Endocrine Drugs - Thyroid

Question 1

liothyronine

Answer 1

T3
3-4x more active than levothyroxine

for hypothyroidism

Question 2

liotrix

Answer 2

4:1 combination of syn t4 & t3

for hypothyroidism

Question 3

propylthiouracil (PTU)

Answer 3

(-) thyroid peroxidase & condensation/coupling

addtl moa: (-) peripheral conversion of t4 to t3

safe for pregnant

thioamide
for hyperthyroidism

Question 4

methimazole (MMI)

Answer 4

(-) thyroid peroxidase & condensation/coupling

s/e: infertile hypothyroidism
can enter placenta

thioamide
for hyperthyroidism

Question 5

carbimazole

Answer 5

(-) thyroid peroxidase & condensation/coupling

s/e: infertile hypothyroidism
can enter placenta

thioamide
for hyperthyroidism

Question 6

teratogenic hyperthyroidism drug

Answer 6

methimazole
causes cutis aplasia

10x more potent than PTU, longer duration

Question 7

potassium perchlorate

Answer 7

(-) iodide uptake through competitive inhibition
s/e: aplastic anemia

anionic inhibitor/ inorganic anions
for hyperthyroidism

Question 8

thiocyanate

Answer 8

(-) iodide uptake through competitive inhibition
s/e: aplastic anemia

anionic inhibitor/ inorganic anions
for hyperthyroidism

Question 9

lugol’s solution

Answer 9

moa: wolf-chaikoff effect (inc negative feedback)
not for long term tx (may cause hydrotoxicosis aka jod-basdow phenomena)

CI: pregnancy

s/e: sialadenitis, conjuntivitis, rhinitis, yellow teeth

iodides
for hyperthyroidism

Question 10

potassium iodide saturated solution (KIss)

Answer 10

moa: wolf-chaikoff effect (inc negative feedback)
not for long term tx (may cause hydrotoxicosis aka jod-basdow phenomena)

CI: pregnancy

s/e: sialadenitis, conjuntivitis, rhinitis, yellow teeth

iodides
for hyperthyroidism

Question 11

iopnoic acid

Answer 11

(-) release and peripheral conversion of t4 to t3

radiocontrast dyes
for hyperthyroidism

Question 12

ipodate

Answer 12

(-) release and peripheral conversion of t4 to t3

radiocontrast dyes
for hyperthyroidism

Question 13

propanolol

Answer 13

inh peripheral conversion of t4 to t3
beta blocker
for hyperthyroidism

Question 14

prednisone

Answer 14

interferes w/ peripheral conversion of t4 to t3
glucocorticoids
for hyperthyroidism

Question 15

dexamethasone

Answer 15

interferes w/ peripheral conversion of t4 to t3
glucocorticoids
for hyperthyroidism

Question 16

radioactive iodine (RAI)

Answer 16

I131 (only isotop used for thyrotoxicosis)

emit high dose b radiation = dna damage
CI: pregnancy

for hyperthyroidism

Question 17

primary hyperthyroidism

Answer 17

tsh: low
t3: high
t4: high

Question 18

primary hypothyroidism

Answer 18

tsh: high
t3: low
t4: low

Question 19

secondary hyperthyroidism

Answer 19

tsh: high
t3: high
t4: high

Question 20

secondary hypothyroidism

Answer 20

tsh: low
t3: low
t4: low

Question 21

90% of the thyroid gland’s secretory product

Answer 21

t4
half life: 6 days

Question 22

stronger, more active

Answer 22

t3
half life: 1 day

Question 23

most common cause of hypothyroidism in developed countries

Answer 23

hashimoto’s disease

Question 24

most common cause of hypothyroidism in PH

Answer 24

iodine deficiency