reproductive pharmacology Flashcards
describe the schematic for MOA of reproductive drugs that effect estrogen responses. where do these drugs act? (drawing)
clomiphene acts on the hypothalamus (-).
We have GnRH antagonists (-) and agonists (+/-).
oral contraceptives and danazole block the anterior pituitary release of FSH and LH.
ketoconazole (anti-fungal that blocks conversion of lanosterol to ergosterol) and danazole block P450c17, which is important for testosterone and androstenedione production.
Anastrozole blockes aromatase activity.
SERMs (+/-) and fulvestrant (-) block estrogen reponse elements. `
describe the schematic for MOA of reproductive drugs that effect androgen expression (drawing).
GnRH antagonists (-) and agonists (+/-).
LH–> testes (no drugs).
Ketoconazole and spironolactone block testicular testosterone prudction.
finasteride blocks 5-alpha reductase production of dihydrotestosterone (DHT).
flutamide, cyproterone, and spironolactone all block androgen receptor complex.
leuprolide: MOA, use, toxicity
GnRH analog. if given in a pulsatile fashion, it will act as an agonist; if given continuously, it will act as an antagonist (down regulates GnRH receptor in the pituitary –> decr. FSH and LH). used for infertility (pulsatile), prostate cancer (continuous), precocious puberty (continuous), uterine fibroids (continuous).
toxicity: antiandrogen, nausea, vomiting.
estrogens: drug names, mechanism, use, toxicity
DES, ethinyl estradiol, mestranol.
agonists at estrogen receptors.
used for ovarian failure or hypogonadism, menstrual abnormalities, HRT in post-menopausal women, men with androgen-dependent prostate cancer.
toxicity: DES can cause vaginal clear cell carcinoma to babies exposed in utero. all estrogens cause incr. risk of endometrial cancer, incr. risk of thrombi, bleeding in post-menopausal women. don’t give to women with history of estrogen positive breast cancer.
clomiphene: MOA, use, toxicity
antagonist at estrogen receptors in the hypothalamus prevents negative feedback and increases LH and FSH release to stimulate ovulation. used to treat infertility due to anovulation (PCOS). may cause hot flashes, ovarian enlargement, multiple simultaneous pregnancies, visual disturbances.
raloxifene: MOA, use, toxicity
estrogen agonist on bone, antagonist on the uterus. used for osteoprosis becasue it decreases bone resorption. incr. risk of thromboembolic events.
anastrozole: MOA, use, toxicity
aromatase inhibitor used for post-menopausal women with breast cancer.
exemestane works the same way.
mifepristone: MOA, use, toxicity
competitive inhibitor of progestins at the progesterone receptor. used with misoprostol to terminate pregnancies.
may cause heavy bleeding, GI effects, abdominal pain.
how do oral contraceptives work?
chronic administration of estrogen inhibit LH/FSH and thus prevent the estrogen surge. without the estrogen surge, there is no LH surge, and no ovulation.
progestins also thicken the cervical mucus and inhibit endometrial proliferation.
terbutaline
beta 2 agonist that relaxes the uteurs and decreases contraction frequency in labor.
danazol: MOA, use, toxicity
synthetic androgen that acts as a partial agonist at androgen receptors. used for endometriosis and hereditary angioedema. may cause weight gain, edema, acne, hirsutism, masculinization, decr. HDL, hepatotoxicity.
flutamide
nosteroidal competitive inhibitor of androgens at the testosterone receptor. used in prostate carcinoma
ketoconzale
inhibits steroid synthesis (17,20 desmolase). used in treatment of PCOS to prevent hirsutism. can cause gynecomastia and amenorrhea.
spironolactone
inhibits steroid binding, 17alpha hydroxylase, and 17,20 desmolase. used treat hirsutism in PCOS
finasteride
5 alpha reductase inhibitor (decreases conversion of testosterone to DHT). used in BPH. also promotes hair growth.
