What is the use of Finasteride (Propecia)?

From the Guidelines

Finasteride is primarily used to treat benign prostatic hyperplasia (BPH) and male pattern baldness, with a recommended dose of 5mg daily for BPH and 1mg daily for baldness, as it inhibits the enzyme 5-alpha-reductase, reducing dihydrotestosterone (DHT) levels and subsequently shrinking the prostate and promoting hair growth. The medication has been shown to improve urinary symptoms and reduce the risk of prostate cancer, with a study published in 1 demonstrating its effectiveness in reducing prostate size and improving symptoms. According to the study, finasteride has been found to reduce DHT levels by approximately 70%, leading to a reduction in prostate size and improvement in urinary symptoms.

The use of finasteride for BPH is supported by the American Urological Association, which recommends its use as a treatment option to reduce intraoperative bleeding and peri- or postoperative need for blood transfusion after transurethral resection of the prostate (TURP) or other surgical intervention for BPH, as stated in 1. Additionally, the medication has been found to reduce the risk of prostate cancer, with a study published in 1 demonstrating a relative risk of 0.70 for prostate cancer detection overall.

However, potential side effects of finasteride include decreased libido, erectile dysfunction, and decreased ejaculate volume, which occur in approximately 2-3% of users, as noted in the example answer. These effects typically resolve after discontinuing the medication. Women who are pregnant or may become pregnant should not handle crushed tablets due to potential risks to male fetuses. Results for hair loss typically become noticeable after 3-6 months of consistent use, with maximum benefit usually seen after about one year.

Key points to consider when prescribing finasteride include:

• The medication should be used continuously for sustained benefits, as stopping the medication will allow DHT levels to rise again
• Patients should be counseled on the potential side effects and risks associated with finasteride
• The medication is not recommended for women who are pregnant or may become pregnant
• Results for hair loss typically become noticeable after 3-6 months of consistent use, with maximum benefit usually seen after about one year
• The use of finasteride for BPH is supported by the American Urological Association, which recommends its use as a treatment option to reduce intraoperative bleeding and peri- or postoperative need for blood transfusion after TURP or other surgical intervention for BPH.

From the FDA Drug Label

The development and enlargement of the prostate gland is dependent on the potent androgen, 5α -dihydrotestosterone (DHT). Finasteride is a competitive and specific inhibitor of Type II 5α-reductase with which it slowly forms a stable enzyme complex. In patients with BPH, finasteride tablets have no effect on circulating levels of cortisol, prolactin, thyroid-stimulating hormone, or thyroxine. Adult males with genetically inherited Type II 5α -reductase deficiency also have decreased levels of DHT. Except for the associated urogenital defects present at birth, no other clinical abnormalities related to Type II 5α -reductase deficiency have been observed in these individuals These individuals have a small prostate gland throughout life and do not develop BPH In patients with BPH treated with finasteride (1 to 100 mg/day) for 7 to 10 days prior to prostatectomy, an approximate 80% lower DHT content was measured in prostatic tissue removed at surgery, compared to placebo;

The use of Finasteride (Propecia) is to treat Benign Prostatic Hyperplasia (BPH) by reducing the size of the prostate gland.

• It works by inhibiting the production of Dihydrotestosterone (DHT), a hormone that promotes the growth of prostate tissue.
• The reduction in DHT levels leads to a decrease in prostate size, which can help alleviate symptoms of BPH.
• The medication has been shown to be effective in reducing DHT levels and prostate size in patients with BPH 2.

From the Research

Use of Finasteride (Propecia)

• Finasteride, a type 2-selective 5alpha-reductase inhibitor, is used to treat men with androgenetic alopecia (male pattern hair loss) at a dose of 1 mg/day 3.
• The use of 5 mg/day finasteride (Proscar) for benign prostatic hyperplasia is known to affect serum concentrations of prostate-specific antigen (PSA), and a compensatory adjustment of the PSA concentration is recommended when screening for prostate cancer 4.
• Finasteride has been shown to reduce the incidence of prostate cancer, and its use has been considered for chemoprevention in high-risk subgroups 5.
• There is ongoing controversy surrounding the use of finasteride for androgenic alopecia due to claims of increased risk for higher grade prostate cancers, but a comprehensive review of the Prostate Cancer Prevention Trial suggests that finasteride is safe for treating androgenetic alopecia without increasing the risk of high-grade prostate cancer 6.

Potential Side Effects

• Finasteride may be associated with erectile dysfunction (ED), particularly in patients with benign prostatic hyperplasia, but the evidence is not conclusive 7.
• Some studies have reported side effects of finasteride associated with sexual dysfunction, including ED, male infertility, ejaculation problems, and loss of libido, even in patients with male androgenetic alopecia 7.
• Physicians should discuss possible long-term effects of finasteride on sexual function with their patients, although the relationship between finasteride and ED is not fully understood 7.