Is finasteride (generic name) beneficial for males with benign prostatic hyperplasia (BPH) or at risk of developing prostate cancer?

Is Finasteride Good for Your Prostate?

Yes, finasteride is beneficial for your prostate if you have benign prostatic hyperplasia (BPH) with documented prostate enlargement greater than 30cc, as it reduces prostate volume by 15-25%, improves urinary symptoms, and significantly decreases the risk of acute urinary retention and need for surgery. 1, 2, 3

Patient Selection: Who Benefits Most

Finasteride is only effective in men with documented prostatic enlargement (prostate volume >30cc). 1, 2 The medication is ineffective and should not be used in men with lower urinary tract symptoms who do not have an enlarged prostate. 1

Ideal Candidates:

• Men with prostate volume >30cc (maximum benefit at >40cc) 2, 4
• Elevated PSA levels (≥1.5 ng/mL) 4
• Moderate to severe lower urinary tract symptoms 2
• Men seeking to prevent disease progression and avoid surgery 1, 3

Clinical Benefits for BPH

Symptom Improvement:

• Average 3-point improvement in AUA Symptom Index, which patients perceive as meaningful change 1, 2
• Symptom improvements maintained for 6-10 years in long-term studies 2, 4
• Increases peak urinary flow rate by approximately 3 ml/s 5

Disease Modification:

• Reduces risk of acute urinary retention by 67% 1, 3
• Reduces need for BPH-related surgery by 64-67% 1, 3
• Decreases prostate volume by 15-25% within 6 months 2, 4, 5
• Reduces DHT levels in prostate by approximately 70% 2, 5

Critical Timing Considerations

Finasteride has a slower onset of action compared to alpha-blockers, requiring 3-6 months before symptom improvement becomes apparent, with maximum benefit at 6-12 months. 2, 6 Patients must be counseled about this delayed response to prevent premature discontinuation. 2

Combination Therapy: Superior Outcomes

For men with enlarged prostates and moderate-to-severe symptoms, combination therapy with finasteride plus an alpha-blocker (such as tamsulosin) is superior to either medication alone. 4, 6, 3

Combination Therapy Benefits:

• 67% reduction in overall clinical progression 4, 6
• 79% reduction in acute urinary retention 4, 6
• 67% reduction in need for surgery 4, 6
• Provides both immediate symptom relief (from alpha-blocker) and long-term disease modification (from finasteride) 4

Important Safety Considerations

Sexual Side Effects:

• Decreased libido: 6.4% in first year, decreasing to 2.6% in years 2-4 2, 6
• Ejaculatory dysfunction: 3.7% in first year, decreasing to 1.5% in years 2-4 2, 6
• Erectile dysfunction: 4-15% of patients 6
• These side effects are typically reversible and become less common after the first year 1

Other Adverse Effects:

• 10% higher risk of depression claims in long-term follow-up 7
• Gynecomastia or breast tenderness may occur 2

PSA Monitoring:

• Finasteride reduces PSA levels by approximately 50% after 1 year of therapy 2, 4, 6
• The measured PSA value must be doubled after 1 year of finasteride therapy for accurate prostate cancer screening interpretation 2, 4, 6

Prostate Cancer Considerations

Chemoprevention Effects:

• Finasteride reduces overall prostate cancer detection by approximately 25% 1
• The observed increase in high-grade cancers in clinical trials is likely due to enhanced detection from smaller prostate volume (less sampling error) rather than actual tumor transformation 1
• Evidence suggests men taking finasteride had smaller, less aggressive tumors compared to placebo 1

Important Counseling Point:

Men taking finasteride for BPH should be informed about the theoretical possibility of increased high-grade prostate cancer detection, though this is likely an artifact of improved detection rather than actual increased risk. 1

FDA-Approved Indications

According to the FDA label, finasteride is indicated for: 3

• Treatment of symptomatic BPH in men with enlarged prostate
• Improvement of symptoms
• Reduction of acute urinary retention risk
• Reduction of need for surgery (TURP and prostatectomy)
• Combination with alpha-blocker doxazosin to reduce risk of symptomatic BPH progression

Finasteride is NOT approved for prevention of prostate cancer. 3

Common Pitfalls to Avoid

• Using finasteride in patients without prostatic enlargement - this is ineffective and exposes patients to unnecessary side effects 1, 2, 4
• Inadequate treatment duration - discontinuing before 6 months prevents assessment of true efficacy 2
• Failure to adjust PSA interpretation - not doubling PSA values after 1 year leads to missed prostate cancer diagnoses 2, 4
• Not counseling about delayed onset - patients expect immediate relief like with alpha-blockers 2

Treatment Algorithm

1. Confirm prostatic enlargement >30cc via imaging or digital rectal exam 2, 4
2. For moderate-to-severe symptoms with enlarged prostate: Start combination therapy with finasteride 5mg daily plus tamsulosin 0.4mg daily 4, 6
3. For mild symptoms with enlarged prostate: Consider finasteride 5mg daily monotherapy 2
4. Reassess at 6 months minimum to evaluate finasteride response 2, 4
5. Continue indefinitely for sustained disease modification and prevention of complications 6
6. Monitor PSA annually, doubling the measured value for accurate interpretation 2, 4

Long-Term Safety Profile

Long-term follow-up data (median 16 years) shows finasteride is safe with minimal non-cancer consequences beyond a modest increase in depression and reduced need for BPH procedures. 7 There is little concern about long-term adverse effects for men using finasteride for symptomatic BPH treatment. 7