Steroid Synthesis Inhibitors

• Inhibitor of adrenal & gonadal steroid synthesis w/o affecting ovarian aromatase but reduces human placental aromatase activity

• Displaces estradiol and dihydrotestosterone from sex hormone binding protein in vitro and increases the estradiol:testosterone ratio

Steroid Synthesis Inhibitors

Adverse Effects:

• Reversible Gynecomastia due to increase in estradiol: testosterone ratio

• Not useful in women with increased androgen levels because of associated toxicity with prolonged use of the required dose

Streoid Precursors to Androgens Inhibitors

• 17α-hydroxylase inhibitor

• For metastatic prostate CA

Streoid Precursors to Androgens Inhibitors

• 5α-reductase inhibitor

• For reduction of prostate size in men with BPH

• For hirsutism in women

• For early male pattern baldness in men

Steroid Precursors to Androgens Inhibitors

• Orally active enzyme inhibitor that decreases dihydrotestosterone levels

• Effect starts within 8 hours and lasts after 24 hrs

• Excreted in feces

• Not approved for use in women or children

Steroid Precursors to Androgens Inhibitors

• For treatment of BPH

• Orally active steroid derivative with a slow onset of action and much longer half-life

• Not approved for use in women or children

Receptor Inhibitors

• For management of prostatic carcinoma who have not had prior endocrine therapy

• May be useful in managing excessive androgen synthesis in women

Receptor Inhibitors

• Although not a steroid, it behaves like a competitive antagonist at the androgen receptor

• Often causes mild gynecomastia & mild reversible hepatic toxicity

Receptor Inhibitors

• Management of metastatic carcinoma of the prostate

• Potent orally active antiandrogens that can be administered as a single daily dose

Receptor Inhibitors

• Tumor flare reduction; fewer GI effects than flutamide

• +GnRH analog

Receptor Inhibitors

• Used following surgical castration

Receptor Inhibitors

• For reduction of sexual drive in men

• Inhibit action of androgens at target organ

• Acetate form has notable pro-gestational effect that suppresses feedback enhancement of LH/FSH

• Further improves antiandrogen effect

Receptor Inhibitors

• For treatment of hirsutism in women

• Aldosterone competitive inhibitor

• Competes with dihydrotestosterone for androgen receptors

• Reduces 17-α hydroxylase activity, decreasing plasma testosterone and androstenedione levels

Contraception in Men

Chemical Contraception

• Produces azoospermia

• Minor toxicity: Gynecomastia, acne

Contraception in Men

Chemical Contraception

• Well tolerated but no more effective than testosterone alone

Contraception in Men

Chemical Contraception

• No more effective than testosterone

Contraception in Men

Chemical Contraception

• Produces azoospermia in 94% of men when taken daily

Contraception in Men

Chemical Contraception

• Cottonseed derivative (Chinese study)

• Destroys elements of the seminiferous epithelium but does not alter the endocrine function of the testis

• Major adverse effect: hypokalemia (transient paralysis)

• Abandoned as a candidate male contraceptive

Contraception in Men

Testosterone or 5a-dihydrotestosterone

• _______ HDL levels and _______ LDL levels

Contraception in Men

Testosterone or 5a-dihydrotestosterone

• More pronounced in women and children than in normal men