Endocrine: Thyroid and Pituitary

Question 1

TRH also known as

Answer 1

hypothalamic thyroptropin

Question 2

TSH action is mediated by?

Answer 2

cAMP—- then leads to stimulation of iodine uptake by thyroid gland

Question 3

what is the stored formed of thyroid hormone

Answer 3

Thyroglobulin

Question 4

which is the active form of thyroid hormone we use in our ody

Answer 4

T3

Question 5

T3 or T4 participates in neg feedback to AP/Hypothal

Answer 5

T3

Question 6

what hormone blocks TSH

Answer 6

somatostatin

Question 7

is t3/t4 bound?

Answer 7

yes, to thyroxine-binding globulin in plasma

Question 8

what happens to T3/T4 once insdie target cell

Answer 8

T4 deiodinates to T3

Question 9

another name for GH

Answer 9

somatotropin

Question 10

highest levels of GH are released when

Answer 10

during sleep

Question 11

what inhbits GH release

Answer 11

somatostatin

Question 12

GH stimulates release of?

Answer 12

IGF-1 from liver

insulin-like growth factor 1

Question 13

ACTH hormone also called?

Answer 13

Corticotropin

Question 14

which hormone is used to differentiate Cushing syndrome from ectopic ACTH producing tumor

Answer 14

CRH

Question 15

highest times ACTH is realease?

lowest?

Answer 15

morning

*lowest=evening

Question 16

what stimulates ACTH realease? what inhibits it?

Answer 16

stim=stress

inhib=high levels of circulating cortisol via -feedback

Question 17

where does ACTH bind?

Answer 17

rec on adrenal CORTEX

Question 18

indications for corticotropin? (3)

Answer 18

1. diagnostic tool for differentiation b/w primary addison dz (prim adrenal insuff) and secondary
2. infantly spasms
3. MC

Question 19

indications for cosyntropin

Answer 19

PREFFERRED for diagnosis of adrenal insuff

Question 20

which is pref for diagnosis of adrenal insuff

Answer 20

cosyntropin

Question 21

AP hormone replacment therapy is adminitered how

Answer 21

IM
SC
IN
because they are very delicate and easily destructed by enzymes in digestive tract

Question 22

Somatotropin

Answer 22

GH

Question 23

Somatotropin
MOA
Indications
Application

Answer 23

MOA: many physiologic effects of GH exerted via at its targets…ohers are mediated by SOMATOMEDINS (IGF-1 and 2)

used in tx of GH deficiency
growth failure in kids
treatment of HIV with cachexia
GH replacement in adults with confirmed deficiency

Question 24

GH administered to adults does what?

Answer 24

increases LEAN body mass, bone density, skin thickness and decreases adipose tissue

Question 25

somatostatin inhibits realease of? (5)

Answer 25

``` GH TSH insulin glucagon gastrin ```

Question 26

where is somatostatin found

Answer 26

``` all over -intestine 0stomach -pancreas -hypothalmamus ```

Question 27

name the synthetic analogs of somatostatin

Answer 27

Octreotide | Leuprolide

Question 28

Indications for Octreotide

Answer 28

1. acromegaly * somatostatin analog 2. bleeding esophageal varices (IV) 3. Diarhhea/flushing episodes assoc with carcinoid tumors

Question 29

indications for Leuprolide

Answer 29

acromegaly *somatostatin analog Diarhhea/flushing episodes assoc with carcinoid tumors

Question 30

somatotropin is released in response to

Answer 30

GHRH

Question 31

PP hormones

Answer 31

oxytocin | ADH--vasopressin

Question 32

True false.. oxytocin has antidiruetic and pressor activities

Answer 32

TRUE | but less potent than ADH

Question 33

Vasopressin - effects? - binds to? - indications

Answer 33

antidiruetic and vasopressor effects -travels to kidneys--binds to V2 receptors****--increases water permeability and reabsoprtion in the COLLECTING TUBULES indication: - DI - sepsis - controls bleeding due to esophageal varices

Question 34

drugs used in tx of bleeding esophageal varices

Answer 34

vasopresin or Octreotide (somatostatin analog)

Question 35

Desmopressin MOA indications

Answer 35

analog to vasopressin first line for DI and nocturneal enuresis longer acting than vasopresin PO or intranasal

Question 36

``` Levothyroxine MOA INds SE onset of action? ```

Answer 36

synthetic T4 Inds: replacement tx for non-functional hypothyroid (Hashimoto for ex) MOA: T4 converted to its active metab--L-triiodothyronine aka T3--- then T3 and T4 bind to thyroid receptor proteins in the cell nucleus---- exert metabolic effects thru control of DNA transcription and protein synthesis onset takes 3-5 DAYS SE - nervousness - palps - tachycardia - heat/cold interolerance - unexplained wt loss

Question 37

drugs used to tx thyrotoxicosis or hyperT

Answer 37

or graves dz THIOAMIDES: Propylthiouracil (PTU) or Methimazhole

Question 38

goal of therapy in graves?

Answer 38

to decrease synthesis and/or release of additional hormone - remove part of all of the thyroid gland (surgical) - inhib synthesis of the hormones (PTU/Methimazole) - blocking release of hormones from follicle (dose of iodide)

Question 39

PTU and Methimazole | MOA

Answer 39

MOA: PTU: blocks peripheral conversion of T4--T3 (NOT M) BOTH: block oxidative process req for iodination rxn to convert T4--3 *NO EFF ON THYROGLOBULIN already stored in gland

Question 40

why is Methimazole prefered over PTU

Answer 40

longer half life---letting it be dosed once daily and less SE

Question 41

why might clinical effects of Thioamides be delayed?

Answer 41

beacuse the drugs have no effects on the already stored thyroglobulin in the TG--- so these stores need to be depleted before the treatment starts really showing

Question 42

hyperthyroidism and pregnancy tx?

Answer 42

PTU | *bc the M one is teratogenic

Question 43

SE for PTU

Answer 43

BBW: for liver toxicity Others: - bleeding - alopecia - exfoliative dermatits - SJS TEN - Urticaria - ANCA+ vasculitis - Interstitial pneumonitis

Question 44

Methimazole SE

Answer 44

``` edema drug fever drowsiness alopecia arthralgias nephritis Vertigo ```

Question 45

thryoid storm - causes? - S/S and onset

Answer 45

``` first presentations of graves or already diagnoses and: -trauma -MI -Exposure to iodine (EX: arthrogram) ``` Life threatening----10-25% of ppl develop HF and die super fast onset s/s= severe hyperthryoid symptoms

Question 46

TX for thyroid storm

Answer 46

BLOCK synthesis: PTU high dose (PO, NG or OG tube) BLOCK release: iodine SSKI potassium iodide drops q6 hours Block periphereal T4--T3 conversion: PTU Block the HR: BBs----> propranolol 1-2mg IV q15 minutes Bp: hydrocortisone Supplementary: hydrocortisone 100mg IV q6 hrs and IV fluids MUSTTTT

Question 47

why do we give hydrocortisone for thyroid storm tx?

Answer 47

help augment BP

Question 48

why do we give iodine in tx of hyperT

Answer 48

Iodine in PHARMACEUTICAL DOSES is administered to block the release of preformed thyroid hormone.

Question 49

drugs that can effect thyroid

Answer 49

AMIO--hypo or hyper lithium---- hyPO alpha interferon--HYPO