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Pharmacology Unit 5 > Thyroid Pharm > Flashcards

Flashcards in Thyroid Pharm Deck (32)
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1
Q
Who is most likely to suffer from a thyroid disorder: men or women; young or old?
A
Older women
2
Q
What is the precursor molecule of thyroid hormones?
A
tyrosine
3
Q
A defect in the sodium-iodide transporter would lead to which thyroid disorder?
A
Hypothyroidism
4
Q
What enzyme iodinates thyroglobulin?
A
thyroid peroxidase
5
Q
Thyroxin is bound to what protein in the blood?
A
Thyroxin-binding globulin (TBG)
6
Q
Is T3 of T4 the ligand for the thyroid hormone receptor?
A
T3
7
Q
Symptoms of hypothyroidism
A
fatigue, weight gain, sensitivity to cold, goiter, muscle weakenss, constipation
8
Q
What is Hashimoto's thyroiditis?
A
Autoimmune disease with production of antibodies against thyroid peroxidase, Na-iodide symporter, thyroglobulin, or TSH receptor
9
Q
What is myxedema?
A
severe form of hypothyroidism mostly in adult women
10
Q
What is cretinism?
A
Infancy hypothyroidism leading to mental retardation and dwarfism
11
Q
What are the two main goals of thyroid hormone replacement therapy?
A
(1) to replace the function of the thyroid gland; (2) to prevent further growth of thyroid tissue
12
Q
Synthetic thyroid hormones (3)
A
levothyroxine sodium (T4); liothyronine sodium (T3); Liotrix (T3+T4)
13
Q
Which synthetic thyroid hormone drug is the preferred treatment for hypothyroidism and why?
A
Levothyroxine sodium (T4); longer half life and can be effectively converted to T3 in peripheral tissues
14
Q
How long does is take for the peak therapeutic effect of levothyroxine sodium?
A
3-4 weeks
15
Q
What are the benefits to using liothyronine sodium?
A
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
Q
What are the disadvantages to using liothyronine sodium?
A
less stable, more costly, transient high levels of T3 in the serum
17
Q
What are some precautions to consider when giving someone hormone replacement therapy?
A
If they have cardiovascular disease or are pregnant (cretinism)
18
Q
Symptoms of hyperthyroidism
A
heart palpitations, weight loss, nervousness, sweating, diarrhea, insomnia
19
Q
Number one cause of hyperthyroidism
A
Grave's disease: autoimmune disease consisting of thyroid-stimulating antibodies that activate thyrotropin receptor on thyroid cells
20
Q
Other causes of hyperthyroidism
A
nodular goiter, thyroiditis, thyroid cancer
21
Q
Typical lab findings in hyperthyroidism
A
TSH decreased; T3+T4 increased
22
Q
4 hyperthyroid treatment strategies
A
(1) subtotal thyroidectomy + T4; (2) irradiate thyroid + T4; (3) inhibit thyroid peroxidase; (4) interfere with thyroid hormone activation of symp nervous system
23
Q
3 drugs that inhibit thyroid peroxidase (antithyroids)
A
Propilthiouracil, methimazole, carbimazole
24
Q
Which antithyroid drug has an active metabolite?
A
Carbimazole's active metabolite is Methimazole
25
Q
Severe side effects of antithyroid drugs
A
agranulocytosis, hepatitis, lupus-like syndrome
26
Q
Which antithyroid drug, Propylthiouracil or Methimazole, has a lesser chance of agranulocytosis and a shorter half-life?
A
Methimazole
27
Q
Which antithyroid drug has a high risk of transferring across the placenta in pregnant women?
A
Methimazole
28
Q
How long does it take for the effects of radioactive iodine therapy to be seen?
A
4 weeks
29
Q
What is the indication for Radioiodine therapy?
A
Relapsed hyperthyroidism after antithyroid drug therapy
30
Q
What is the contraindication to radioiodine therapy?
A
Pregnancy-radiation can effect fetus; also passes in breast milk so should be not given to women breast-feeding
31
Q
What is the main side effect of radioiodine therapy?
A
hypothyroidism
32
Q
When are beta-adrenergic drugs used?
A
to control symptoms of hyperthyroidism such as anxiety, palpitations, tremor