Androgens

Question 1

Spermatogenesis requires help from

Answer 1

Testosterone from Leydig Cells (via LH stimulation)

FSH from pituitary

Question 2

Testosterone is the most important androgen in muscle and liver

Answer 2

:)

Question 3

T is converted to dihydrotestosterone by

Answer 3

5-alpha-reductase. two different types
1 - non-genital skin, liver, and bone
2 - urogenital tissue

Question 4

Dihydrotestosterone converted to estrogen by

Answer 4

CYP19 aromatase in peripheral tissue

Question 5

Testosterone MOA

Answer 5

binds cytosolic receptors to ultimately alter target gene transcription
puberty associated changes in male
Growth-promoting properties: muscle mass, skeletal, behavioral

Question 6

Clinical Uses of Pharm Testosterone (4)

Answer 6

As androgen replacement therapy in hypogonadal boys/men
Osteoporosis
Muscle wasting associated with AIDS
Abuse for anabolic effects in sports

Question 7

Hormone (T) replacement therapy in aging men is controversial. Only in those with multiple abnormal readings who are also having symptoms

Answer 7

:)

Question 8

T is rapidly degraded by the liver in the first pass effect when given orally

Answer 8

:)

Question 9

Routes of T administration (7)

Answer 9

IM injection q 1-3wks
Transdermal gel q 24h, most expensive
Transdermal patch q day, severe rash associated
Subcutaneous pellet q 3-4mo
Buccal Tablet 2x daily
Nasal gel 3x daily
Oral

Question 10

Adverse effects of T supplementation in hypogonadism

Answer 10

Puberty signs - acne, gynecomastia, aggressive sexual behavior
Possible increase of hematocrit via erythropoeisis
Mild Na+ retention can exacerbate HTN

Question 11

Adverse effects of T supplements in athletic abuse

Answer 11

Decreased spermatogenesis and testicular atrophy
Increases susceptibility to platelet aggregation
Psychiatric symptoms - aggresivity
Gynecomatia if aromatization into estrogens occurs

Question 12

Anti-androgen targeting GnRH receptor

Answer 12

Competitive inhibition with GnRH antagonists
Inhibition with continuous GnRH agonists (Leuprolide)
Stimulation with pulsatile GnRH agonists

Question 13

Anti-androgen targeting CYP17

Answer 13

inhibits testosterone synthesis, ie: ketoconazole

Question 14

anti-androgen targeting 5-alpha-reductase

Answer 14

inhibits DHT synthesis.
Finasteride (proscar) - type 1
Dutasteride (Advodart) - type 1 and 2

Question 15

Anti-androgen targeting androgen receptor

Answer 15

EX: inhibition by flutamide or spironolactone

Question 16

Androgen Use: Prostate CA

Answer 16

GnRH agonists continuously plus androgen receptor antagonists to prevent flare

Question 17

Androgen Use: BPH

Answer 17

5-alpha-reductase inhibitor AFTER failure of Alpha-1 adrenergic antagonist

Question 18

Androgen Use: alopecia

Answer 18

5-alpha-reductase inhibitor in lower doses than in BPH

Question 19

Androgen Uses: precocious puberty in boys

Answer 19

GnRH agonists continuously

Question 20

Finasteride Side Effects

Answer 20

5-alpha-reductase inhibitor

Decreased libido, erectile dysfunction, weakness

Question 21

Leuprolide Side Effects

Answer 21

GnRH analong.

HA, nausea, injection site irritation, hypogonadism with prolonged tx

Question 22

Spironolactone Side Effects

Answer 22

Androgen receptor antagonist

Hyperkalemia, gynecomastia