Is finasteride suitable for treatment?

From the Guidelines

Finasteride is a suitable treatment option for patients with benign prostatic hyperplasia (BPH) who have an enlarged prostate, as it can reduce the size of the prostate, increase peak urinary flow rate, and reduce BPH symptoms. The medication works by inhibiting the enzyme 5-alpha reductase, which converts testosterone to dihydrotestosterone (DHT), a hormone that contributes to prostate enlargement 1. According to the American Society of Clinical Oncology/American Urological Association 2008 clinical practice guideline, finasteride demonstrates both efficacy and acceptable safety for the treatment of lower urinary tract symptoms (LUTS) due to BPH, with an average patient experiencing a 3-point improvement in the AUA Symptom Index 1.

Key Considerations

• Finasteride is not appropriate for men with LUTS who do not have any prostatic enlargement, as it is ineffective for relief of lower urinary tract obstructive symptoms in these patients 1.
• The medication can reduce the risk of subsequent acute urinary retention and the need for BPH-related surgery, with the absolute benefit increasing with rising prostate volume or serum PSA 1.
• Potential side effects of finasteride include decreased libido, erectile dysfunction, and decreased ejaculate volume in a small percentage of users, which are reversible and uncommon after the first year of therapy 1.
• Regular follow-up with a healthcare provider is recommended to monitor effectiveness and any adverse effects.

Treatment Guidelines

• The American Urological Association (AUA) guideline on the management of BPH recommends finasteride as a treatment option for patients with moderate to severe symptoms of BPH, along with other medical therapies such as alpha-adrenergic blockers and combination therapy 1.
• The guideline also recommends that patients with a history of microscopic or gross hematuria, urethral stricture, or prior lower urinary tract surgery undergo additional diagnostic tests, such as urethrocystoscopy and ultrasound, to guide the choice of therapy 1.

From the FDA Drug Label

1.1 Monotherapy Finasteride tablets are indicated for the treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate to:

• Improve symptoms
• Reduce the risk of acute urinary retention
• Reduce the risk of the need for surgery including transurethral resection of the prostate (TURP) and prostatectomy.

Finasteride is suitable for the treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate. The primary uses of finasteride include improving symptoms, reducing the risk of acute urinary retention, and reducing the need for surgical interventions such as TURP and prostatectomy 2.

• Key Indications:
  • Improve symptoms of BPH
  • Reduce risk of acute urinary retention
  • Reduce need for surgery (TURP, prostatectomy)
• Important Considerations:
  • Finasteride is not approved for the prevention of prostate cancer 2.
  • There is an increased risk of high-grade prostate cancer with finasteride use, as observed in the PCPT trial 2 and 2.

From the Research

Finasteride Suitability for Treatment

• Finasteride is a specific and competitive inhibitor of 5alpha-reductase enzyme Type 2, which inhibits the conversion of testosterone to dihydrotestosterone (DHT) 3.
• The FDA-approved dermatological indication of finasteride is androgenetic alopecia, but it is also used to treat benign prostatic hyperplasia (BPH) 4.
• Studies have shown that finasteride can improve peak urinary flow rate and urological symptoms in men with symptomatic BPH, with benefits maintained in the medium term (up to 2 years) 4, 5.
• However, finasteride has been associated with sexual dysfunction, including decreased libido, ejaculation disorders, and impotence, although these adverse events occur in only a small proportion (about 2 to 3%) of patients 3, 4.

Efficacy and Safety

• Finasteride has been shown to be effective in reducing the incidence of low-grade prostate cancer, but its impact on high-grade prostate cancer is still a topic of debate 3, 6.
• Long-term studies have demonstrated that finasteride can maintain efficacy in at least 30% of patients with BPH, with an excellent safety profile 5.
• The use of finasteride for androgenetic alopecia has been controversial due to concerns about the risk of high-grade prostate cancer, but a comprehensive review of the Prostate Cancer Prevention Trial (PCPT) suggests that finasteride is a safe treatment for androgenetic alopecia without increasing the risk of high-grade prostate cancer 6.

Treatment Considerations

• Physicians should discuss possible long-term effects of finasteride on sexual function with their patients, although the evidence does not show that adverse events of sexual dysfunction are absolutely associated with 5α-RIs 7.
• A trial period of 6 or possibly 12 months is necessary to assess patient responsiveness to finasteride, as the benefits of therapy may not become apparent until completion of at least 6 months of therapy 4.
• Thorough pretreatment assessment and periodic follow-up examinations for malignancy are required in clinical practice when using finasteride to treat BPH 4.