Thyroid Therapy Lecture PDF

Question 1

Thyroid hormone mech of action

Answer 1

• T3, the only active form enters the cell and binds specific receptors located in the cell’s nucleus
• induces transcription of specific DNA segments which ultimately results in altered protein synthesis in the cell

Question 2

Myxedema coma treatment

Answer 2

May use T3 to get result more quickly

Question 3

Hypothyroidism during pregnancy treatment

Answer 3

Damage done to first trimester when fetus unable to produce hormones on own, must be diagnosed early and treated with levothyroxine

Question 4

Exopthalmos is not caused by increased level of thyroid hormone (or TSI’s), and thus…

Answer 4

….correction of thyroid hormone levels does not cure it

Question 5

Thyroid storm

Answer 5

May occur if levels of thyroid hormones are extremely high characterized by hyperthermia, tachycardia, weakness, coma and heart failure

Question 6

TSI’s

Answer 6

Thyroid stimulating immunoglobins, produced by autoimmune process and can stimulate TSH receptors on the thyroid gland

Question 7

Plummer’s disease/toxic nodular goiter

Answer 7

Recult of thyroid adenoma that clinical manifestts similar to graves disease but without exopthalmos, requires surgery and radiation

Question 8

Factitious hyperthyroidism

Answer 8

Exogenous hyperthyroidism due to the secret ingestion of thyroid hormone (usually for weight loss)

Question 9

Thyroid hormone should not be used to treat obesity because…

Answer 9

….it accelerates metabolism and promotes weight reduction only if dosage is high enough to establish pathologic condition (thyrotoxicosis)

Question 10

Levothyroxin administration route

Answer 10

Almost always PO on an empty stomach

Question 11

Exogenous thyroid hormone takes ___ to see activity, this is beneficial because it keeps levels ___

Answer 11

1 month to reach steady state, steady between doses

Question 12

Goal of thyroid hormone replacement is to return ___ to physiologic range

Answer 12

TSH level (between .5-5 uU/mL

Question 13

Extra concern of thyroid replacement therapy must be taken in those with comorbid ___

Answer 13

CV disease

Question 14

Prolonged hyperthyroidism can generate predisposition to these 4 things

Answer 14

• cardiac arrhythmia
• tachycardias
• angina
• MI

Question 15

Why should patients be maintained on the same brand name or generic levothyroxine product (lest they switch and have to retest serum TSH in 6 weeks and re-adjust dosage)?

Answer 15

Because bioavailability varies greatly among levothyroxine products

Question 16

Desiccated thyroid (Thyroid USP/armour thyroid)

Answer 16

Obsolete treatment for hypothyroidism only still used in those who have been on it for years derived from porcine, has higher T3:T4 ratio which can lead to fluctuating levels of T3

Question 17

Propylthiouracil (PTU) function and ADR’s (3)

Answer 17

• Used alone as sole source of treatment in graves disease or employed as adjunct to radiation therapy
• Agranulocytosis, hypothyroidism, liver injury (sudden onset)

Question 18

Methimazole (tapazole) function

Answer 18

Acts similar to PTU but does NOT affect conversion of T4 to T3 in periphery,

Question 19

Lugol’s solution function and ADR’s (3)

Answer 19

• Strong iodine that causes paradoxical suppression of thyroid
• Brassy taste, burning sensation in mouth and throat, salivations

Question 20

Sodium iodide

Answer 20

Used in acute management of thyrotoxic crisis

Question 21

Potassium iodide (thyro-block)

Answer 21

PO to protect thyroid in event of radiation emergency (such as a nuclear accident) that prevents uptake of radioactive iodide preventing harm to thyroid gland

Question 22

Radioactive iodine 131 I

Answer 22

Radioactive isotope of stable iodine to produce clinical remission in hyperthyroid patients by destroying the gland without damaging surrounding tissue