Thyroid Pharmacology

Question 1

Levothyroxine

Answer 1

T4

Question 2

Liothyronine

Answer 2

T3

Question 3

Methimazole/Carbimazole

Answer 3

Thioamides

Question 4

Iodine 131

Answer 4

Iodine ablation

Question 5

Propylthiouracil

Answer 5

Thioamide

Question 6

Iodine 123

Answer 6

Thyroid imaging

Question 7

What decreases levothyroxine absorption?

Answer 7

Calcium, iron, AlOH, soy

Question 8

Levothyroxine side effects?

Answer 8

Palpitations, tremors, anxiety, weight loss, tachy, increased pooping
Arrhythmia/angina/MI
A fib in elderly

Question 9

What is the method of action of Thioamides?

Answer 9

Inhibit thyroid peroxidase

Question 10

What extra enzyme does propylthiouracil also inhibit?

Answer 10

Deiodinase 1 (peripheral T4 -> T3 conversion)

Question 11

What are thioamides the first line of defense against?

Answer 11

Graves disease

Question 12

What is KI used for?

Answer 12

Treats thyroid storm

Question 13

KI side effects?

Answer 13

Allergic reactions
Sore teeth and gums
Excess salivation

Question 14

What is a major side effect of PTU?

Answer 14

Hepatotoxicity

Question 15

Which sulfonylurea do you use first in thyroid treatment?

Answer 15

Methimazole

Question 16

When is PTU preferred to methimazole?

Answer 16

Pregnancy