French Hypothal + Pit Pharm Flashcards
GH
- Drug Name
- What does it do?
- How is it given?
- Somatropin (recombinant GH)
- Stimulates IGF-1 + 2 - promotes linear and skeletal m. growth
- Given qd via SC injxn (better) or 3x a week IM
GHRH
- Drug name
- Action
- Tesamorelin → stim GH release
- GHRH analog for HIV pts with lipodystrophy - reduces excess abdominal fat
Synthetic GH is not the way to go for GH deficiency, other GHRH was pulled
*Pegvisomant is a GH R antagonist
Somatostatin
aka
- Action
- half life
aka SST, GH inhibiting H, Somatotropin Release Inhibiting Factor
Inhibits GH release via GPCR coupled to Gi
only 3-4 min following exogenous admin
Somatostatin analogs (2)
- How is it given?
- When are they given?
- Side effects
Octreotide - SC or IM
Lanreotide - SC
- Given to treat Acromegaly and gigantism:
but surgical resection is preferred. - Given to control bleeding from esophageal varices and GI hemorrhage:
constrict splanchnic arterioles
Side effects:
transient deterioration in glucose tolerance (hyperglycemia)
Preferred agent for adjuvant management of acromegaly with advantage of oral administration
cabergoline (DA agonist)
Pegvisomant
GH receptor antagonist
- binds to GH receptors, blocking GH access,
but
signaling transduction still activated
*Tesamorelin → stim GH release
How is prolactin regulated at the hypothalamus?
Main stimulus?
What does prolactin do?
under inhibitory control by hypothalamic DA at D2 rcptrs
suckling: 10-100 fold increase in 30 min
Fxn:
- stimulates milk production
- stim. proliferation and differentiation of mammary tissue during pregnancy
- Inhibits FSH/LH release + ovary response
- (lack of ovulation during breastfeeding)
Tx for prolactinomas
DA agonist
- decrease secretion and tumor size
- Bromocriptine, Cabergoline (preferred)
*remember cabergoline was also recommended as Preferred agent for adjuvant management of acromegaly with advantage of oral administration. It is a DA agonist.
Where is vasopressin made?
How does it work?
Main stimulus for release?
What can inhibit its release?
Supraoptic nuclei of hypothalamus
Mediated by V2 receptors (Gs) for renal action:
- increase rate of insertion of aquaporins into luminal membrane
- Antidiuretic effect
Action at V1 receptors (Gq):
- vasoconstriction at vascular smooth muscle
Stimulus 4 release:
- rising blood osmolality
- decrease in circulating blood volume
Release Inhibited by:
Alcohol
tx of choice for Central Diabetes Insipidus
(CDI is due to inadequate ADH secretion)
give:
- Desmopressin
- Chlorpropamide
Difference between Central Diabetes Insipidus and Nephrogenic diabetes insipidus
Central Diabetes Insipidus
- inadequate ADH secretion
Nephrogenic diabetes insipidus
- inadequate ADH actions
Causes of Nephrogenic diabetes insipidus
- congenital
- receptor + aquaporin mutation - Drug induced
- Lithium (reduces V2 rcptr mediated stim. of adenylyl cyclase)
- Demeclocycline (tetracycline antibiotic): inhibit ADH effect on distal tubule
Tx for Nephrogenic diabetes insipidus
- Low salt, low protein diet
- Thiazide diuretics: hydrochlorothiazide
- antidiuretic effect parallels ability to cause natriuresis
(cant pee effects same as causing you to pee out lots of salt) - NSAIDS: Indomethacin
SIADH tx (3) - use V2 R agonist or antag?
(incomplete suppression of ADH secretion under hyperosmolar conditions)
Tx: of hyponatremia
- restriction of water intake
- Demeclocycline
- V2 receptor antagonist
(remember that - Demeclocycline (tetracycline antibiotic) can cause Nephrogenic DI): inhibit ADH effect on distal tubule
Drugs inducing SIADH
- SSRIs
- Haloperidol
- TCADS
