Drugs Hypothalamo-pituitary Flashcards
2 hormones that stim GH?
Ghrelin
GHRH
what inhibits GH?
somatostatin
what hormone activates most actual growth?
IGF-1
What is growth hormone insensitivity?
liver won’t make IGF-1
what is growth hormone 2ndary deficiency?
pituitary is stuffed
what is growth hormone tertiary deficiency?
brain is not sending signals
what is somatotropin?
Growth Hormone
GH orally?
Nope. sucks. Parenteral admin
GH and T4?
can cause reduced T4 levels
Ghrelin and GHRH together does what?
synergize to release more GH
Ghrelin potential therapy for?
GH deficiency
IGF-1 replacement useful for what condition?
GH-insensitivity (Laron dwarfism)
anti-GH antibodies
IGF-1 side effects?
hypoglycaemia
Too much GH leads to?
Acromegaly
2 ways to reduce GH release?
- somatostatin analogue
2. dopamine agonist
what is pegvisomant?
GH antagonist
what happens to somatostatin receptors upon activation? so what?
internalisation
useful for imaging
somatostatin good reducer?
short half-life
G120K-GH works how?
doesn’t have the glycine at 120 so interrupts site 2 binding
what PEGylate something?
make it bigger, reduce renal filtration
what does pegvisomant sacrifice to get?
sacrifice affinity to get increased exposure
Hashimoto’s is what?
autoantibody destroys thyroid
what does stable isotopes of iodine do?
protect against radioactive iodine via sheer competition
Carbimazole does?
inhibit thyroid peroxidase
propylthiouracil does what 2 things?
- inhibit thyroid peroxidase
2. prevent t4-t3 conversion
Thioamines likely to cause what side effect?
hepatotoxicity
HAlf life of T4?
7 days
Why titrate T4?
heart is sensitive to it, could cause problems
What is Liothyronine?
T3
when use Liothyronine?
severe hypothyroid and myxoedema coma
what is myxoedema?
long term hypothyroidism
Cortisol does what to T3 and T4?
inhibits conversion of T4 to T3
t3 inhibits what?
cortisol production
