Estrogen and Progestin Inhibitors

Question 1

Clomiphene MOA

Clinical?

Adverse?

When is it given?

Answer 1

PARTIAL AGONIST of estrogen receptor - BLOCKS ESTROGEN NEGATIVE FEEDBACK (not completely, just decreases it)

fertility drug

multiple births, hot flashes, ovary enlargement, blurred vision

dosing during FOLLICULAR PHASE

Question 2

Tamoxifen MOA

Answer 2

bone - agonist
endometrium - partial agonist
Breast/HPG axis - antagonist

ER+ breast CA

hot flashes, endometrial CA, nausea, vomiting

Question 3

Raloxifene MOA

Clinical?

Adverse?

Answer 3

bone - agonist
breast/uterus/HPG axis - antagonist

CA
post-menopausal bone loss

hot flashes, nausea, vomiting

Question 4

Danazol MOA

Clinical?

Adverse?

Answer 4

INHIBITS GONADAL FUNCTION

endometriosis
breast fibrocystic disease

wt +, edema, oily skin, acne, hirsutism, hot flashes - related to metabolite

Question 5

Anastrozole and Letrozole MOA

Clinical?

Adverse?

Answer 5

aromatase inhibitor

breast CA

GI disturbances, hot flashes, lethargy

Question 6

Mifepristone MOA

Answer 6

PROGESTERONE RECEPTOR ANTAGONIST

abortifacient - less than 7 weeks gestation, 1st admin mifepristone, 48 hrs later misoprostol

Question 7

Ulipristal MOA

Answer 7

PARTIAL PROGESTERONE RECEPTOR AGONIST

emergency contraceptive - longer acting, can be used up to 5 days after intercourse

Question 8

Anti-progesterone mechanisms of action (4)

Answer 8

inhibit progesterone receptors

uterine contractions

shed uterus lining

opens cervix