Androgen Drugs

Question 1

Why is testosterone injected and not oral administration

Answer 1

Testosterone exhibits a high first pass effect when given orally

Question 2

What form of testosterone is given most often clinically

Answer 2

17b esterification (Type A; enanthate or cypionate)

• absorption is greatly delayed
• Injected subcutaneously or intramuscularly weekly / monthly
• are metabolized to testosterone

Question 3

How do steroid hormones like testosterone work in cells

Answer 3

Free steroid enters cell

Actions require transcription

Steroid actions are slow(er)

Question 4

Effects of androgens

Answer 4

Secondary Sex characteristics

appearance of pubic, axillary, and beard hair

sebaceous glands increase activity

thicker more oily skin

increased muscle mass

larynx grows and vocal cords become thicker - lower pitched voice

skeletal growth is stimulated and epiphysial closure accelerated

Question 5

What effect do a androgens have in the blood

Answer 5

Androgens stimulate RBC development

•direct effect:

recruitment of stem cells for RBC production

large pharmacological doses are required

•indirect effect:

stimulate synthesis of erythropoietin

Question 6

What happens to androgen level with age

Answer 6

•Androgen production in males declines ~1%/yr after age 40.

“Male menopause”

Does this cause age-related decreases in muscle mass, strength and sexual functioning???

Question 7

Side effects of androgens

Answer 7

Virializing effects (adolescent males and females)

Inhibition of spermatogenesis

Feminizing side effect

Hepatic abnormalities

Changes in lipoprotein profiles

Increase in aggressive behavior

Question 8

When would anti-androgens be used

Answer 8

hyperplasia and carcinoma of the prostate

male pattern baldness

virializing syndromes in women (e.g. hirsutism)

acne (esp. puberty)

Question 9

Actions of anti-androgens

Answer 9

1. Desensitization of GnRH receptors
2. GnRH receptor antagonist
3. Dec. Testosterone synthesis
4. Dec dihydrotestosterone synthesis
5. Competition to AR

Question 10

Examples of Long-acting GnRH analogs and how they work

Answer 10

Leuprolide acetate, Goserelin

pulsatile GnRH signals increase LH/FSH production

continuous levels actually has inhibitory effects

testosterone levels can fall to 10% of normal

but there is an initial flare

Question 11

Drug that targets type II testosterone (ginital) and used to treat BPH

Answer 11

Finasteride

Question 12

Anti-androgen that targets type I and type II testosterone

Answer 12

Dutasteride

Question 13

Anti-androgen used to treat metastatic prostate cancer

Answer 13

Abiraterone

Question 14

Examples of Androgen receptor antagonists

Answer 14

Cyproterone Acetate

Flutamide

Bicalutamide, nilutamide, and enzalutamide