HYPOTHYROIDISM

Question 1

Which major side effect is observed in 10% in patients with hypothyroidism from Hashimoto’s?

Answer 1

Pernicious anemia

Question 2

What is primary hypothyroidism? Secondary?

Answer 2

Primary -> thyroid cant make hormones

Secondary -> thyroid isnt being stimulated by pituitary

Question 3

What is the most common cause of spontaneous hypothyroidism in adults in the US?

Answer 3

Hashimoto’s disease

Question 4

In hypothyroidism, what are the levels of TSH like? T3 and T4? (high, low)

Answer 4

High TSH

Low T3 T4

Question 5

What are two main drugs that can induce hypothyroidism?

Answer 5

Lithium - inhibits TSH

Amiodarone - can lead to hypo/hyper

Question 6

What are some distinguishing factors of Armour Thyroid?

Answer 6

It is derived from pig thyroid glands

Grain dosing

Question 7

What are some distinguishing factors of Liothyronine?

Answer 7

It is synthetic T3

Short half life of 1.5 days

It is also available in IV formulation

It has disadvanatges with cardiac events

Question 8

What are some distinguishing factors of Liotrix?

Answer 8

It is synthetic T4 and T3 (4:1)

Question 9

What are some distinguishing factors of Levothyroxine?

Answer 9

It is T4

DOC

You should avoid therapeutic interchange

Question 10

Which drugs increase absorption of Levothyroxine?

Answer 10

Cholestyramine
Ciprofloxacin
Sucralfate
Oral bisphosphonates
Ferrous sulfate
Antacids (calcium salts)
PPI/H2 blocker

Question 11

Which drugs decrease absorption of Levothyroxine?

Answer 11

Rifampin
Anticonvulsants : CBZ, phenytoin, Phenobarbital
Sertraline

Question 12

What is the gold standard of monitoring hypothyroidism?

Answer 12

TSH levels

Question 13

How long should TSH levels be monitored after administration of medications?

Answer 13

Q4-8 weeks until euthyroid (6 weeks is okay too)

Question 14

With hypothyroidism, what are some drugs that might be affected due to the disease state?

Answer 14

Warfarin - decreases its clearance and increases INR
Insulin - slows metabolism of insulin
Digoxin - slows metabolism of digoxin
Opiods - slows metabolism of opiods

Question 15

What are some counseling points for taking Levothyroxine?

Answer 15

Take on an EMPTY stomach 30-60 minutes before breakfast or other meds

Take at the same time every day

The brand matters

Pills can be crushed and suspended in water

It might take a few weeks to see effects

Question 16

What considerations do you make for pregnant women?

Answer 16

Need to increase dose because of fetus demand of thyroid hormones

Revert back to normal dosing after birth

Question 17

Which population is subclinical or mild hypothyroidism prevelant? Do they have side effects? What about their T3 + T4 along with TSH?

Answer 17

Women and old people

SE: little to none

T3 + T4 are normal but TSH can be elevated