HYPO- & HYPERthyroidism

Question 1

UNDERproduction of thyroid hormones → leads to:

Answer 1

1. bradycardia
2. poor resistance to cold
3. mental & physical slowing
4. in children → may cause mental retardation & dwarfism

Question 2

treatment of HYPOthyroidism: (thyroid hormones drug names)

Answer 2

1. levothyroxine (T4 = levaxin) → mostly used due to longer t1/2 & better tolerated in comparison
2. liothyronine (T3)
3. liothrix (T3/T4 combinations)

Question 3

thyroid hormones → indications:

Answer 3

1. substitution → replacement therapy
2. goiter → euthyreosis
3. to prevent dev. of hypothyroidism (after I-131, thyroid surgery, thyroid inflammation)

Question 4

thyroid hormones → side effects:

Answer 4

1. angina pectoris
2. heart attack
3. cardiac arrhythmias

Question 5

OVERproduction of thyroid hormones → leads to:

Answer 5

1. tachycardia or cardiac arrhythmias
2. body wasting
3. nervousness
4. tremor
5. heat intolerance

Question 6

HYPERthyroidism → causes:

Answer 6

1. Grave’s disease → most common cause!

2. can be caused by drugs → amiodarone (iodine-containing anti-arrhythmic drug), sorafenib, pilimumab

Question 7

HYPOthyroidism → causes:

Answer 7

1. usually a result from autoimmune destruction of thyroid gland (in ex. Hashimoto’s)
2. diagnosed by elevated TSH-levels
3. can be caused by drugs → lithium, amiodarone (iodine-containing anti-arrhythmic drug)

Question 8

treatment methods of HYPERthyroidism:

Answer 8

1. removal of parts/the whole thyroid gland → surgery → destruction with radioactive iodine → 131I (most pat. becomes HYPOthyroid after this treatment → require treatment with levothyroxine)
2. inhibition of thyroid hormone synthesis (thioamides)
3. blockade of hormone release → iodide (not useful in long-term therapy)
4. thyroid storm → give B-blockers & glucocorticosteroids

Question 9

inhibition of thyroid hormone synthesis → drug names of TPO (thyroid peroxidase) inhibitors:

Answer 9

1. propylthiouracil (PTU)

2. methimazole

Question 10

which TPO is indicated in pregnancy & breast feeding?

Answer 10

answer: propylthiouracil (PTU) → okay during 1st trimester

methimazole is TERATOGENIC, however both drugs cross the placenta

Question 11

TPOs → pharmacokinetics:

Answer 11

1. propylthiouracil (PTU) → half-life = 1,5h (2x/daily)

2. methimazole → half-life = 6h (1x/daily)

Question 12

TPOs → side effects:

Answer 12

propylthiouracil (PTU) → ass. with hepatoxicity & rarely agranulocytosis