Can Prostina (finasteride) tablets reduce prostate size in a middle-aged or older male patient with Benign Prostatic Hyperplasia (BPH)?

Can Prostina Tablets Reduce Prostate Size?

If "Prostina" refers to finasteride (a 5-alpha-reductase inhibitor), then yes, it reduces prostate size by 15-25% within 6 months; however, if "Prostina" refers to the herbal formulation studied in the 2005 trial, there is no evidence it reduces prostate size—it only provides symptomatic relief comparable to terazosin without affecting the underlying prostate enlargement. 1, 2, 3

Understanding the Two Different "Prostina" Products

Finasteride (If This Is What You Mean by "Prostina")

Finasteride definitively reduces prostate volume by 15-25% after 6 months of continuous therapy through inhibition of 5-alpha-reductase type II, which reduces dihydrotestosterone (DHT) in prostatic tissue by approximately 70%. 1, 2

• This prostate size reduction is sustained long-term, with studies demonstrating maintained effects for 6-10 years 1, 2
• The mechanism directly addresses the pathophysiology of benign prostatic hyperplasia by blocking the conversion of testosterone to DHT, the primary androgen driving prostate growth 4, 5
• Prostate-specific antigen (PSA) levels decrease by approximately 50% after 1 year of therapy, which must be accounted for when screening for prostate cancer by doubling the measured PSA value 6, 1, 2

Herbal "Prostina" Formulation (Multi-Ingredient Capsule)

The herbal Prostina product studied in 2005 showed no evidence of reducing prostate size—it only provided symptomatic relief measured by AUA symptom scores, similar to how alpha-blockers work without affecting the underlying prostate enlargement. 3

• The 2005 study compared this herbal formulation to terazosin (an alpha-blocker) and measured only urodynamic parameters and symptom scores, not actual prostate volume reduction 3
• Alpha-blockers like terazosin relax smooth muscle but do not shrink the prostate or prevent disease progression (acute urinary retention, need for surgery) 7, 8, 9

Who Benefits Most from Finasteride (If Using the 5-ARI)

Finasteride is most effective in men with documented prostatic enlargement greater than 30cc, and provides minimal benefit in men without enlarged prostates. 1, 2

• Men with larger prostates (≥40cc) and/or higher PSA values (≥1.5 ng/mL) derive the greatest benefit due to higher baseline risk of disease progression 6, 1
• Using finasteride in patients without prostatic enlargement is ineffective and exposes them to unnecessary side effects 1, 2

Timeline for Prostate Size Reduction

Prostate volume reduction with finasteride occurs gradually, with maximum shrinkage achieved by 6 months, though symptom improvement may take 3-6 months to become clinically apparent. 6, 1, 2

• This slower onset contrasts with alpha-blockers, which provide rapid symptom relief within 3-5 days but do not reduce prostate size 8, 9
• Patients should be counseled that finasteride requires at least 3-6 months for adequate assessment of treatment success 7, 1

Long-Term Benefits Beyond Size Reduction

Beyond reducing prostate volume, finasteride significantly reduces the risk of acute urinary retention by 67-79% and the need for BPH-related surgery by 67%, making it a disease-modifying therapy rather than just symptomatic treatment. 6, 1, 4, 9

• These preventive effects are most pronounced in men with enlarged prostates who are at greatest risk of disease progression 4, 9
• Long-term efficacy has been demonstrated for more than 7 years of continuous therapy 7, 5

Important Side Effects to Discuss

Sexual dysfunction occurs in approximately 6-10% of patients during the first year, including decreased libido (6.4%), ejaculatory dysfunction (3.7%), and erectile dysfunction, though these rates typically decrease after the first year to 2.6% and 1.5% respectively. 1, 2, 9

• The FDA has amended finasteride labels to include warnings about persistent sexual dysfunction that may continue after drug discontinuation in a small subset of patients 1
• Other side effects include gynecomastia in approximately 0.4% of patients 5

Critical Pitfall to Avoid

Failing to adjust PSA interpretation is a major clinical error—after 1 year of finasteride therapy, the measured PSA value must be doubled to accurately screen for prostate cancer, as finasteride reduces PSA by approximately 50%. 6, 1, 2

• Rising PSA while on finasteride (even after adjustment) warrants urologic referral for possible prostate cancer evaluation 8