Thyroid

Question 1

Thyroid hormones are made in the ____ cells of the thyroid

Answer 1

Follicular

Question 2

T_ is more potent than T_

Answer 2

T3 is more potent than T4

Question 3

T4 is converted to __

Answer 3

T3

Question 4

What hormone from the hypothalamus stimulates the anterior pituitary to release TSH?

Answer 4

TRH

Question 5

Causes of hypothyroidism

Answer 5

Autoimmune/Hashimotos
Iodine deficiency
Pituitary dysfunction

Question 6

Causes of hyperthyroidism

Answer 6

Autoimmune/Graves
TSH secreting qdenomq

Question 7

Drug version of T4

Answer 7

Levothyroxine

Question 8

Levothyroxine is ____ protein bound

Answer 8

Highly

Question 9

Levothyroxine is ___ potent than liothyronine

Answer 9

Less potent

Question 10

Levothyroxine can be given IV to treat what?

Answer 10

Myxedema coma

Question 11

Uses of Levothyroxine

Answer 11

Hypothyroidism
Myxedema coma
Thyroid cancer (suppress TSH)
Post thyroid removal

Question 12

Drug version of T3

Answer 12

Liothyronine

Question 13

Liothyronine has ___ onset and ____ duration of action

Answer 13

Rapid onset
Short duration of action

Question 14

Liothyronine is ___ protein-bound than Levothyroxine

Answer 14

Less (higher potentcy and rapid degeneration)

Question 15

Clinical uses of liothyronine

Answer 15

Not used for chronic therapy
Short term for radioiodine treatment
Surgery for thyroid cancer to suppress TSH (only until T4 takes effect)

Question 16

Side effect of thyroid replacement hormones

Answer 16

Hyperthyroid symptoms if overdosed

Question 17

Levothyroxine interacts with which drugs

Answer 17

Vitamin K-dependent clotting factors (warfarin)
Cqtecholamines

Question 18

Thioamide drugs

Answer 18

Methimazole
Propylthiouracil

Question 19

Thioamide MOA

Answer 19

Inhibit peroxidase enzyme
Does NOT inhibit release of preformed TH

Question 20

Clinical uses of thioamides

Answer 20

First line therapy for hyperthyroidism

Question 21

Side effects of thioamides

Answer 21

Agranulocytosis (life threatening)
Hypothyroidism

Question 22

Thioamide drug with higher potency and longer duration of action

Answer 22

Methimazole

Question 23

What is different about the MOA of propylthiouracil than methimazole?

Answer 23

Also converts T4 to T3 in addition to inhibiting peroxidase

Question 24

Hyperthyroidism treatment in pregnancy

Answer 24

Propylthiouracil in 1st trimester then switch to Methimazole

Question 25

Clinical uses of potassium iodide

Answer 25

Protection against thyroid damage from release of radioactive iodine from nuclear accidents Thyroid storm Prior to thyroidectomy to shrink gland

Question 26

Potassium iodide MOA

Answer 26

Acute inhibition of synthesis and release of THs Decreases size and vascularity of thyroid gland

Question 27

Clinical uses of radioactive iodine

Answer 27

Small doses for iodine uptake tracer studies (hyperthyroidism diagnosis, locate cancer) Large doses for destruction of thyroid