thyroid

Question 1

associated with hyper metabolic and hyperadrenergic symptoms (tachycardia, palpitations, insomnia, anxiety, tremor, heat intolerance, weight loss)

Answer 1

hyperthyroidism

Question 2

treats hyperthyroidism by inhibiting thyroid peroxidase and 5’ deiodinase - decreasing conversion of T4 into T3

Answer 2

propylthiouracil (PTU)

Question 3

actions of thyroxine

Answer 3

growth: bone in children, brain in fetal life and 1st year of postnatal life (lack thyroid hormone in fetal life cretinism)

Question 4

ADR: severe hepatotoxicity, maculopapular rash, drug induced lupus, agranulocytosis

Answer 4

propylthiouracil

can be used in 1st tri

Question 5

ADR: drug induced lupus, 1st trimester teratogen (b/c of extensive protein binding), cholestatic dysfunction

Answer 5

methimazole

Question 6

used in 2nd and 3rd trimester of pregnancy tp avoid PTU liver toxicity in later trimesters

Answer 6

methimazole

Question 7

uses for PTU and methimazole

Answer 7

1) graves
2) radioactive iodine conjunction
3) preoperative preparation of thyroid gland
4) thyrotoxic crisis

Question 8

associated with dry brittle hair, lethargy, fatigue, weakness, decreased BMR, cold intolerance, myxedema, lack appetite, weight gain

Answer 8

Hypothyroidism

Question 9

untreated hypothyroidism can lead to

Answer 9

myxedema coma

Question 10

treats hypothyroidism and hashimotos

Answer 10

levothyroxine (synthetic T4)

Question 11

ADR: hyperthyroidism, tachycardia, heat intolerance, tremors

Answer 11

levothyroxine

Question 12

used to tx myxedema coma (emergency)

ADR: avoid in heart dz

Answer 12

liothyronine sodium

Question 13

thyroid hormone biologically available in tissue

Answer 13

T3

Question 14

growth: bones in children, brain in fetal life and 1st few years postnatal life (lack of thyroid hormone in fetal life - cretinism) and effects on cardio (increase HR, BF, CO, contraction))

Answer 14

actions of thyroxine

Question 15

thyroid hormone synthesis

Answer 15

1) uptake of iodide (trapping)
2) iodide organification : oxidation and iodination
3) coupling of MIT and DIT
4) secretion of thyroid hormones
5) conversion of T4 to T3 (peripheral conversion)

Question 16

combo of two DIT 
less potent
75% protein bound
.04% exists in free form
converted to T3 in the peripheral tissues, liver, and kidneys

Answer 16

T4

Question 17

combo of one MIT and one DIT
4 times more potent 
25% bound
.4% exists in free form
binds actively to nuclear receptor (active form)

Answer 17

T3

Question 18

protrusion of the eyeball
ulceration of cornea
stretches the optic nerve to damage vision

Answer 18

exophthalmos

Question 19

TSH decrease
Free T3 increase
Free T4 increase
RAI increase

Answer 19

Graves dz

Question 20

TSH decrease
Free T3 increase
Free T4 increase
RAI decrease

Answer 20

sub acute thyroiditis

Question 21

TSH decrease
Free T3 increase
Free T4 increase
RAI decrease/normal

Answer 21

exogenous T3 or T4

Question 22

TSH increase
Free T3 decrease
Free T4 decrease

Answer 22

primary hypothyroidism

Question 23

TSH normal
Free T3 normal
Free T4 normal
RAI normal

Answer 23

total T4 increase

pregnancy TBG increase

Question 24

trapped by thyroid gland

radiation destruction of thyroid parenchyma

Answer 24

MOA of RAI

Question 25

Uses: graves dz: px with heart dz (after making them euthyroid) and toxic nodular goiter

Answer 25

RAI

Question 26

antithyroid drugs should be discontinued 1 week before and resumed 3 days after 131I therapy (decrease efficacy) iodides should be avoided to prevent competition in uptake

Answer 26

Admin of RAI

Question 27

avoid in pregnancy and lactating mothers | can cause hypothyroidism

Answer 27

RAI

Question 28

increase delayed hypothyroidism increase stomach, kidney, breast cancer increase radiation

Answer 28

disadvantages of RAI

Question 29

no risk of surgery | decrease cost

Answer 29

advantages of RAI

Question 30

competitively inhibiting the NIS (inhibit uptake of iodine) | large doses can overcome competitive inhibition

Answer 30

ionic inhibitors

Question 31

ionic inhibitors

Answer 31

thiocyanate perchlorate fluoroborate = perchlorate

Question 32

used to tx iodide induced hyperthyroidism like amiodarone induced thyrotoxicosis

Answer 32

perchlorate

Question 33

10 times x thiocyanate | aplastic anemia

Answer 33

perchlorate

Question 34

inhibits the organification of iodine

Answer 34

thiocyanate

Question 35

iodides

Answer 35

lugols solution saturated solution of K iodide (KISS) K iodide

Question 36

MOA 1) imitation its own transport 2) inhibition of synthesis of iodotyrosine and iodothyronines 3) inhibition of the release of thyroid hormone 4) reduces vascularity and size

Answer 36

iodides

Question 37

uses 1) preoperative preparation of thyroid gland 2) thyrotoxic crisi - hyper metabolic state 3) radioactive iodine fallout

Answer 37

iodides

Question 38

competes with RAI not used long term due to escape vascularity is reduced gland becomes firmer

Answer 38

iodides

Question 39

ADR: marked sensitivity to iodide (allergy), IODISM: chronic intoxication with iodide (brassy taste in mouth), pulmonary edema, in pregnancy: iodide cross placenta and cause fetal goiter

Answer 39

iodides

Question 40

adjunct therapy

Answer 40

1) beta blockers without ISA - propanolol - use to control hyperthyroidism 2) dexamethasone 3) iopanic acid and sodium ipodate 4) cholestyramine 5) rituximab

Question 41

beta blockers with ISA CI in hyperthyroidism

Answer 41

``` carteolol labetalol penbutolol pindolol acebutolol ```

Question 42

thyrotoxicosis but exaggerated hyperthyroidism

Answer 42

thyroid storm

Question 43

tx for thyroid storm

Answer 43

1) antithyroid - propylthiouracil 2) B adrenergic blockers - tx HTN and increase HR 3) hydrocortisone - prevnts shock, inhibits peripheral conversion T4 -T3 4) oral iodides - iopanic acid and sodium update 5) tx underlying precipitating illness