10. Thyroid Pharm

Question 1

Levothyroxine

Answer 1

T4, preferred drug

Question 2

Liothyronine

Answer 2

T3, shorter half life, better absorption

Initial Tx for myxedema

Question 3

Liotrix

Answer 3

T3, T4 combination

Question 4

Anti thyroid agents (6)

Answer 4

PTU/MTU
Methimazole
Potassium perchlorate
Potassium iodide
Lithium
Iodine 131

Question 5

Which drug has an ADR of fetal aplastic anemia?

Answer 5

Potassium perchlorate

Question 6

MOA of potassium perchlorate

Answer 6

Inhibits anion pump (inhibits iodine trapping)

Question 7

MOA of potassium iodine, and what is it used for therapeutically

Answer 7

Inhibits hormone release, blocks iodine formation, blocks accumulation of radioiodine
TX for nuclear power plant accidents

Question 8

Lithium

Answer 8

Cause of hypothyroidism

Prevents iodine release from thyroid

Question 9

Iodine 131

Answer 9

Microcurie used for dx

Millicurie used for thyroid destruction

Question 10

What other drug can you use with anti-thyroids for positive effects?

Answer 10

Beta blockers

Question 11

Which drugs are effected by TH replacements

Answer 11

Coumadin, corticosteroids, digoxin

Increased catabolism of these drugs –> need to give more

Question 12

How should you administer Th replacements to patients with atherosclerosis or myocardial disease

Answer 12

Increase doses slowly so that heart can gain capacity to handle increased metabolic demands

Question 13

Which receptor does T3 bind to? T4?

Answer 13

T3R

Question 14

What are the thyroid hormone replacements

Answer 14

Levothyroxine
Liothyronine
Liotrix