Hyperthyroidism - Low/Med Priority

Question 1

What is the most common cause of hyperthyroidism?

Answer 1

Graves disease
-thyroid receptor stimulating immunoglobulins stimulate TSH receptor on thyroid gland
-overproduction of thyroid hormone

Question 2

What is a risk factor for Graves disease?

Answer 2

smoking

Question 3

Asides from Graves, what are other potential causes of hyperthyroidism?

Answer 3

toxic nodule or multi-nodular goitre
-thyroid growth and acitivity of nodules cause increase in overall hormone production
subactue (viral)/acute (bacterial) thyroiditis
-infection of thyroid gland
-leakage of thyroid gland

Question 4

What is the clinical presentation of hyperthyroidism?

Answer 4

increased metabolic activity
-nervousness
-perspiration
-palpitations
-hand tremors
-anxiety
-diarrhea
-heat intolerance
-weight loss
-insomnia
-increased appetite
-eyelid lag
-tachycardia
-hyperreflexia
-warm/moist skin
-goitre
-nodules
-increased risk of afib

Question 5

What are the complications of hyperthyroidism?

Answer 5

Graves ophthalmopathy (exophthalmos)
thyroid storm

Question 6

What is Graves ophthalmopathy?

Answer 6

increase in extraocular muscle volume and retro-orbital connective and adipose tissues
increase fluid content and pressure in the eye
-forward eye displacement

Question 7

What is a thyroid storm?

Answer 7

life-threatening with severe thyrotoxicosis
-HR, BP and temp can reach dangerously high lvls
-excessive thyroid hormone production

Question 8

What is the treatment for thyroid storm?

Answer 8

PTU
beta blockers
corticosteroids
Lugols solution

Question 9

Which drugs can worsen thyroid storm?

Answer 9

NSAIDs
-displaces thyroid hormones from globulins

Question 10

What are some drug causes of hyperthyroidism?

Answer 10

levothyroxine, liothyronine
lithium
amiodarone
interferon alpha
TKI

Question 11

What are the lab values seen in hyperthyroidism?

Answer 11

decreased TSH
increased fT4

Question 12

What are the lab values seen in subclinical hyperthyroidism?

Answer 12

normal fT4
low TSH

Question 13

What are the goals of therapy for hyperthyroidism?

Answer 13

achieve and maintain a euthyroid state
prevent hyperthyroidism-related complications
manage the signs and symptoms of hyperthyroidism
prevent drug-related AE

Question 14

What are the non-pharmacological measures for hyperthyroidism?

Answer 14

thyroid surgery
-nodules, large goitres, cancer
-medical therapy prior to surgery to create euthyroid state

Question 15

What is the MOA of radioactive iodine?

Answer 15

radiation damages thyroid tissue

Question 16

What is a contraindication of radioactive iodine?

Answer 16

pregnancy and breastfeeding

Question 17

What does radioactive iodine worsen?

Answer 17

Graves opthalmopathy

Question 18

What are the thionamides?

Answer 18

methimazole
propylthiouracil

Question 19

What is the MOA of the thionamides?

Answer 19

MMI:
-inhibits corporation of iodine to tyrosine residues
PTU:
-same as MMI + inhibits peripheral conversion of T4 –> T3

Question 20

What are the common AE of thionamides?

Answer 20

arthralgia
rash
nausea
can improve in 4 wks, divided doses can help nausea

Question 21

What are the rare AE of thionamides?

Answer 21

edema
bone marrow suppression
agranulocytosis
hepatic/autoimmune effects

Question 22

What is a contraindication of methimazole?

Answer 22

1st trimester of pregnancy

Question 23

Which thionamide has higher risk of hepatotoxicity and agranulocytosis?

Answer 23

PTU

Question 24

When should a patient stop taking their thionamide?

Answer 24

if they experience fever, jaundice, or a rash

Question 25

What are the drug interactions with thionamides?

Answer 25

clozapine (agranulocytosis) digoxin warfarin

Question 26

Which thionamide is preferred and why?

Answer 26

MMI -faster reversal of hyperthyroidism -fewer side effects -longer duration of action

Question 27

Which thionamide can be used in children?

Answer 27

MMI -PTU has high risk of hepatotoxicity in children

Question 28

What are the key considerations with radioactive iodine and pregnancy?

Answer 28

after therapy, wait at least 6 months before conceiving women of childbearing age require a negative pregnacny test within 48hrs of receiving radioactive iodine radioactive iodine should not be given for 6-12 wks after cessation of breastfeeding

Question 29

How long is treatment with thionamides?

Answer 29

may be life-long -often treat until euthyroid for at least 12-18 months -if d/c, TSH/T3/T4 should be monitored q 2-3 mo x 6 mo followed by q 6-12 mo

Question 30

When is PTU used?

Answer 30

minor reactions to MMI who do not want definitive therapy with surgery/RAID

Question 31

Why is PTU preferred in thyroid storm?

Answer 31

inhibits conversion of T4 to T3

Question 32

What is the role for beta blockers in hyperthyroidism?

Answer 32

symptoms of hyperthyroidism

Question 33

Which beta blocker has the most evidence in hyperthyroidism?

Answer 33

propranolol

Question 34

Describe appropriate medication use for hyperthyroidism in pregnancy.

Answer 34

1st trimester: PTU preferred switch to MMI in 2nd trimester and continue during breastfeeding

Question 35

What are the risks of untreated hyperthyroidism in pregnancy?

Answer 35

increased risk of fetal loss

Question 36

What should occur after birth if a mother was treated with MMI or PTU?

Answer 36

newborn should be assessed for hypothyroidism

Question 37

Which beta blocker should be avoided in pregnancy?

Answer 37

atenolol -risk of smaller babies

Question 38

What should be done with hyperthyroidism prior to conception?

Answer 38

good control of thyroid levels

Question 39

During which trimesters of pregnancy might hyperthyroidism ameliorate?

Answer 39

2nd and 3rd

Question 40

What is the time to benefit of thionamides?

Answer 40

improvement in symptoms in 2-3 weeks peak effect may take 4-6 wks