Finasteride

1. Introduction

Finasteride is a 5-alpha-reductase inhibitor used to treat conditions caused by excessive production of dihydrotestosterone (DHT), such as benign prostatic hyperplasia (BPH) and androgenetic alopecia (male pattern hair loss). By reducing DHT levels, it helps alleviate urinary symptoms in BPH and promotes hair regrowth in men.

2. Indications

  • Approved Indications:
    • Benign prostatic hyperplasia (BPH) to improve symptoms and reduce the risk of urinary retention or need for surgery.
    • Androgenetic alopecia (male pattern baldness) in men.
  • Off-Label Uses:
    • Hirsutism in women (under close medical supervision).

3. Dosage

  • Adults:
    • BPH: 5 mg orally once daily.
    • Androgenetic Alopecia: 1 mg orally once daily.
  • Children:
    • Not recommended for use in children.
  • Elderly:
    • No specific dose adjustment required, but consider comorbid conditions.

4. Administration

  • Take orally with or without food, at the same time each day.
  • Swallow the tablet whole; do not crush or chew.

5. Forms Available

  • Tablets: 1 mg, 5 mg.

6. Side Effects

6.1. Common Side Effects

  • Reduced libido.
  • Erectile dysfunction.
  • Ejaculation disorders.

6.2. Less Common Side Effects

  • Breast tenderness or enlargement (gynecomastia).
  • Skin rash.

6.3. Rare but Serious Side Effects

  • Depression or mood changes.
  • Male breast cancer (very rare).
  • Severe allergic reactions (e.g., angioedema).

7. Warnings

  • Pregnancy Warning: Women who are pregnant or may become pregnant must avoid handling broken or crushed tablets, as finasteride can cause genital abnormalities in male foetuses.
  • Prostate Cancer Risk: Finasteride may reduce the overall risk of prostate cancer but may increase the likelihood of developing high-grade prostate cancer.

8. Precautions

  • Use cautiously in patients with liver impairment, as finasteride is extensively metabolised in the liver.
  • Regularly monitor prostate-specific antigen (PSA) levels, as finasteride can lower PSA, potentially masking prostate cancer.

9. Interactions

  • Drug-Drug Interactions:
    • No significant drug interactions are reported, but use cautiously with drugs affecting liver enzymes.
  • Drug-Food Interactions:
    • No significant food interactions.

10. Monitoring Parameters

  • Symptom improvement in BPH or hair regrowth in androgenetic alopecia.
  • PSA levels in men being monitored for prostate cancer.
  • Monitor for side effects such as depression or breast tenderness.

11. Use in Children

  • Not recommended for use in children or adolescents due to lack of safety and efficacy data.

12. Use in Pregnancy

  • Category X: Contraindicated in women who are pregnant or may become pregnant. Finasteride can cause severe foetal harm if absorbed through the skin or ingested.

13. Use in Elderly

  • Generally safe for elderly patients, with no specific dose adjustments required. Monitor for age-related conditions.

14. Use in Kidney Disease

  • No dose adjustment is required in patients with renal impairment.

15. Use in Liver Disease

  • Use cautiously in patients with hepatic impairment, as finasteride is metabolised in the liver.

16. Patient Counselling Points

  • Take finasteride daily as prescribed, even if you do not notice immediate results. Hair regrowth or symptom improvement may take 3–6 months.
  • Do not stop taking finasteride without consulting your doctor, as stopping can reverse its effects.
  • Women who are pregnant or planning to conceive should avoid handling crushed or broken tablets.
  • Report any persistent side effects, such as mood changes, breast tenderness, or sexual dysfunction, to your doctor.
  • Regular follow-ups are essential to monitor PSA levels and assess treatment effectiveness.

17. Table of Brand Names, Manufacturers, and Prices

Brand NameManufacturerPrice (USD)
Proscar (5 mg)Merck & Co.$70–100 (30 tablets)
Propecia (1 mg)Merck & Co.$80–120 (30 tablets)
Generic FinasterideVarious$10–40 (30 tablets)

18. FAQs (15 Questions)

  1. What is finasteride used for?
    Finasteride is used to treat benign prostatic hyperplasia (BPH) and male pattern hair loss.
  2. How does finasteride work?
    It inhibits 5-alpha-reductase, reducing dihydrotestosterone (DHT) levels, which are involved in prostate growth and hair loss.
  3. How long does it take for finasteride to work?
    Symptom improvement for BPH may be seen in 3–6 months, while hair regrowth may take 6–12 months.
  4. Can finasteride be taken by women?
    Finasteride is not recommended for women and is contraindicated in pregnant women due to the risk of severe foetal harm.
  5. What are the common side effects of finasteride?
    Common side effects include reduced libido, erectile dysfunction, and ejaculation disorders.
  6. Can finasteride cause depression?
    Yes, mood changes, including depression, have been reported. Consult your doctor if these occur.
  7. Can I stop taking finasteride once I see improvement?
    No, stopping finasteride can reverse its effects. Continue treatment as prescribed.
  8. Is finasteride safe for elderly men?
    Yes, it is generally safe, but PSA monitoring and side effect assessments are recommended.
  9. Does finasteride interact with other medications?
    Finasteride has minimal interactions but should be used cautiously with drugs affecting liver enzymes.
  10. How should finasteride be stored?
    Store at room temperature, away from moisture and heat.
  11. Can finasteride treat all types of hair loss?
    No, it is effective only for androgenetic alopecia and not for other causes of hair loss.
  12. Can finasteride prevent prostate cancer?
    It may reduce the risk of low-grade prostate cancer but can increase the likelihood of high-grade prostate cancer.
  13. What should I do if I miss a dose of finasteride?
    Take it as soon as you remember, but skip it if it’s close to the next dose. Do not double up.
  14. Can I drink alcohol while taking finasteride?
    Yes, but excessive alcohol consumption should be avoided to prevent additional strain on the liver.
  15. How should women handle finasteride tablets?
    Women who are pregnant or may become pregnant should avoid handling broken or crushed tablets to prevent absorption.