Thyroid disorders important stuff

Question 1

What 2 drugs can cause hypothyroidism AND hyperthyroidism?

(this is a test question)

Answer 1

Amiodarone ≈ 3%
Lithium ≈ 0.7%

Question 2

What is the drug of choice in preparation of a thyroidectomy?

Answer 2

Propranolol (post surgery as well)

Question 3

What are the 2 antithyroid meds?

Answer 3

Methimazole (MMI)
Propylthiouracil (PTU)

Question 4

How do you convert between the two antithyroid meds?

Answer 4

300 mg propylthiouracil is roughly equivalent to 10 to 15 mg methimazole

Question 5

Methimazole (MMI):
1) What is the initial dose?
2) What is the maintenance dose?

Answer 5

1) 10-20 mg/day
2) 5-10 mg/day

Question 6

Which has a faster onset, MMI or PTU?

Answer 6

MMI (12 – 18 hours)

Question 7

Which has a boxed warning for severe liver injury and acute liver failure, MMI or PTU?

Answer 7

PTU

Question 8

PTU:
1) What is the initial dose?
2) What is the maintenance dose?

(important)

Answer 8

1) 150-450 mg/day
2) 100-150 mg/day

Question 9

(definitely important)

What are 2 reasons to d/c therapy with thionamides (MMI and PTU)?

Answer 9

1) Agranulocytosis (0.5-6%)
2) Immunoallergic hepatitis (1.3%) (almost exclusive to PTU)

Question 10

What should you do if a relapse occurs after therapy with MMI or PTU?

Answer 10

Radioactive iodine (preferred over another course of anti-thyroid medication)

Question 11

What is the DOC for Graves’ disease, toxic autonomous nodules, and toxic multinodular goiters (MNGs)?

Answer 11

Radioactive iodine I-131

Question 12

What has an absolute contraindication in pregnancy / lactation / planning pregnancy, thyroid cancer and inability to comply with radiation safety guidelines?

Answer 12

Radioactive iodine I-131

Question 13

True or false: Radioactive iodine I-131 has a much higher success rate within 6 months compared to MMI/ PTU

Answer 13

True

Question 14

For Radioactive iodine I-131, what are the guidelines to prevent exposure to family members?

(this is a test question)

Answer 14

1) Do not kiss, exchange saliva or share food/utensils x 5d
Wash dishes in a dishwasher (not by hand)
2) Avoid close contact with infants, young children (under 8 y/o), and pregnant women for 5 days
3) Do not breast-feed
4) Flush the toilet twice after urinating and wash your hands thoroughly
5) If you have a sore throat or neck pain, take acetaminophen
6) Contact your physician if you notice increased nervousness, tremulousness or palpitations

Question 15

What is the dose of I-131?

Answer 15

Single dose between 3 and 15 mCi is given orally

Question 16

What are 2 situations in which you might use iodides?

Answer 16

1) Prior to surgery
2) Thyroid storm

Question 17

List 2 iodides

Answer 17

1) Saturated Solution (SSKI)
2) Lugol’s Solution

Question 18

Give an example of an adrenergic beta blocker and list its dose

Answer 18

Propranolol
Initial dose: 20-40mg QID – titrated to effect on HR

Question 19

What are some alternatives to propanolol?

Answer 19

Nadolol as alternative; non-dihydro CCBs have been used when beta-blockers are contraindicated

Question 20

________ is the DOC during 1st trimester for Grave’s

Answer 20

PTU

Question 21

List 5 drugs used in thyroid storm

Answer 21

1) PTU
2) MMI
3) Propranolol
4) Methylprednisolone
5) Hydrocortisone

Use 1 from each category; use higher doses than normal

Question 22

Suppression of thyroid hormone synthesis and secretion:
What is the thioamides of choice/ DOC for thyroid storm? What is the loading dose?

Answer 22

Propylthiouracil (PTU); 1 gram

Question 23

List 2 drugs that may cause secondary hypothyroidism

Answer 23

Lithium, amiodarone

Question 24

What is the preferred DOC for overt hypothyroidism?

Answer 24

T4 only/ Levothyroxine

Question 25

Levothyroxine (T4) may take ____min before _______________ / other medications or at bedtime post three hours from last meal

Answer 25

60; breakfast

Question 26

Levothyroxine: For exam purposes, we will use an IV:PO ratio of what?

Answer 26

0.75:1

Question 27

Hypothyroidism Levothyroxine Dosing (oral): What is the most common initial therapy dose?

Answer 27

Older adults > 50 years old: 50 mcg/day

Question 28

1 grain of Armour Thyroid, Nature Thyroid (T3 & T4) = _________mcg levothyroxine (test Q)

Answer 28

100mcg

Question 29

Subclinical or mild hypothyroidism: What is treatment driven by?

Answer 29

Symptoms

Question 30

What is the initial treatment for myxedema coma

Answer 30

1) IV bolus levothyroxine 300 – 500 mcg; 2) IV 75-100 mcg/day until transition to oral therapy 3) IV hydrocortisone 100mg q 8 hours should be given until coexisting adrenal suppression is ruled out

Question 31

What is the first line treatment for hyperthyroidism through the first trimester?

Answer 31

PTU (through week 16)

Question 32

_________________________ must be considered in EVERY patient with depression

Answer 32

Hypothyroidism