Nonsteroidal competitive inhibition at androgen receptors (decreases steroid binding).
Indications:
Metastatic prostate cancer (often in combination with GnRH analogs for medical castration).
Hirsutism (e.g., in Polycystic Ovary Syndrome - PCOS).
Androgenetic alopecia in female individuals.
Adverse Effects:
Gynecomastia.
Hypogonadism in males.
Hepatotoxicity (particularly noted with Flutamide, requires monitoring).
Cyproterone
Mechanism of Action:
Blocks androgen receptor.
Has progesterone-like effects.
Indications:
Prostate cancer.
Hirsutism.
Precocious puberty.
Hypersexuality.
Adverse Effects:
(Note: Specific adverse effects for Cyproterone were not listed separately in the provided text excerpt, but common antiandrogen effects like gynecomastia and potential progestogenic effects/mood changes can occur).
Spironolactone
Mechanism of Action:
Blocks androgen receptor.
Inhibits 17,20-desmolase and 17 alpha-hydroxylase (steroid synthesis enzymes).
Inhibits 5-alpha reductase enzyme.
Indications:
Androgenic effects of PCOS (e.g., hirsutism).
Androgenetic alopecia in female individuals.
(Also used commonly as a diuretic/for heart failure/hypertension due to its mineralocorticoid receptor antagonist activity, though not listed in this context).
Adverse Effects:
Gynecomastia.
Breast tenderness.
Amenorrhea.
(Hyperkalemia is a significant risk due to its primary mineralocorticoid antagonist effect).
Ketoconazole
Mechanism of Action:
Inhibits several steps of adrenal and gonadal steroid synthesis (e.g., 17,20-desmolase, 17 alpha-hydroxylase, 11β-hydroxylase, cholesterol side-chain cleavage).
Indications:
Androgenic effects of PCOS (e.g., hirsutism) - (Use is limited due to toxicity).
