Thyroid Disorders

Question 1

Levothyroxine counselling

Answer 1

Signs of a dose too high: Sweating, heat intolerance inc HR, palpitations, inc appetite, rapid unexpected weight loss, inc risk of fractures in elderly

Signs of dose too low: fatigue, cold intolerance and constipation

1h before food
2h before or 4h after calcium
6h from iron

Question 2

_______ supplements may interfere with thyroid tests; discontinue supplements at least ___ hours prior to testing.

Answer 2

Biotin
48 h

Question 3

Generally, it takes ______ to attain a new
steady state after dosage adjustments for levothyroxine

Answer 3

6 weeks

Question 4

Women with known hypothyroidism who are taking thyroid hormone replacement therapy should be advised to:

Answer 4

increase their thyroid hormone dose by 2 extra tablets
per week immediately following a positive pregnancy test. Further dose adjustment should be based on TSH levels

Question 5

Hashimoto thyroiditis

Answer 5

most common cause of hypothyroidism; high anti-TPO

Question 6

Grave’s disease

Answer 6

most common cause of hyperthyroidism

Question 7

Methimazole and propylthiouracil decrease the

Answer 7

production of thyroid hormones

Question 8

AE for methimazole & propylthiouracil

Answer 8

allergy, rash, agranulocytosis and, rarely, hepatotoxicity (less common w methimazole) and nephrotoxicity

Question 9

other medications often used in hyperthyroidism

Answer 9

Beta-blockers - reduce sx of androgenic excess
Iodine Lugol’s solution - blocks thyroid hormone production
Corticosteroids - lower T3
Selenium - helps orbitopathy (eyes)

Question 10

hyperthyroidism pregnancy considerations

Answer 10

while methimazole is most commonly used since it has lower risk of hepatotoxicity, propylthiouracil is preferred in 1st trimester to avoid congenital abnormalities

Question 11

methimazole or propylthiouracil monitoring when initiating

Answer 11

rare s/e of neutropenia can occur in 1st 90 days - report any infections to dr