Thyroid/Antithyroid Drugs Flashcards
What cells make T3/T4?
Follicular cells
What cells make calcitonin?
Parafollicular cells
What is the name of the transporter that take Na and iodide into the follicular cell on the basolateral membrane?
NIS
What is the name of the transporter that take iodide and brings it into the lumen of the follicular cell?
Pendrin
What turns iodide into iodine?
TPO
What brings MITs and DITs into the follicular cell on the apical membrane?
Megalin
What breaks down MITs and DITs in the follicular cells so iodide can be used again?
Intercellular deiodinase
What binds to T3/T4 to be transported in the blood?
Thyroid binding globulin (TBG)
What turns T4 into T3?
Peripheral deiodinase
Stimulation of what receptor on basilar membrane causes production of T3/T4 and follicular cell reproduction?
Stimulation of TSH receptor
What actions do thyroid hormone cause to heart, respiration’s, protein synthesis, body weight, blood glucose, bone and nervous tissue? What does it do to Na/K pumps?
positive chronotropic and inotropic effect Increases respiration’s Increases protein synthesis Decreases weight Increases BGL Increases bone growth Increases nervous tissue growth
Increases the number of Na/K pumps in the body
Pt with little to no nervous tissue can cause what? What can it lead to?
Cretinism
Lead to mental retardation
Why are the Sx of a pt w/ hypothyroidism(6)?
Cretinism Cold intolerance weight gain Lethargic Constipation Goiter Myxedema
What is myxedema? What condition is it associated with?
Coma caused by respiratory acidosis
What are the Sx of a pt w/ hyperthyroidism(7)?
Heat intolerance Weight loss Tachycardia Diarrhea Exophthalmos Goiter Increased BGL
What is exophthalmos? How is it caused?
Bulging eyes
Immune system attacks muscles and CT behind eye causing inflammation
How is goiter caused in hyperthyroidism? Hypothyroidism?
Hyperthyroidism-increase is TSI levels
Hypothyroidism-increase in TSH d/t feedback from low T3/T4
What deficiency can often cause goiter?
Iodine deficiency
What is the number 1 cause of hypothyroidism? What does it attack?
Hashimotos disease
Antibodies attack TPO and thyroglobulin
What edible substances can cause hypothyroidism?
Cabbage
How can tumors cause hypothyroidism?
Tumors can steal nutrients for TSH production
What can cause damage to follicular cells?
X-rays
Iodine deficiency
What is the number 1 cause for hyperthyroidism? How is it caused?
Graves’ disease
TSI stimulates TSH receptors to keep increasing T3/T4 w/o a negative feedback response
Where does a primary thyroid malfunction occur?
In the thyroid gland itself
What does a pituitary malfunction occur?
In the anterior pituitary
Where does a hypothalamic malfunction occur?
In the hypothalamus
What is armour thyroid from? What type of thyroid hormones does it contain?
Porcine-derived
Contains both T3/T4
What is the goal for TSH levels when a pt is on HRT? How big of a dose of T3/T4 should be given to lower TSH levels?
Goal is to have TSH levels at lower end of normal range
Give largest dose of T3/T4 to decrease TSH levels
What is euthyroidism?
Thyroid levels are in normal range
When on HRT, when should medication be taken, why?
Before breakfast because the food makes HRT less absorbed
Out of T3 and T4, which medication has a quicker onset and shorter duration?
T3
What is a black box warning for HRT? Why?
Contraindicated for pt w/ obesity
Can lead to HF
When must a pt be taking insulin w/ their thyroid medication?
When taking synthroid
What are the 3 forms of Tx for hyperthyroidism?
Anti thyroid drugs
Radiation
Surgical removal
Why should a pt taking thyroid drugs, take the medication once daily in the morning?
Decrease chances of insomnia
What Sx should be reported for a pt on thyroid medication(2)?
Chest pain
Heart palpitations
How long does it take for therapeutic effects to occur when taking thyroid medication?
Several weeks (3-4wks)
What must be done with HRT dosage to keep TSH levels at lower end of normal range?
Adjust dosage every 4 weeks
What must DM pt taking thyroid medication do to their hypoglycemic medication?
Increase dosage
What can happen to the baby if a mother is experiencing hypothyroidism while pregnant?
Cretinism(mental retardation)
What should antithyroid medications be given w/? What time of day?
Food
Same time each day
True or false: you can stop taking antithyroid medications abruptly?
False
What decreases the effectiveness of antithyroid medications? What are some examples?
Eating foods high in iodine
Seafood
Soy sauce
Tofu
Iodized salt
