Exam 3 likely questions for exam

Question 1

what is the drug of choice for thyroid hormone replacement?

Answer 1

levothyroxine/synthroid

Question 2

besides hypothyroidism what else is levothyroxine indicated for?

Answer 2

For TSH suppression in select nodules and thyroid cancers

Question 3

what does long term elevation of T4 (from high dose replacement or hyperthyroidism) increase the risk of?

Answer 3

may accelerate cardiac disease and osteoporosis

Question 4

What is important about treating Addison’s disease patients with hypothyroidism?

Answer 4

Thyroid hormone replacement must be done with cortisol, otherwise it is FATAL!

Question 5

What are the equivalent doses of thyroid hormone? (synthroid, armour, and cytomel)

Answer 5

100 mcg of T4 (Synthroid) ~ =
60 mg Thyroid USP (Armour) ~ =
25 mcg of T3 (Cytomel)

Question 6

the most common cause of hyperthyroidism is called?

Answer 6

Grave’s Disease (autoimmune)– antibodies stimulate TSH receptors

Question 7

hyperthyroidism due to graves disease is usually accompanied by what?

Answer 7

goiter and exophthalmos

also: pretibial myxedema

Question 8

what is the definitive tx for hyperthyroidism?

Answer 8

surgical removal or radioactive ablation of thyroid gland

Question 9

How are the MOA of methimazole and PTU similar? different?

Answer 9

they both inhibit the transformation of inorganic iodine to organic iodine blocking the production of thyroxine and inhibiting the formation of T3 and T4.

**PTU blocks the peripheral conversion of T4 to T3 while methimazole has minimal effects.

Question 10

what is the most feared side effect of methimazole or PTU?

Answer 10

Agranulocytosis

Question 11

what category is PTU?

Answer 11

Category D, considered safer than methimazole (and used in pregnancy only when benefit out weighs risk)

Question 12

Does propanolol affect the thyroid gland?

Answer 12

No, it mitigates sxs such as anxiety, tremors, palpitations, etc.

Question 13

MOA of iodine/SSKI?

Answer 13

large doses of iodine inhibit the release of thyroxine from thyroid gland

Question 14

how long is iodine/SSKI effective for?

Answer 14

2-3 weeks as the thyroid gland adapts and resumes secretion of thyroxine.

Question 15

what category drug is radioactive iodine (131 I)

Answer 15

Category X, given during pregnancy can irreversibly damage the fetal thyroid tissue. When given to a nursing mother, radioactive iodine can reach a baby through the breast milk

Question 16

How are men effected by radioactive iodine?

Answer 16

Men who receive RAI treatment for thyroid cancer may have decreased sperm counts and temporary infertility for periods of roughly two year

Question 17

what is the most severe manifestation of hyperthyroidism?

Answer 17

Thyroid storm

Question 18

what are some signs of thyroid storm?

Answer 18

high fever, irritability, delirium, vomiting, diarrhea, dehydration, hypotension and vascular collapse.
(Coma and death may occur…too late for signs then!)