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Pharmacology Unit 5 > Thyroid Pharm > Flashcards

Flashcards in Thyroid Pharm Deck (32)
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1

Who is most likely to suffer from a thyroid disorder: men or women; young or old?

Older women

2

What is the precursor molecule of thyroid hormones?

tyrosine

3

A defect in the sodium-iodide transporter would lead to which thyroid disorder?

Hypothyroidism

4

What enzyme iodinates thyroglobulin?

thyroid peroxidase

5

Thyroxin is bound to what protein in the blood?

Thyroxin-binding globulin (TBG)

6

Is T3 of T4 the ligand for the thyroid hormone receptor?

T3

7

Symptoms of hypothyroidism

fatigue, weight gain, sensitivity to cold, goiter, muscle weakenss, constipation

8

What is Hashimoto's thyroiditis?

Autoimmune disease with production of antibodies against thyroid peroxidase, Na-iodide symporter, thyroglobulin, or TSH receptor

9

What is myxedema?

severe form of hypothyroidism mostly in adult women

10

What is cretinism?

Infancy hypothyroidism leading to mental retardation and dwarfism

11

What are the two main goals of thyroid hormone replacement therapy?

(1) to replace the function of the thyroid gland; (2) to prevent further growth of thyroid tissue

12

Synthetic thyroid hormones (3)

levothyroxine sodium (T4); liothyronine sodium (T3); Liotrix (T3+T4)

13

Which synthetic thyroid hormone drug is the preferred treatment for hypothyroidism and why?

Levothyroxine sodium (T4); longer half life and can be effectively converted to T3 in peripheral tissues

14

How long does is take for the peak therapeutic effect of levothyroxine sodium?

3-4 weeks

15

What are the benefits to using liothyronine sodium?

IV formulation can be used in acute emergencies; reaches peak levels in 2-4 hours after oral administration; eliminated rapidly (half-life= 1 day)

16

What are the disadvantages to using liothyronine sodium?

less stable, more costly, transient high levels of T3 in the serum

17

What are some precautions to consider when giving someone hormone replacement therapy?

If they have cardiovascular disease or are pregnant (cretinism)

18

Symptoms of hyperthyroidism

heart palpitations, weight loss, nervousness, sweating, diarrhea, insomnia

19

Number one cause of hyperthyroidism

Grave's disease: autoimmune disease consisting of thyroid-stimulating antibodies that activate thyrotropin receptor on thyroid cells

20

Other causes of hyperthyroidism

nodular goiter, thyroiditis, thyroid cancer

21

Typical lab findings in hyperthyroidism

TSH decreased; T3+T4 increased

22

4 hyperthyroid treatment strategies

(1) subtotal thyroidectomy + T4; (2) irradiate thyroid + T4; (3) inhibit thyroid peroxidase; (4) interfere with thyroid hormone activation of symp nervous system

23

3 drugs that inhibit thyroid peroxidase (antithyroids)

Propilthiouracil, methimazole, carbimazole

24

Which antithyroid drug has an active metabolite?

Carbimazole's active metabolite is Methimazole

25

Severe side effects of antithyroid drugs

agranulocytosis, hepatitis, lupus-like syndrome

26

Which antithyroid drug, Propylthiouracil or Methimazole, has a lesser chance of agranulocytosis and a shorter half-life?

Methimazole

27

Which antithyroid drug has a high risk of transferring across the placenta in pregnant women?

Methimazole

28

How long does it take for the effects of radioactive iodine therapy to be seen?

4 weeks

29

What is the indication for Radioiodine therapy?

Relapsed hyperthyroidism after antithyroid drug therapy

30

What is the contraindication to radioiodine therapy?

Pregnancy-radiation can effect fetus; also passes in breast milk so should be not given to women breast-feeding