What is the comparison between finasteride (a 5-alpha-reductase inhibitor) and tamsulosin (an alpha-1 adrenergic receptor blocker) in terms of their use?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: April 17, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Finasteride should be considered over tamsulosin for the treatment of benign prostatic hyperplasia (BPH) in patients with a prostate volume greater than 30cc or a PSA level greater than 1.5ng/mL, as it addresses the underlying cause of the condition and can prevent disease progression, as recommended by the AUA guideline 1. When deciding between finasteride and tamsulosin, it's essential to consider the patient's prostate size, symptom severity, and treatment goals. Finasteride, a 5-alpha-reductase inhibitor (5-ARI), reduces prostate size by blocking the conversion of testosterone to dihydrotestosterone (DHT), leading to a decrease in prostate volume and an improvement in symptoms over time 1.

  • Key differences between finasteride and tamsulosin include:
    • Onset of action: Tamsulosin works quickly, providing relief from urinary symptoms within days to weeks, while finasteride takes 3-6 months to show full effects.
    • Mechanism of action: Tamsulosin relaxes prostate and bladder neck muscles, while finasteride shrinks the prostate gland.
    • Side effects: Tamsulosin may cause dizziness, retrograde ejaculation, and orthostatic hypotension, while finasteride can cause sexual dysfunction, reduced libido, and requires PSA monitoring.
  • The AUA guideline recommends combination therapy with an alpha-blocker (such as tamsulosin) and a 5-ARI (such as finasteride) for patients with LUTS associated with demonstrable prostatic enlargement, as judged by a prostate volume of >30cc on imaging, a PSA >1.5ng/mL, or palpable prostate enlargement on DRE 1.
  • Studies have shown that finasteride can reduce the risk of clinical progression, including acute urinary retention and the need for surgical intervention, in men with BPH 1.
  • It's crucial to counsel patients on the slower symptom improvement with finasteride and the importance of regular follow-up and PSA monitoring to assess treatment efficacy and potential side effects 1.

From the Research

Comparison of Finasteride and Tamsulosin

  • Finasteride and tamsulosin are two different types of medications used to treat benign prostatic hyperplasia (BPH) symptoms 2, 3, 4, 5, 6.
  • Finasteride is a 5-alpha reductase inhibitor that reduces prostate size, while tamsulosin is an alpha 1-adrenergic receptor antagonist that relaxes the muscles in the prostate and bladder neck 3, 4, 6.

Efficacy of Finasteride and Tamsulosin

  • Finasteride has been shown to improve urinary symptom scores and reduce the risk of BPH progression, but its effectiveness may take 6-12 months to achieve maximum benefits 3, 4.
  • Tamsulosin has been shown to improve urinary symptoms and quality of life, with a faster onset of action compared to finasteride 2, 3, 5.
  • Combination therapy with finasteride and tamsulosin may provide additional benefits in improving urinary symptoms and reducing the risk of BPH progression 2, 5.

Comparison of Finasteride and Tamsulosin in Clinical Trials

  • A study comparing finasteride and tamsulosin found that both medications improved urinary symptoms, but finasteride was associated with a lower risk of surgical intervention 4.
  • Another study found that combination therapy with tadalafil and finasteride improved urinary and sexual outcomes, while combination therapy with tamsulosin and finasteride provided better average flow rates 5.
  • A review of clinical trials found that finasteride and tamsulosin were both effective in improving BPH symptoms, but finasteride may have a slower onset of action and more side effects 3, 4, 6.

Side Effects and Safety

  • Finasteride has been associated with side effects such as impotence, erectile dysfunction, decreased libido, and ejaculation disorder 4, 5.
  • Tamsulosin has been associated with side effects such as dizziness, postural hypotension, and asthenia, but these side effects are generally less common than with finasteride 3, 4, 6.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Finasteride for benign prostatic hyperplasia.

The Cochrane database of systematic reviews, 2010

Research

[Drugs for the treatment of benign prostatic hypertrophy].

Minerva urologica e nefrologica = The Italian journal of urology and nephrology, 2000

Related Questions

What is the use of Flomax (Tamsulosin)?
What is the best procedure for Benign Prostatic Hyperplasia (BPH)?
What is the role of alpha-1 adrenergic (alpha-1 adrenergic) blockers in the treatment of benign prostatic hyperplasia (BPH)?
What is the clinical significance of a 65-year-old male's elevated Prostate-Specific Antigen (PSA) level of 5.0, with a history of high-grade bladder Transitional Cell Carcinoma (TCC), Benign Prostatic Hyperplasia (BPH), and recent Computed Tomography (CT) scan showing prostatomegaly with bladder outlet obstruction?
What is the best initial medication for Benign Prostatic Hyperplasia (BPH)?
What does having very dark venous blood during phlebotomy (blood draw) indicate?
What would a pleural effusion on the left side typically present with on the left chest: decreased breath sounds, egophony, whispered pectoriloquy, crackles, or hyperresonance?
What are the treatment options for Non-Alcoholic Fatty Liver Disease (NAFLD)?
What are the methods for preventing anemia in preconception (before pregnancy)?
What is the significance of a 40-year-old female with hypoferritinemia (Iron 37 mcg/dL), elevated Total Iron-Binding Capacity (TIBC) (445 mcg/dL), and low Iron Saturation (17%)?
What is the most likely diagnosis for a patient with right-sided chest pain, dyspnea (difficulty breathing) on exertion, significant weight loss, fullness to percussion, decreased breath sounds, pleural thickening, and right-sided pleural effusion, with differential diagnoses including mesothelioma, small cell lung cancer, adenocarcinoma, and large cell lung cancer?

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.