Estrogen/ Progestin Pharmacology

Question 1

What are the major risks of HRT

Answer 1

increased risk of breast cancer (due to oral progestin) and increased risk of stroke and PE (due to estrogen– increases clotting factors)

Question 2

What are the different SERMs and their uses/ adverse effects?

Answer 2

SERMs: Selective Estrogen Receptor Modulators

Clomiphene, Tamoxifen, Raloxifene

Question 3

Tamoxifen

Answer 3

Uses: ER/PR+ breast cancer

MOA: Antagonist at breast; Agonist at endometrium, bone

Adverse effects: increased risk of thromboembolic events, endometrial cancer

Question 4

Clomiphene

Answer 4

Clomiphene used for infertility tx

MOA: estrogen antagonist at hypothalamus (prevents normal feedback inhibition and increase release of FSH and LH, which stimulates ovulation)

Adverse effects: hot flashes, ovarian enlargement

Question 5

Raloxifene

Answer 5

MOA: Antagonist at breast, uterus
Agonist at bone

Uses: osteoporosis

Adverse effects: hot flashes, Increased risk of thromboembolic events, but no increased risk of endometrial cancer

Question 6

Ideal characteristics of SERM

Answer 6

Antagonist at breast and uterus

Agonist at bone, CV, CNS

Remember which SERM does this- at least with bone? Raloxifene

Question 7

Top tier contraceptive effectiveness (progestin-only)

Answer 7

1. Levonorgestrel IUD: Progestin-only IUD with steroid reservoir; Depo-provera, implanon (rod that supplies progestin)

MOA: Binds progesterone receptors- to decrease growth of the endometrium and thickens cervical mucus

Question 8

Second tier

Answer 8

Combined contraceptives: estrogen/progestin pills, vaginal ring (estradial + etonogestrol), patch

MOA: estrogens and progestins inhibit LH/FSH- prevent estrogen surge
No estrogen surge –> No LH surge –> No ovulation
Also cause thickening of cervical mucus and decreased endometrial growth (progestins)

Contraindications: smokers >35, patients with increased risk of CVD, migraine (spec. with aura), and breast cancer- mainly if post-menopausal

Question 9

Things to keep in mind before prescribing contraceptives

Answer 9

Cigarette use
HTN
Hx of clotting disorder
Valvular heart disease
Diabetes
Headaches with focal neurological symptoms
Acute or chronic liver dz
Allergy/ hypersensitivity reactions

Question 10

Copper IUD

Answer 10

Produces a local inflammatory response that is toxic to sperm and ova- preventing fertilization and implantation; hormone free

Adverse effects: longer menses, dysmenorrhea, risk of PID with insertion