-5 inhibitors, particularly tadalafil, have emerged as an alternative therapeutic option because they improve LUTS while preserving erectile function.

This randomized, single-blind, controlled clinical trial was conducted at the Department of Urology, Faculty of Medicine, Beni-Suef University, Egypt. The study enrolled 240 eligible men aged 50 years or older with moderate-to-severe LUTS secondary to BPH and prostate volume greater than 40 mL. Participants were randomly allocated into six equal treatment groups comparing different dosing regimens of tadalafil or tamsulosin combined with 5-alpha reductase inhibitors.

The primary objective was to compare improvements in lower urinary tract symptoms using the International Prostate Symptom Score (IPSS). Secondary objectives included evaluation of erectile function using the International Index of Erectile Function-Erectile Function domain (IIEF-EF), ejaculatory function using the Male Sexual Health Questionnaire-Ejaculatory Dysfunction (MSHQ-EjD), maximum urinary flow rate (Qmax), prostate volume, prostate-specific antigen (PSA), post-void residual urine volume (PVR), and treatment-related adverse events.

Participants received treatment for 12 weeks and were assessed at baseline and at the end of the study. Safety was evaluated by monitoring adverse events throughout the study. The findings are expected to identify the most effective and well-tolerated combination regimen for improving both urinary and sexual outcomes in men with benign prostatic hyperplasia.

Inclusion criteria

• Male participants aged 50 years or older.
• Newly diagnosed with benign prostatic hyperplasia (BPH).
• Moderate to severe lower urinary tract symptoms (LUTS), defined as International Prostate Symptom Score (IPSS) > 7.
• Prostate volume >40 mL confirmed by transrectal ultrasonography (TRUS).
• Sexually active with a baseline International Index of Erectile Function-Erectile Function (IIEF-EF) score >10.
• Prostate-specific antigen (PSA) <4 ng/mL and no suspicious findings on digital rectal examination (DRE).
• Able and willing to provide written informed consent.

Exclusion criteria

• History of prostate cancer.
• Previous prostate surgery.
• Abnormal digital rectal examination suggestive of malignancy.
• Severe erectile dysfunction (IIEF-EF score ≤10).
• Uncontrolled diabetes mellitus.
• Uncontrolled cardiovascular disease.
• Neurological disorders affecting bladder function.
• Renal impairment.
• Hepatic impairment.
• Active urinary tract infection.
• Bladder stones or other significant urological pathology.
• Known hypersensitivity to tamsulosin, tadalafil, or 5-alpha reductase inhibitors.
• Patients actively seeking fertility treatment.
• Current use of medications known to significantly affect sexual function.
• Concurrent use of nitrates or contraindicated antihypertensive medications.