Thyroid Pharmacology

Question 1

Myxedema coma

Answer 1

End-state untreated HYPOthyroidism
Characteristics:
1. HYPO-Na
2. HYPO-sugar
3. HYPO-thermia
4. Shock --> DEAD

Question 2

Tx for Myxedema coma

Answer 2

1. Large, IV T4 loading dose
2. Daily dose T3/T4
3. Hydrocortisone prevent adrenal crisis/insuficiency

Question 3

Drug inhibit iodination

Answer 3

1. PTU

2. methimazole

Question 4

Subacute Thyroiditis

Answer 4

1. Painful
2. High T4, low TSH, low RIU
3. High ESR

Question 5

Unique presentation of Graves disease

Answer 5

1. Pretibial Myxedema
2. Exophthalmos
3. Lid Retraction
4. Diplopia

Question 6

Molar pregnancy

Answer 6

placenta tumor –> secrete high hCG –> stimulate TSH receptor

Question 7

Molar pregnancy presentation

Answer 7

1. Grave disease w/o exophthalmos
2. high hCG
3. high RAI uptake neck

Question 8

Struma ovarii

Answer 8

hyperfunctioning thyroid tissue in ovaries –> small thyroid gland

Question 9

mutation associated with Bamforth Lazarus syndrome

Answer 9

homozygous mutation of TITF2

Question 10

PAX8 mutation

Answer 10

AD inheritance: for thyroid cell diifferentiation

Associated with renal agenesis

Question 11

TITF1 mutation

Answer 11

Hox transcription factor regulating tG

Also in lung, forebrain, pituitary => respiratory distress and neurological symptoms

Question 12

NIS mutation

Answer 12

mutation Na/I symporter = rate-limiting step

AR inheritance

Question 13

SCL26A4 importance

Answer 13

codes pendrin, for iodine efflux at apical membrane

Question 14

THOX1 and THOX2

Answer 14

codes NADPH oxidase, important for iodination

Question 15

Why conduct newborn screen at 3-5 days for HYPOthyroidism?

Answer 15

Large surge of TSH within 30 min of birth –> 3-5 days to prevent confounding factor

Question 16

Newborn screening methods for HYPOthyroidism

Answer 16

1. Primary T4 (then check TSH level)

2. Primary TSH screen

Question 17

Disadvantage of TSH screen

Answer 17

miss central hypothyroidism

Question 18

Primary HYPOthyroid lab

Answer 18

Low T4
High TSH (>200)

Question 19

TBG Deficiency lab

Answer 19

T3 uptake and T4 in opposite direction

Eg: high T3 uptake and low T4 level

Question 20

Central HYPOthyroid lab

Answer 20

T3 uptake and T4 in the same direction

Eg: low T3 uptake and T4 level

Question 21

Which pathway signaling is important in thyroid cancer?

Answer 21

MAPK singlaing

Question 22

Papillary cancer pathway

Answer 22

1. RET/PtC : pathway always on = growth

2. BRAF mutation

Question 23

Follicular pathway

Answer 23

1. Ras mutation

2. Pax8-PPAR fusion protein = decrease tumor suppresion

Question 24

Tx for Thyroid Storm

Answer 24

1. Beta blocker: Propanolol blocks T4 –> T3

2. Hydrocortisone: prevent shock

Question 25

Estrogen effect on Thyroid hormone

Answer 25

Estrogen increase TBG –> low free T4 –> hypothyroidism

Question 26

Drugs decrease TBG

Answer 26

1. Salicylates
2. Anti-seizure
   => hyperthyroidism