Pharmacology Flashcards
What are the clinical uses of estrogens?
Treat female hypogonadism
HRT
Prevents bone loss
Component of hormonal contraceptives
What are the clinical uses of progesterones?
Hormonal contraceptives (alone or with estrogen) Component of HRT to lower risk of endometrial cancer Assisted reproductive technology
What enzyme converts testosterone to DHT?
5α-reductase
What drugs inhibit 5α-reductase?
Finasteride
Dutasteride
Why do supraphysiologic levels of testosterone lead to testicular atrophy and decreased spermtogenesis?
Inhibit LH/FSH
Paradoxically, supraphysiologic doses of testosterone can result in gynecomastia. Why does this occur?
Aromatization of testosterone to estrogen
What are the sites of action of anti-androgens?
GnRH receptor
CYP17 (17α-hydroxylase)
5α-reductase
Androgen receptor
What drug is a GnRH analog?
Leuprolide
What is the anti-androgen MOA of ketoconazole?
Inhibits desmolase
Inhibits 17α-hydroxylase
(synthesis inhibitor)
What drugs are androgen receptor antagonists?
Bicalutamide
Spironolactone
What is the anti-androgen MOA of leuprolide?
GnRH analog
What is the anti-androgen MOA of dutasteride?
Inhibits 5α-reductase
What is the anti-androgen MOA of bicalutamide?
Androgen receptor antagonist
What is the anti-androgen MOA of finesteride?
Inhibits 5α-reductase
What class of drug(s) can be used to treat prostate cancer?
GnRH agonist
Androgen receptor antagonist
What is the anti-androgen MOA of spironolactone?
Androgen receptor antagonist
When would you use a 5α-reductase inhibitor to treat BPH?
Very large prostate
Intolerance of α-1 blockers
How can you treat precocious puberty in boys?
GnRH agonist
A woman with PCOS has hirsutism, what anti-androgen drug can be given to treat this condition?
Spironolactone
What drugs are SERMs?
Tamoxifen
Raloxifene
Clomiphene
Detail the antagonist actions of tamoxifen.
Breast cancer receptors
Hot flases
Detail the agonist actions of tamoxifen.
Endometrial receptors
Venous thrombosis
Prevents osteoperosis
Compare/contrast raloxifene with tamoxifen.
Raloxifen is like tamoxifen, however, it does not have agonist activity at the endometrium
What is clomiphene used for?
Induces ovulation- selectively blocks estrogen receptors at pituitary which increases FSH/LH output
What drug is a pure estrogen receptor antagonist?
Fulvestrant
Estrogen is not used alone to treat menopausal symptoms. What is given with estrogen and why?
Progesterone
Decreased risk of endometrial cancer
What drugs are aromatase inhibitors?
Anastrozole
Exemestane
What are aromatase inhibitors used to treat?
Breast cancer that is ER positive
What is the MOA of anastrozole?
Aromataste inhibitor
What drug is a competitive inhibitor of progestins at progesterone receptors used to terminate pregnancy?
Mifepristone
What drug is administered with mifepristone and what is its MOA?
Misoprostol- PGE1 analog
What is the MOA of exemestane?
Aromatase inhibitor
What is the MOA of estrogen-progesterone OCPs that inhibits ovulation?
Inhibit LH/FSH, thus prevent estrogen surge. Without the estrogen surge there is no LH surge and no ovulation.
How do OCPs inhibit pregnancy?
Inhibit ovulation
Progesterones-
Thicken cervical mucus
Inhibit endometrial proliferation
What is the MOA of mifepristone?
Inhibits progestins
A drug with β2-agonist activity will have what effect at the uterus?
Relaxation
What drugs are uterine β2-agonists given to decrease contraction frequency during labor?
Terbutaline
Ritodrine
