PHARM Chapter 26 - Hypothalamus and Pituitary Gland Flashcards
3 Drugs for Growth hormone and insulin like growth factor replacement
Somatorpin (GH)/Somatrem
Semorelin (GRRH)/Tesamorelin
Mecasermine
ME of Growth Hormone and Insulin LIke Growth Factor Replacement
stimulate release of or replace growth hormone or insulin like growth hormone
Use of Somatorpin (GH) and Somatrem
Growth failure in children w/ GH deficiency
Turners syndrom
Prader Willi syndrome
Chronic kidney disease
Idiopathic short stature
Replacement of endogenous GH in adults w/ GH deficiency
Use of Sermorelin (GHRH) and Tesamorelin
Diagnostic evaluation of decreased plasma growth hormone (sermorelin) HIV lipodystrophy (tesamorelin)
Use of Mecasermin
Laron dwarfism, DH deficiency w/ neutralizing antibodies
Contraindication for Growth Hormone and Insulin-like growth replacement
active malignancy
Recombinant IGF-1
mecasermin
Why does IGF-1 serve as better measurement
bound and stable in the circulation for longer peroids of time at steady concentrations
Endogenous biological inputs that promote GH release include
GHRH, sex steroids, dopamine, ghrelin
Ghrelin acts w/ ___ to prommote GH release
GHRH
What is the most common cause of GH deficiency
defective hypothalamic release of GHRH, pituitary insufficiency, failure of IGF-1 secretion in response to GH
Alternative exogenous agents used to stimulate GH release
glucagon, arginine, clonide, and insulin
What is the main treatment for growth hormone excess
somatostatin receptor ligands
2 agnts that decrease growth horone secretion or action
Octreotide and pegvisomant
ME of octreotide and pegvisomant
inhibit GH release (octreotide)
antagonize GH receptor (pegvisomant)
Uses of Octreotide
acromegaly
able to control GI bleeding and reduce secretory diarrhea
flushing and diarrhea from carcinoid tumors
carcinoid crisis
diarrhea from vasoactive intestinal peptide-secreting tumors
TSH producing adenomas
Uses of pegvisomant
acromegaly
Contraindication for pegvisomant
known malignancy, pt. should have yearly MRI
Works on lactotrophs to physiologically inhibit prolactin release
dopamine
2 dopamine analogues
bromocriptine
cabergoline
GH analogue modified at one site to bind to GH w/ higher affinity than native model, preventing receptor dimerization required for subsequent receptor activation
Pegvisomant
How are lactotrophs unlike other cells of anterior pituitary
under tonic inhibition by the hypothalamus, mediated by dopamine - therefore in disease states, while other hormones will be decreased, prolactin will increase
What stimulates lactotrophs to secrete increasing quantities of prolactin
estrogen - although prolactin negatively feedbacks to suppress estrogen
How does prolactin negatively feedback to suppress estrogen
antagonizes hypothalamic release of GnRH and by decreasing gonadotroph sensitivity to GNRH
Agents that decrease prolactin levels
bromocriptine
cabergoline
Uses of bromocriptine
amenorrhea and galactorrhea from hyperprolactinemia
acromegaly
Parkinson’s
Premenstrual syndrome
Uses of cabergoline
hyperprolactinemia
Benefit to using cabergoline over bromocriptine
produces less nausea due to weekly or bi-weekly dosing interval and less frequent GI adverse effects
Ergot alkaloid
Bromocriptine
How can GI side effects be reduced in bromocriptine
intravaginal administration
Agents that Test thyroid function or stimulate iodide uptake
Protirelin
Thyrotropin
Uses of protirelin
diagnosis of thyroid function
uses of thyrotropin
adjunctive treatment of malignant tumor of thyroid gland
Contraindications for thyrotropin
adrenal insufficiency
coronary thrombosis
SE of protirelin
amaurosis fugax (in pt. w/ pituitary tumors) seizures
SE of thyrotropin
anaphylactoid reaction w/ repeated administration
nausea, vomiting, asthenia, headache
Used to stimlate radioactive iodide uptake in treatment of thyroid cancer
Thyrotropin
What is the main test used in screening for primary thyroid disease
serum TSH
Agent that test adrenal function
cosyntropin (ACTH 1-24)
ME of cosyntropin
stimulates adrenal cortisol and androgen production
Uses of cosyntropin
diagnosis of adrenocortical function
POMC is split into
POMC, MSH, lipotropin, and B-endorphin
ACTH has a trophic effect on the
zona fasciculata and zona reticularis of the adrenal cortex
ME of Gonadorelin (GnRH analogue)
COntinuous form: inhibits LH and FSH release
Pulsatile: stimulates LH and FSH release
Uses of Gonadoreline
Diagnosis of hypogonadism, stimulates ovulation
Multiple applications of GOnadoreline
anaphylaxis
ME of goserelin histrelin leuprolide nafarelin
Continous: inhibit LH and FSH release
Pulsatile: stimulates LH and FSH release
Uses for Goserelin
Histrelin
Leuprolide
Nafarelin
breast cancer prostate cancer endometriosis precocious puberty acute intermittent porphyria
SE of leuprolide
pituitary apoplexy
ME of ganirelix and cetrorelix
GnRH receptor antagonist
Uses of ganirelix and cetrorelix
inhibition of premature LH surges in women undergoing controlled ovarian hyperstimulation
SE of ganirelix and cetrorelix
ectopic pregnancy, thrombotic disorder, spontaneous abortion (Ganirelix) and anaphylaxis (cetrolix)
ME of Follitropin (rFSH) and Urofollitropin (FSH)
Stimulate gonadal maturation and steroid production
Uses of rFSH and FSH
ovulation induction
male hypogonadotropic hyogonadism
ME of conivaptan and tolvaptan
Mixed V1/V2 receptor antagonists
Uses of conivaptan and tolvaptan
Euvolemic and hypervolemic hyponatremmia Heart failure (tolvaptan)
Conivaptan is a ___ substrate
P450-3A4 substrate, contraindicated w/ other P450-3A4 drugs (clarithromycin and indinavir)
Tolvaptan is ___ antagonist
Vasopressin V2 receptor
inhibitin is produced in ___ and effects ___ secretion
gonads, GSH
activiin
paracrine factor produced and acts locally in pituitary and gonads to stimulate FSH
V2 receptors
located in nephron, stimulate cell surface expression of water channels in order to increase water reabsorption
ADH maintains vascular tone by
increasing blood pressure and increasing water reabsorption
Disruption of ADH can lead to
SIADH or diabetes inspidus
Demeclocylcine and ltihium
tetracycline antibiotic can treat SIADH
Administration of ADH analogue ____ results in stimulation of V2 receptors in neurogenic diabetes inspidus
desmopressin
Patients w/ diabetes inspidus can be treated with diuretics such as
amiloride or hydrochlorothiazide - prevents excessive loss of free water - induce volume contracted state to promote enhanced absorption of wtaer
