Estrogens, Progestins, and Androgens Flashcards
Ovulation inducers (anti-estrogens) indication:
- Women with anovulatory cycles (unable to release egg)
- Women with PCOS
Name 2 drugs that are ovulation inducers:
1) Clomiphene citrate (SERM)
2) Letrozole (aromatase inhibitor) - off label use
Clomiphene citrate MOA:
1) Competitively inhibits estrogen receptors in hypothalamus
2) Negative estrogen feedback inhibited
3) Increased GnRH secretion, which results in FSH and LH release
4) Ovarian follicles grow at next ovulation (agonist in ovaries, but antagonist in hypothalamus)
Letrozole MOA:
1) Blocks conversion of testosterone and androstenedione to E2 and E1
2) Decrease negative estrogenic feedback at pituitary
3) Increased FSH release
Name a gonadotropin release hormone agonist:
Leuprolide acetate (lupron depot)
Leuprolide acetate indication:
1) Endometriosis
2) Uterine fibroids
3) Advanced prostate cancer
Leuprolide acetate MOA:
1) Agonizes pituitary GnRH receptors, interrupting its pulsatile stimulation
2) FSH and LH release inhibited
3) Ovarian estrogen and testicular testosterone production reduced (via receptor desensitization)
Leuprolide acetate AE:1
1) Menopausal sx (eg: hot flashes) - management: ltx with low dose estrogen
Vaginal estrogen therapies indication:
Local treatment of urogenital atrophy due to low estrogen levels - quickly restores urogenital health within 3 months
If woman is still experiencing vaginal sx after vaginal estrogen tx, what other therapy can be initiated?
Low dose systemic hormone therapy can be used at the same time
Are progestogens necessary with low dose vaginal txs?
No. (Only needed if systemic hormone therapy is also being used)
Estrogen acts as agonist in which tissues?
Breast, endometrium, bone (strong agonist)
Tamoxifen (breast cancer tx) acts as an agonist in which tissues?
Endometrium, bone (weak agonist)
Tamoxifen acts an antagonist in which tissue?
Breast
Raloxifene (used in osteoporosis tx) acts as an agonist in which tissue?
Bone (fair agonist)
Raloxifine acts as an antagonist in which tissues?
Breast, endometrium
Name a selective progestin receptor modulator (sprm):
Ulipristal acetate
Ulipristal acetate indication:
Moderate to severe sx of uterine fibroids in women eligible for surgery
Ulipristal acetate MOA:
1) Prevents progesterone from binding to the progesterone receptor (directly affects endometrium and fibroids)
2) Inhibits cell division and induces apoptosis, thereby decreasing size of uterine fibroids –> decreased bleeding and pain
What benefit does ulipristal acetate have over leuprolide acetate?
Less vasomotor SEs
What is the role of LH in male reproductive physiology?
LH interacts with receptors in testes Leydig cells to enhance testosterone synthesis
What is the role of FSH in male reproductive physiology?
1) Act on receptors in testes stroll cells to regulate spermatogenesis
2) Enhances synthesis of aromatase enzyme (converts testosterone to E2) and androgen binding protein