Finasteride [For B.P.H.]

Approved Medical Use:

• Benign Prostatic Hyperplasia (BPH):
• Treatment of symptomatic BPH in men with an enlarged prostate.
• Improves urinary flow and reduces symptoms such as weak stream, urgency, and nocturia.
• Lowers the risk of acute urinary retention (AUR).
• Decreases the likelihood of the need for BPH-related surgery (e.g., TURP or prostatectomy).

Off-label but Clinically Accepted Uses:

• Prevention of BPH Progression in patients with mild to moderate enlargement.
• Chronic Prostatitis / Chronic Pelvic Pain Syndrome (CP/CPPS) — in selected cases where prostate-related inflammation is involved.

Note: This profile strictly focuses on Finasteride’s role in BPH, not in androgenic alopecia or other uses.

Adults (Male):

• Usual Dose: 5 mg orally once daily.
• Administration: With or without food.
• Onset of action: Symptom improvement may be observed after 3 months; full effect may take up to 6–12 months.
• Duration: Long-term use is typically necessary for sustained benefit.

Elderly Patients:

• No dosage adjustment required. Well tolerated in geriatric patients, even with mild to moderate systemic comorbidities.

Renal Impairment:

• No dose adjustment necessary. Finasteride pharmacokinetics are not significantly affected.

Hepatic Impairment:

• Use with caution due to hepatic metabolism. Clinical safety in hepatic dysfunction has not been fully established.

Special Handling Instructions:

• Tablets should not be broken or crushed.
• Avoid handling broken tablets if pregnant or potentially pregnant (risk of fetal harm).

Finasteride selectively inhibits the Type II 5-alpha-reductase enzyme, which converts testosterone into dihydrotestosterone (DHT) — the primary androgen responsible for prostate enlargement. By lowering intraprostatic and circulating DHT levels, Finasteride reduces the size of the prostate gland, alleviates bladder outlet obstruction, and improves urinary flow. Its mechanism is androgen-suppressive, leading to a decrease in epithelial cell proliferation and prostate volume over time.

• Absorption: Rapidly absorbed after oral administration; bioavailability ≈ 80%.
• Distribution: Widely distributed; plasma protein binding ~90%.
• Metabolism: Extensively metabolized in the liver via CYP3A4 into two metabolites with minimal additional activity.
• Elimination Half-life: Approximately 5–6 hours in younger men; up to 8 hours in elderly.
• Excretion: Primarily excreted in feces (≈57%) and urine (≈39%).

• Pregnancy:
  Category X — Contraindicated.
  Finasteride can cause external genital abnormalities in a male fetus. Women who are or may become pregnant must not handle crushed or broken tablets due to risk of transdermal absorption.
• Lactation:
  Not approved for use in women. It is unknown if Finasteride is excreted in breast milk. Should not be used during breastfeeding.
• General Warning:
  Not intended for use in any female population.

• Class: 5-Alpha Reductase Inhibitor
• Subclass: Type II selective inhibitor
• Therapeutic Area: Urology / Men’s Health

• Known hypersensitivity to Finasteride or its excipients
• Use in women (particularly during pregnancy or breastfeeding)
• Use in children or adolescents
• Presence of prostate cancer without adequate evaluation (Finasteride lowers PSA and may mask cancer)

• Prostate Cancer Risk:
  May increase the incidence of high-grade prostate cancer (Gleason score ≥8). Regular PSA monitoring is necessary. Finasteride decreases PSA levels by ~50% after 6 months of therapy.
• Psychiatric Effects:
  Depression, mood alterations, and suicidal ideation have been reported. Patients should be monitored for new or worsening mental health symptoms.
• Sexual Side Effects:
  Persistent erectile dysfunction, reduced libido, and ejaculation disorders may occur and, in rare cases, continue after discontinuation (post-finasteride syndrome).
• Breast Effects in Men:
  Breast tenderness, enlargement, and rarely, male breast cancer have been reported. Prompt investigation of breast symptoms is essential.
• Liver Disease:
  Use with caution in hepatic impairment due to hepatic metabolism.

Common Adverse Effects (≥1%):

• Reproductive System:
• Erectile dysfunction
• Decreased libido
• Ejaculation disorder (e.g., reduced volume)
• Breasts:
• Gynecomastia
• Breast tenderness
• General:
• Rash
• Dizziness

Uncommon to Rare Side Effects:

• Persistent sexual dysfunction after discontinuation
• Depression and suicidal thoughts
• Hypersensitivity reactions (pruritus, swelling, urticaria)
• Testicular pain
• Male breast cancer (extremely rare)

Most side effects resolve with continued use or after discontinuation; some may persist in rare cases.

Enzyme Considerations:

• Metabolized via CYP3A4, but does not significantly inhibit or induce this enzyme.

Drug-Drug Interactions:

• No clinically significant interactions identified with commonly used drugs (e.g., antihypertensives, statins).
• CYP3A4 Inducers (e.g., rifampin): May reduce Finasteride plasma levels; clinical relevance minimal.
• Androgenic agents or testosterone therapy: May counteract the therapeutic effects of Finasteride.

Drug-Food/Alcohol Interactions:

• No known interactions with food or alcohol.

Lab Interference:

• Finasteride reduces PSA levels by ~50%. Clinicians should adjust PSA interpretation accordingly when screening for prostate cancer.

• FDA Label Update:
  Included warnings about potential for persistent sexual side effects and depression.
• MHRA (UK) Advisory:
  Recommends enhanced patient counseling on the potential for psychological and sexual side effects.
• AUA Clinical Guidelines:
  Recommends Finasteride for men with moderate-to-severe BPH and prostates >40 mL. Also supports combination therapy with alpha-blockers for greater symptom relief.
• Post-Finasteride Syndrome (PFS):
  Recognized as a potential, though rare, complication. Further research ongoing.

• Recommended Temperature: Store below 30°C (86°F)
• Protection from Light and Moisture: Keep in original packaging until use.
• Do Not Crush or Break Tablets: Especially important to prevent accidental exposure in women.
• Disposal Instructions: Unused or expired tablets should be disposed of in accordance with local pharmaceutical waste regulations.