Pharmacology of Androgens Flashcards Preview

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Flashcards in Pharmacology of Androgens Deck (34)
1

What are the 3 androgens?

1. Testosterone
2. Androstenedione
3. Dehydroepiandrosterone (DHEA)

2

What is the main difference between testosterone and estradiol?

- methyl group on testosterone's 4 ring structure

3

What produces androgens?

- testis= leydig cells
- adrenal glands
- ovary= theca cells

4

Can production of testosterone come from progesterone?

YES via cytochrome P450 to androstenedione and then to testosterone.

5

To what is testosterone metabolized in the prostate?

- 5-alpha dihydrotestosterone (DHT) via 5 alpha reductase.
*testosterone is unchanged in other tissues (muscle, kidney...)

6

What is the most potent androgen required for sex development?

- DHT

7

What regulates androgen production?

- LH from the anterior pituitary
*receptors for LH are found on Leydig cells in the testes.

8

Where else are androgens produced?

- adrenal cortex

9

What regulates sertoli cells in the testes?

- FSH from the anterior pituitary

10

What stimulates the adrenal glands to secrete cortisol and sex steroids?

- adrenocorticotropin

11

What is sex hormone binding globulin (SHBG)?

- serum glycoprotein derived from liver that binds testosterone in circulation

12

What INCREASES sex hormone binding globulin (SHBG)? (aka less free testosterone in the circulation)

- estrogens
- thyroxine

13

What DECREASES sex hormone binding globulin (SHBG)? (aka more free testosterone in circulation)?

- androgens
- GH
- insulin

14

What are the pharmacologic actions of androgens?

- sperm production
- erythropoiesis
- positive nitrogen balance
- growth/development of hair, bone, and muscle.

15

*** What is the major use for androgens?

- replacement therapy in men who have reduced testosterone production (primary testicular insufficiency).

16

What are the available IM injection testosterones?

- cypionate= 2-3 weeks
- enanthate= 2-3 weeks
- propionate= 1-3 days

17

Where is a testosterone transdermal patch applied?

- scrotal skin bc it's thinner than other epidermis.

18

What are the actions of anabolic steroids (synthetic derivatives of testosterone)?

- increase muscle mass
- increase physical performance
- increase linear growth (children)

19

**** What is OXANDROLONE (anavar; oxandrin)?

- anabolic steroid used for PRIMARY and SECONDARY testicular failure.
- increases expression of secondary sex characteristics

20

*** What is secondary testicular failure?

- insufficient stimulation of testes by pituitary gonadotropins (hypogonadotropic hypogonadism).

21

What is an ADR of using androgen therapy to increase height of short children?

- premature closure of epiphyseal plates and virilization.
*best to combine with GH

22

What are the therapeutic uses of androgens?

- treatment of aplastic anemia (erythropoiesis)
- inoperable breast cancer
- postpartum breast pain
- malnutrition

23

**** What is DANAZOL (danocrine)?

WEAK androgen used for the treatment of:
- endometriosis
- fibrocystic breast disease
- PMS

24

What was the result of using testosterone supplementation to treat men with multiple sclerosis (MS)?

- improvement in cognitive performance
- slowing of brain atrophy
- increase in lean body mass
- potential neuroprotective effects in men with relapsing-remitting MS

25

What are some dose related ADRs of androgens (due to feedback inhibition as dose increases)?

- priapism (sustained erection); not due to feedback inhibition.
- suppression of gonadotropin
- gynecomastia
- decreased size of testis
- decreased spermatogenesis
- weight gain
- Na+ retention (edema, HTN)
- decreased HDL (atherosclerosis)
- hepatotoxic (jaundice, carcinoma)
- BPH
- prostatic cancer

26

What are some ADRs of androgen use in females?

- virilization
- DO NOT use in pregnancy (category x)

27

What is "Roid Rage"?

- feeling of invincibility to physical challenges

28

What must AndroGel and Testim now do on product labels?

- include boxed warning of ADRs

29

What are some toxic effects of anabolic steroids used by weightlifters?

- acne conglobata= papules, pustules, abscesses, and deep ulcerations.

30

What are contraindications for androgens?

- breast carcinoma
- prostate carcinoma
- serious cardiac, hepatic, or renal disease
- pregnancy (female)

31

**** How can we suppress synthesis of androgens (primarily used to treat SYMPTOMS of men with prostate cancer)?

1.stimulate feedback inhibition= GnRH agonists (LEUPROLIDE; lupron), which decreases testosterone production over time.
2. GOSERELIN ACETATE implant= LHRH analogue (GnRH analogue)
3. NAFARELIN= GnRH analogue nasal spray.
4. DEGARELIX= LHRH ANTagonist, which decreases testosterone rapidly.
5. suppress synthesis of androgen= KETOCONAZOLE, which decreases cytochrome P450.
6. 5 alpha-reductase inhibitors (FINASTERIDE and DUTASTERIDE)= suppress synthesis of androgen.
7. CYP17 inhibitor (ABIRATERONE)= suppress androgen synthesis in other cells other than the prostate.
8. blockade of androgen receptor= FLUTAMIDE, ENZALUTAMIDE, and SPIRONOLACTONE

32

*** What is a problem with ketoconazole?

- can block production of cortisol, so you may need to add corticosteroid when using this to suppress androgen synthesis.

33

Does finasteride or dutasteride (5 alpha-reductase inhibitors) suppress synthesis of androgen more quickly?

- finasteride
*dutasteride has a longer half-life though.

34

Does spironolactone also inhibit cytochrome P450?

YES