Gonadal Hormones: Androgens Flashcards Preview

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

Flashcards in Gonadal Hormones: Androgens Deck (17):
1

What are the various androgens?

Testosterone: natural
Synthetic Androgens: 17 alkyl derivatives with increased anabolic effects:
Oxandrolone
Methyltestosterone
Stanozolol
Fluoxymesterone
Nandrolone
Oxymetholone
Danazol

2

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

Testosterone:
--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

3

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

4

The drugs for androgens are what?

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

5

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

6

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

7

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

8

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

9

What are the antiandrogen drugs?

Androgen Receptor Antagonists:
--Flutamide
--Bicalutamide
--Nilutamide
--Cyproterone
--Spironolactone
--Ketoconazole

10

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

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

11

How does Spiranolactone produce antiandrogen action?

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

12

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

13

What is ketoconazole used for?

Oral
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

14

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

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

15

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

16

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

17

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