Mechanism of action

Finasteride is an inhibitor of 5 alpha-reductase, an enzyme which metabolises testosterone into dihydrotestosterone.

Indications

  • Benign prostatic hyperplasia
  • Male-pattern baldness

Adverse effects

  • Impotence
  • Decrease libido
  • Ejaculation disorders
  • Gynaecomastia and breast tenderness

Monitoring

Finasteride causes decreased levels of serum prostate-specific antigen