Thyroid High Yield Points Review

Question 1

What is thyroid storm?

Answer 1

Life threatening medical emergency associated with extreme effects of hyperthyroidism
–caused by illness, surgery, and other stresses in patients suffering from thyrotoxicosis
Beta blockers to manage CVS problems
PTU, IV sodium iodine and Glucocorticoids to inhibit peripheral conversion of T4 to T3

Question 2

These next few cards will mention other drugs that can be used for an Antithyroid drug. The first are Iodinated Radiocontrast Media, what are these drugs?

Answer 2

Diatrizoate (oral) or Iohexol (IV)

• suppress the conversion of T4 to T3 in the peripheral tissues, kidney and liver.
• -useful in rapidly reducing the T3 concentration in thyrotoxicosis.

Question 3

Next drugs are Perchlorate, Thiocyanate and Pertechnetate. what are some features?

Answer 3

Inhibit iodide concentration in the gland by blocking the transportation
–potential for aplastic anemia

Question 4

These next drugs may provoke autoimmune or destructive inflammatory thyroiditis, inducing hypothyroidism.

Answer 4

1. Amiodarone: has structural similarity to thyroxine
   - -iodine associated hyperthyroidism may occur and can be treated with thiamides
   - -Autoimmune mediated inflammatory version treated with steriods
   - -hypothyroidism: treated with levothyroxine
2. Interferon alpha and Interleukin 2
3. Lithium: inhibits release of hormones (hypothyroidism) and thyroid enlargement
4. Goitrogens: cabbage (Contains thiocyanate) , Cassava (contains carbs + thiocyanate)
5. Imatinib, Sunitinib (TKRI: tyrosine kinase receptors decrease)
6. Aminoglutethimide and Sulfonylureas

Question 5

Finally what are drugs that inhibit conversion of T4 to T3?

Answer 5

Corticosteriods
Propanolol
Amiodarone

Question 6

What is Graves Disease?

Answer 6

Antibodies produced in the disease activates thyroid gland TSH receptors

Question 7

What do Thioamides (methimazole and propylthiouracil) do?

Answer 7

Prevent MIT and DIT to form T4 and T3

–they cause hepatic damage, agranulocytosis, vasculitis and hypprothrombinemia

Question 8

What is a thyroid storm?

Answer 8

Beta blockers such as propranolol are used to control tachycardia and other CVS abnormalities

• -propanolol is also used to inhibit T3 from T4.
• -other drugs are high doses of iodide and PTU

Question 9

Iodides (Lugol’s Iodine) is used for what?

Answer 9

Inhibits synthesis, release of thyroid hormones and decrease the size and vascularity of the hyperplastic gland

Question 10

Amiodarone is used for what?

Answer 10

Antiarrhythmic agent

• -its iodine contents could produce complex effects on thyroid hormones
• -it also inhibit peripheral conversion of T4 to T3

Question 11

What is the only medical therapy that produces a permanent reduction in thyroid activity?

Answer 11

131-I

Question 12

What are therapeutic options in Graves Disease?

Answer 12

1. Surgery
2. Radioactive iodine to destroy the gland
3. Antithyroid drugs: PTU or Methimazole
4. Oral diatrizoate or oral/IV iohexol, iodine containing X-ray contrast material
5. Beta blockers: in thyrotoxic crisis
   131-I provides permanent care, useful in young people
   Iodide treatment is useful in reducing the hormone release, decreasing the size and vascularity prior to surgery.

Question 13

What agents are used in the case of Thyrotoxic Crisis?

Answer 13

Diatrizoate (Ipodate) is used to inhibit conversion from T4 to T3; faster onset of action.
Propranolol: used to decrease sympathetic effects
Thioamides, iodides (release block) IV and oral
Corticosteroids are also helpful
–for thyroid storm used PTU

Question 14

If hyperthyroidism occurs during pregnancy how can this be treated?

Answer 14

Surgical intervention to avoid the risk to the fetus and fetal thyroid

Question 15

Iodine has a negative feedback effect on the thyroid so this means?

Answer 15

Decrease in the rate of iodine uptake

Question 16

T4 is converted to T3 in peripheral tissues, liver and kidneys via what?

Answer 16

5-deiodinase