Drugs for Thyroid Disease Flashcards
Posterior Lobe produces?
ADH and Oxytocin
where is the thyroid located?
anterior of the neck
what do thyroid hormones regulate?
oxygen use & basal metabolic rate, cellular metabolism and growth & development
Calcitonin function
helps to regulate calcium homeostatsis
Order of thyroid release starting from the hypothalamus to the release of thyroid cells
hypothalamus thyroid releasing hormone Anterior pituitary Thyroid stimulating hormone thyroid t3 & t4
chronotropic
increasing the rate of occurrence (example heart beat)
catabolic
complex substances are converted into smaller ones
TSH is used to screen for what?
hypo and hyperthyroidism
free t4 and free t3 can confirm which diagnosis?
hyper or hypothyroidism
hypothyroid s/s
pale puffy face, cold dry skin, brittle hair, lethargy, low HR and temp
hyperthyroid s/s
heart palpitations, fatigue, heat intolerance, irritability
myxedema is seen in hypo or hyperthyroid?
hypo
cretinism in infancy is the cause of hypo or hyper in pregnancy?
hypo
what can cause hypothyroidism?
removal of thyroid, malfunction of thyroid, Hashimoto disease, not enough iodine
During pregnancy, hypothyroidism can cause what problems in the baby during the first trimester
permanent neuropsychologic deficits
is hypothyroidism permanent or transient in infants?
it can be both
Levothyroxine (t4) and Liothyronie (t3) are meds for hypo or hyper?
hypo
Graves disease is a form of hyper or hypo?
hyper
expohthalmos is an effect of which disease?
graves/ hyper
how do you treat hyperthyroidsm?
surgery, beta blockers (to manage symptoms), nonradioactive iodine,
cure for toxic nodular goiter (Plummer disease)? and is it a cause of hyper or hypothyroid?
remove thyroid/hyper
Thyrotoxic crisis (thyroid storm) is caused by hypo or hyperthyroid?
hyper
s/s of Thyrotoxic crisis (thyroid storm)
hyperthermia (105 or higher), restlessness, severe tachycardia, hypotension
treatment of thyrotoxic crisis (thyroid storm)
methimazole, beta blocker, sedation, cooling, steriods, IV fluids
How long does Levothyroxine (Synthroid) take to work?
1 month
Levothyroxine (Synthroid) side effects
tachycardia, angina, tremors
which drugs does Levothyroxine (Synthroid) interfere with and how?
increases effects of warfarin and decreases synthroid absorption
H2 blockers, PPIs will reduce Synthroid absorption
decreases insulin absorption so watch BS levels
When should you give an H2 blockers, or PPIs with Levothyroxine (synthroid)?
4 hours apart
before starting treatment of hypothyroidism what do you need to restore first?
adrenal function
hypothyroidism atypical presentation in geriatrics
CHF
how is absorption affected with geriatrics with thyroid medications?
its increased so start low
when can therapy stop for congenital hypothyroidism?
4-8 weeks after the 3rd birthday
children and pregnancy may require higher or lower doses of thyroid replacement?
higher
Is thyroid replacement ok in pregnancy>
yes, minimal excretion in breast milk
when should you be careful about using thyroid replacement therapies?
after an MI, untreated thyrotoxicosis, adrenal insufficiency, hypersensitivity
what happens if there is adrenal insufficiency and thyroid replacements are given?
it will precipitate crisis
What do you do if patient has toxicity from thyroid drugs?
DC for 5-7 days then restart at a low dose
when should you evaluate thyroid therapy during pregnancy?
8 weeks and 6 month gestation
after euthyroid has been achieved with thyroid replacement, how often do you evaluate levels?
annually
How often do you evaluate thyroid levels until euthyroid is achieved?
6-8 weeks
which thyroid disease causes a goiter?
graves (hyper)
first line drug for hyperthyroidism
methimazole (Tapazole)
which hyperthyroid drug does not destroy existing store of thyroid hormone, does not cause liver damage associated with PTU?
Methimazole (Tapazole)
How long after taking Methimazole (Tapazole), does it take to reach a euthyroid state?
3-12 weeks
side effect of Methimazole (Tapazole)
Agranulocytosis (decrease in the number of infection fighting granulocytes)
when do you use Methimazole (Tapazole) (4)
- graves disease
- in conjunction with radiation therapy until radiation therapy becomes efficient
- when you need to supress thyroid hormones in order to prepare for thyroid surgery
- thyrotoxic crisis
Propylthiouracil (PTU) is used for hyper or hypo?
hyper
Propylthiouracil (PTU) action
inhibits thyroid hormone synthesis
how long does Propylthiouracil (PTU) take to work?
6-12 months
Propylthiouracil (PTU) adverse effects
can cause severe liver damage
Propylthiouracil (PTU) vs Methimazole
PTU has shorter half life, PTU can cause severe liver damage, methimazole worse for pregnancy, PTU clocks T4 to T3 conversion
mild hyperthyroid dosing for Methimazole
15mg/day in dividided doses q8 hrs
mild hyperthyroid dosing for PTU
300-400mg/day in divided doses q8-12 hr
Moderate hyperthyroid dosing for Methimazole
30-40mg/day
severe hyperthyroid dosing for methimazole
60mg/day
severe hyperthyroid dosing for PTU
400 mg/day
why is nonradioactive iodine used
to suppress thyroid function in preparation for thyroidectomy
adverse effects of nonradioactive iodine
brassy taste, burning sensation in mouth, sore teeth, frontal headache, coryza, salivation
Thyroid suppressants have what kind of effect on warfarin?
its decrease
what types of foods should hyperthyroid patients avoid?
foods high in iodine, seafood, iodized salt
If TSH is elevated during thyroid suppressant therapy what do you need to do?
lower dose
how often do you monitor thyroid suppressant therapy in an infant? 1-3 year old? >3 years old?
2 months, 2-3 months, 3-12 months
what is the outcome evaluation of thyroid suppressant therapy based on?
TSH and free T4 levels
