Thyroid pharmacology - French

Question 1

Drugs for hypothyroidism

Answer 1

*Levothyroxine (T4)
Liothyronine (T3)

[Liotrix] - mix of T3/T4, not commonly used
[Thyroid USP] - porcine. more potent. not recommended.

*First line for thyroid replacement

Question 2

Drugs for hyperthyroidism

Answer 2

**Methimazole (thionamides), Propylthiouracil

[SSKI (potassium iodide), Lugol’s solution (KI, I)] old school, only used as adjuvant therapy. Use in thyroid storm.
Radioactive iodine 131^I

** First line. 1x daily dosing, lower dose, little hepatotoxicity

Question 3

Levothyroxine

Answer 3

Hypothyroidism. T4 analog. First line for thryoid replacement.

Question 4

Liothyronine

Answer 4

Hypothyroidism. T3 analog. can be used for shorter term thyroid boost. Not as good for long-term dosing due to high cost and shorter half-life.

Question 5

Liotrix

Answer 5

Hypothyroidism

4:1 mixture of T4 and T3.

Question 6

Thyroid USP

Answer 6

Hypothyroidism.

Dessicated PORCINE thyroid extract containing thyroxine and liothyronine. Basically this drug sucks and no one uses it because levothyroxine.

Question 7

Propylthiouracil

Answer 7

Hyperthyroidism (thionamide)

**Blocks addition of Iodine to tyrosine. Also blocks conversion of T4–>T3

Question 8

Methimazole

Answer 8

Hyperthyroidism (thionamide)

**Blocks addition of Iodine to tyrosine

Question 9

SSKI, Lugols

Answer 9

Hyperthyroidism (Potassium iodide)

Question 10

Radioactive iodine 131^I

Answer 10

Hyperthyroidism. Uptake by thyroid, β-radiation causes a slow inflammatory process that destroys parenchyma of gland over weeks to months

Question 11

Name a TSH analog and what its indication might be?

Answer 11

Thyrotropin. Indicated for thyroid carcinoma. Increases uptake of 131I. Dont get confused if you see this on boards. Thyroid hormone analogs start with “L”.

Question 12

Which drug used to treat hyperthyroidism is used during pregnancy?

Answer 12

propylthiouracil

Question 13

What drug cocktail would you give a patient in thyroid storm?

Answer 13

1. PTU blocks T4–> T3 conversion
2. sodium iodide (IV), potassium iodide (oral)–> decrease hormone secretion
3. hydrocortisone to protect against shock and dampen immune response.
4. Propanolol - manage cardiovascular effects, blocks t3–>T4 conversion

Question 14

Which drugs prevent or slow the conversion of T4 to T3?

Answer 14

PTU (propylthioruacil)
Propanolol
Hydrocortisone