GnRH ANALOGUES

• GnRH is a decapeptide which is released in short pulses from the hypothalamus, stimulating pituitary FSH / LH production
• Continuous administration causes down-regulation of pituitary receptors, inhibiting FSH / LH production and therefore ovarian / testicular activity and inducing a menopausal state in women
• Associated with risk of osteoporosis with long-term use therefore use restricted to 6 months

Clinical use

• Pituitary desensitization prior to induction of ovulation with gonadotrophins.
• Used to treat endometriosis, fibroids and prepare the endometrium prior to hysteroscopic surgery
• Administered by intramuscular / sub dermal injection and as nasal spray
• Contraindicated in osteoporosis, pregnancy, breastfeeding

ANTI-ANDROGENS

Clinical use

• Treatment of androgenic symptoms in women with polycystic ovary syndrome (PCOS) especially hirsutism
• Anti-androgens may emasculate a male fetus therefore women must be informed of this risk and use effective contraception while on treatment

Cyproterone acetate

• Progestogenic anti-androgen
• Used in combination with ethinyloestradiol as a combined oral contraceptive to treat acne and hirsutism especially in women with Polycystic Ovary Syndrome (PCOS)
• Inhibits spermatogenesis (but is not a male contraceptive) & libido and reduces sebum production

Spironolactone

• Aldosterone antagonist with anti-androgenic effects
• Used to treat hirsutism in women with PCOS

Finasteride

• 5-alpha reductase inhibitor
• Prevents the conversion of testosterone to the active metabolite dihydrotestosterone

Flutamide

• Androgen antagonist
• Used to treat hirsutism in PCOS

Cimetidine

• Displaces testosterone from its receptor
• Used to treat hirsutism in PCOS