It will cause endometrial hyperplasia, increasing the risk of endometrial cancer. Take progesterone with it to reduce hyperplasia effects of estrogen. Estrogen can antagonize PTH.
What are the natural and synthetic estrogens?
Premarin = natural
Ethinyl estradiol = synthetic
Diethylstilbestrol (DES) = synthetic
Adverse effects of estrogens?
Gall stones and pulmonary emboli risks
Increase risk of endometrial and Breast cancer
DES during pregnancy increases adenocarcinoma in female offspring.
Estrogen receptor antagonists:
What are the drugs and what is the mechanism of action?
Clomiphene "fertility pill"
fulvestrant (not high yield)
These drugs (clomiphene) inhibit negative feedback of estrogen by blocking estrogen on the hypothalamus and pituitary. This increases FSH and LH secretion. This is the first choice for ovulation inducing. Use also in polycistic ovarian disease. Use also to treat metastatic breast cancer (as there are estrogen receptors in breast)
Adverse effect of estrogen receptor antagonists?
osteoporosis (back pain)
multiple pregnancy risk increases (twins)
What does SERM mean?
What drugs are considered SERM?
Selective Estrogen Receptor Modulator
the (-fens are SERMS)
tamoxifen (must know)
Mechanism of SERMs
Because they are modulators, they act differently on different tissues.
They are partial agonists on estrogen receptors.
Agonists on blood, bone (reduce bone resorption), lipid metabolism (reduce LDL, increase HDL, good thing)
Antagonists on breast (first choice for breast is tamoxifen)
Partial agonist on endometrium (tamoxifen)
raloxifen antagonizes the endometrium (difference!!)
raloxifen is also a prophylaxic in breast cancer for women with increased risks.
Prevents and treats osteoporosis.
Anastrozole is a ______ and it (decrease/increases?) estrogen synthesis.
Anastrozole is used in ______ if patients cannot take tamoxifen.
Anastrozole is a Selective Inhibitor of Aromatase and it DECREASES estrogen synthesis.
Anastrozole is used in postmenopausal breast cancer if patients cannot take tamoxifen.
Name the progestins (hint they all are steroids or steroid sounding)
What are progestins used for?
-Hormone replacement therapy (used with estrogens to prevent endometrial hyperplasia (risk of endometrial cancer))
-Contraception (decreases endometrial cancer)
-Increases appetite in HIV/AIDS
Which two progestins have androgenic actions, and what are the adverse effects from it?
These are first and second gen progestins.
Increased androgen activity leads to hirsutism (hairy ass women) and acne.
Which two progestins are third and fouth gen?
What differences do they have with 1st and 2nd gen?
They increase lipid and glucose levels favorably for the fetus, they are pro pregnancy.
They have no androgen action.
This is why we administer progesterone for after implantation to support the fetus.
What is it and what's the significance?
Mifepristone is an antiprogestin (progesterone antagonist)
It is an emergency contraception and can terminate early pregnancy (up to 49 days, along with misoprostol (misoprostol induces vasoconstriction, thereby reducing bleeding)
Vaginal bleeding is adverse effect of mifepristone.
Explain the 2 mechanisms of action of contraceptives.
- Selective inhibition of gonadotropin release from the pituitary, especially thru midcycle LH surge (thus preventing ovulation)
- Making cervical mucus thicker and impairing sperm movement
Estrogen and Progestin combination vs Progestin only
Benefits of combination?
Adverse effects of combination?
-Decrease risk of ovarian cancer
-Decrease risk of Endometriosis and PID
-Decrease ectopic pregnancy
-Increased venous thrombosis and MI
-Increase chance of breast cancer
What are they and what are significance?
(-rones and strels)
norethindrone - oral daily
medroxyprogesterone - Depot injection
-may cause significant bone loss and thromboembolism
Levonorgestrel (L-norgestrel) - IUD (good for 5 years)
Etonogestrel - subdermal implant (good for 3 years)
Morning after pill
Oral L-norgestrel is plan B. It is most effective the first 24 hours.
Large dose of contraceptives for the first 24 hours.
Copper bearing IUD - supposedly mots effective, but it is invasive. Up to 5 days
Ulipristal acetate - within 5 days, not as effective (60%). It is a SPRM (progesterone replaces estrogen)
Process of testosterone maturation:
Testosterone turns into:
dihydrotestosterone via 5alpha reductase
- for external genitalia and hair follicles
estradiol via CYP19 (aromatase)
- for bones and libido
- for internal genitalia, skeletal muscle, erythropoiesis, and bone development
Methyltestosterone is an active orally, but can result in hepatotoxicity.
Danazol is a synthetic androgen which has anti-estrogenic activity (treats endometriosis (GnRH agonists are better). Primarily used in prevention of hereditary angioedema by increasing C-1 esterase inhibitor. Irreversibly deepens voice
Androgen receptor antagonist.
Use bicalutamide because flutamide causes hepatotoxicity.
What are the androgen receptor antagonists?
the (-tamides) bicalutamide and flutamide
finasteride - inhibits 5aReductase 2 enzyme, producing a reduction of dihydrotestosterone in prostate and skin. Useful for benign hypertrophy of prostate and male pattern baldness.
- may cause impotence and gynecomastia
Are GnRH agonists are anti-androgens that initially increase FSH and LH secretions "flare effect"
After about 2 weeks, a hypogonadal effect is achieved thru receptor down regulation. Use these drugs to treat prostate and breast cancer along with androgen receptor antagonists for the initial 2 weeks to counteract the flare effects.