Reproductive/Endocrine Flashcards
GnRH analog with agonist properties when used in pulsatile fashion; antagonist
properties when used in continuous fashion
(downregulates GnRH receptor in pituitary
that decreases FSH/LH).
Leuprolide
What drug causes transient increase in pituitary LH secretion; which leads to a rise in testosterone levesl; continuous use will suppress LH release and leads to a decrease in testosterone levels
Leuprolide
Antagonist at estrogen receptors in hypothalamus. Prevents normal feedback inhibition and
increases release of LH and FSH from pituitary, which stimulates ovulation
clomiphene
Antagonist at breast; agonist at bone, uterus; increased risk of thromboembolic events and endometrial
cancer.
tamoxifen
Antagonist at breast, uterus; agonist at bone; increased risk of thromboembolic events but no increased risk
of endometrial cancer (
raloxifene
Anastrozole, letrozole, exemestane are examples of:
aromatase inhibitors
Inhibit peripheral conversion of androgens to estrogen.
aromatase inhibitors
Used for relief or prevention of menopausal symptoms (eg, hot flashes, vaginal atrophy),
osteoporosis ( increased estrogen, decreased osteoclast activity).
Unopposed estrogen replacement therapy ; increased risk of endometrial cancer, so progesterone is added.
Possible increased cardiovascular risk.
hormone replacement therapy
Agonists at androgen receptors
testosterone, methyltestosterone
5α-reductase inhibitor (decreases conversion of
testosterone to DHT).
Used for BPH and malepattern
baldness.
Finasteride
Inhibits steroid binding, 17α-hydroxylase, and
17,20-desmolase.
Spironolactone
Inhibits steroid synthesis (inhibits
17,20-desmolase).
Ketoconazole
Nonsteroidal competitive inhibitor at androgen
receptors. Used for prostate carcinoma.
Flutamide
α1-antagonist used to treat BPH by inhibiting smooth muscle contraction. Selective for α1A,D receptors (found on prostate) vs vascular α1B receptors.
tamsulosin
Direct arteriolar vasodilator.
minoxidil
used to treat androgenic alopecia
minoxidil
Sildenafil, vardenafil, tadalafil are examples of:
phosphodiesterase type 5 inhibitors
Inhibit PDE-5 which increases cGMP and causes prolonged
smooth muscle relaxation in response to NO which increases blood flow in corpus cavernosum of penis,
and decreases pulmonary vascular resistance.
phosphodiesterase type 5 inhibitors
Risk of life threatening hypotension in patients taking nitrates
phosphodiesterase type 5 inhibitors
Synthetic androgen that acts as partial agonist at androgen receptors.
danazol
MC SE of danazol
decreased HDL levels and hepatoxicity
β2-agonists that relax the uterus; used to decrease contraction frequency in women during labor.
terbutaline, and ritodrine
Produces local inflammatory reaction toxic to sperm and ova, preventing fertilization and implantation; hormone free.
copper IUD
Estrogen and progestins inhibit LH/FSH and thus prevent estrogen surge. No estrogen surge no
LH surge no ovulation.
Combined contraception
Competitive inhibitors of progestins at progesterone receptors.
Mifepristone, ulipristal
**Termination of pregnancy (mifepristone with misoprostol); emergency contraception (ulipristal)
Bind progesterone receptors, decreased growth and increased vascularization of endometrium, thicken cervical
mucus.
progestins (Levonorgestrel, medroxyprogesterone, etonogestrel, norethindrone, megestrol, and many others
when combined with estrogen)
MOA: work by suppressing pituitary LH secretion and subsequently decreasing ovarian androgen production.
Oral contraceptives
inhibition of phospholipase A2, and inhibition of
transcription factors such as NF-κB.
glucocorticoids
Sensitizes Ca2+-sensing receptor (CaSR) in parathyroid gland to circulating Ca2+ which decreases PTH.
cinacalcet
Synthetic analog of aldosterone with little glucocorticoid effects.
fludrocortisone
ADH antagonist (member of tetracycline family)
democycline
Propylthiouracil (PTU), methimazole are examples of
Thionamides
Inhibit oxidation of iodine to iodine by thyroid peroxidase
Thionamides
Inhibit iodination of tyrosyl resides (organification) on thyroglobulin to form MIT and DIT
Thionamides
Inhibiting coupling of MIT and DIT to form T3 and T4
Thionamides
Inhibit proteolytic release of T3 and T4 from thyroglobulin
High doses of iodide
inhibit conversion fo T4 to T3 via 5` deiodinase in peripheral tissues
Propranolol and Propylthiouracil (PTU)
Acromegaly, carcinoid syndrome, gastrinoma, glucagonoma, esophageal varices.
Somatostatin analog (octreotide)
What is a multifunctional enzyme responsible for catalyzing the oxidation of iodide, the iodination of thyroglobulin and the coupling reaction between 2. iodized tyrosine residues?
thyroid peroxidase
What removes the iodine groups from MIT and DIT for recycling?
iodotyrosine deiodinase
uptake of iodide from the blood is an energy dependent process carried out by?
the na-iodide symporter ; TSH stimulates this uptake and competitively inhibited by perchlorate and pertechnetate
What drug is 40% iodide by weight, thus can cause a number of alterations to thyroid function? IT can cause hypothyroidism due to decreased production of thyroid hormone. or hyperthyroidism by increasing thyroid hormone synthesis or destructive thyroiditis
Amiodarone
decrease androgen aromatization
aromatase inhibitors
decrease androgen synthesis
ketoconazole
decreased follicular cell stimulation
continuous GnRH stimulation by long acting GnRH analogs (ex. goserelin) suppresses LH and FSH release;d creating production of estrogens in the ovarian follicle.
decrease thyroid hormone synthesis by inhibiting thyroid peroxidase
PTU and methimazole
The most likely biochemical target of pioglitazone is:
intracellular nuclear receptor
Which selective estrogen receptor modulator inhibits the effects of estrogen on breast tissue and is effective for prevention and treatment of gynecomastia in patients on ADT?
Tamoxifen
The glucose lowering effects of TZDs requires __________________and protein synthesis, it takes several days to a few weeks after commencing TZd to observe significant results
alteration in gene transcription AKA transcription modulation
Glucocorticoids cause an increase in what organ’s protein synthesis ?
Liver protein synthesis ; by increasing hepatic glycogenesis and gluconeogenesis
An increase in estrogen activity (raises or lowers) circulating ____ levels?
raises circulating TBG levels; so there will be an increased total T4 pool.
impairs ligand receptor binding?
flutamide
Decreased leydig cell stimulation by LH
leuprolide, goserelin, nafarelin, histrelin
Decrease synthesis of testosterone in the leydig cells of the testis
ketoconazole
Decreased peripheral androgen aromatization occurs with
aromatase inhibitors
3 parts to Hyperthyroidism treatment
Antithyroid drugs, radioactive iodine, surgical thyroidectomy
PTU and methimazole are associated with what SE?
agranulocytosis (absolute neutrophil count less than 500/mL
Check wbc count with differential for what antithyroid drugs?
PTU and methimazole * in patient that present with fever
Administration of what may prevent thyroid absorption of radioactive iodine isotopes by competitive inhibition?
Potassium iodide
anion inhibitors (perchlorate and pertechnetate) work by?
blocking iodide absorption by the thyroid gland via competitive inhibition
Thionamides (methimazole and PTU) work by?
decrease the formation of thyroid hormones by inhibiting thyroid peroxidase
iodide salts work by?
inhibiting synthesis as well as release of thyroid hormones
What occurs as a result of increased testosterone secretion or increased conversion of testosterone to DHT?
Hirsutism
What drug has anti-androgenic properties and is used to treat hirsutism?
spironolactone
Also, used to rx hirsutism are?
flutamide and finasteride
What is a GnRH agonist that causes first a transient increase then a decrease in both testosterone and DHT levels?
Leuprolide
What causes a discordant decease in DHT level?
finasteride
Mifepristone is an example of a?
anti-progestin
