Gonadal Hormones: Androgens Flashcards Preview

Pharm: Final Exam Drugs > Gonadal Hormones: Androgens > Flashcards

Flashcards in Gonadal Hormones: Androgens Deck (17)
Loading flashcards...

What are the various androgens?

Testosterone: natural
Synthetic Androgens: 17 alkyl derivatives with increased anabolic effects:


DHT: dihydrotestosterone is more potent than testosterone (testis) and androstenedione (Adrenal gland). What are some functions of testosterone and DHT?

--Genitalia: development of penis, seminal vesicles, sperm, muscle mass and RBCs. Differentiation of epididymis, vas deferens, seminal vesicles. Libido and deepening of voice
DHT (dihydrotestosterone):
--differentiation of penis, scrotum and prostate
--prostate gland growth, balding and sebaceous gland activity


Testosterone via 5 alpha reductase gets converted to Dihydroxy Testosterone, what are the effects of testosterone and DHT?

Testosterone: development of penis, seminal vesicles, sperm, muscle mass and RBCs
--differentiation of epididymis, vas deferens, seminal vesicles, libido, deepening of voice, closing epiphyseal plates
DHT: early: differentiation of penis, scrotum, and prostate and late: prostate gland, growth, balding sebaceous gland activity


The drugs for androgens are what?

Androgens (Testosterone)
--receptor antagonists: flutamide
---5 alpha reductase inhibitor: Finasteride
---Synthesis inhibitors: ketoconazole
--GnRH agonists


What are the clinical uses of Androgens?

Substitution therapy in hypogonadism
Increases bone density (prevents osteoporosis), could be used in increasing muscle mass
Some cases of aplastic anemia
Admin: transdermal, buccal, subcutaneous implant and IM


What are the adverse effects of Androgens?

Over masculinization
In women: hirsutism, suppression of menses, acne and clitoral enlargement
Hepatic adenomas and prostatic hypertrophy
Cholestatic Jaundice (elevated serum transaminations)
Aggression and Dependency
Premature closure of epiphysis
illicit use in Athletes
--over dosage of androgens can result in feminization as a result of negative feedback inhibition and conversion of exogenous testosterone into estrogen


The first drug is Danazol, what does this drug do?

Is an inhibitor of P450 in gonadal steroid synthesis
Its an androgen derivative, a partial agonist of progestin and glucocorticoid receptors
Used in endometriosis and fibrocystic disease of the breast


What are AE of Danazol?

AE: hepatitis: abnormal liver function tests and drug interaction due to P450 inhibition
It is modified testosterone shows some signs of masculinizing effects: acne, hirsutism, menstrual disturbances


What are the antiandrogen drugs?

Androgen Receptor Antagonists:


What androgen receptor blockers are used for androgen receptor positive cancers?

Flutamide: a substituted anilide
Primarily used in conjunction with GnRH analogs
--Leuprolide (to decrease initial tumor flare ups of prostate cancer)


How does Spiranolactone produce antiandrogen action?

Blocks aldosterone and competes with androgen receptors
--it is used in hirsutism


How does Cyproterone produce antiandrogen action?

It has progesteronal effect suppresses LH and FSH. Used in hirsutism and to decrease excessive sexual drive in men


What is ketoconazole used for?

Adrenal and Gonadal Steroid Synthesis Inhibitor
Use: in prostate cancer but not 1st line
AE: may have drug interactions with other steroids due to decrease P450


The 5 alpha reductase inhibitor is Finasteride (Propecia), what are the uses and AE?

Inhibits conversion of testosterone to DHT
Use: BPH and promote hair growth
AE: gynecomastia, teratogenicity and impotence


How do 5 alpha reductase inhibitors work in the treatment for BPH?

Finasteride and Dutasteride: act by reducing the size of the prostate gland
--tx for 6 to 12 months is generally needed before prostate size in sufficiently reduced to improve symptoms
Side Effects: decreased libido and ejaculatory or erectile dysfunction


How do Alpha 1 adrenergic antagonists work in the treatment of BPH?

Terazosin, Doxazosin, Tamsulosin and Alfuzosin
--relieve outlet obstruction of the bladder by reducing the tension of prostatic smooth muscle in the prostate, prostate capsule, and bladder neck
AE: orthostatic hypotension and dizziness


Combination therapy with an alpha adrenergic antagonist plus a 5 alpha reductase inhibitor produces what?

Greatest reduction in the symptoms of BPH, such as acute urinary retention, urinary incontinence, renal insufficiency or recurrent urinary tract infections