THYROID Flashcards
how does the negative feedback loop work?
hypothalamus releases TRH > pituitary releases TSH > thyroid releases TH
once hypothalamus senses enough TH, will stop releasing TRH
graves disease labs
TRAb
in which group of patients is routine screening required
pediatrics and pregnant women
how do nsaids affect t4 level
NSAIDs can increase free T4 level
which drug has a boxed risk of hepatotoxicity
ptu
when to recheck t4 levels upon therapy initiation or modification
4-8 weeks
how does amiodarone affect thyroid function
contains iodide, `can cause rise or fall in t3 and t4 levels directly
3 potential adverse effects of excessive thyroid replacement
atrial fibrillation, osteoporosis,
sx of hyperthyroidism
which drug is teratogenic
carbimazole, but only avoid in 1st stage of preg.
what is the dose conversion of methimazole to ptu, and when should you recheck thyroid levels when changing drug
1:10
2 weeks later, then at 2 to 4 weeks interval
subclinical hypothyroidism (TSH, T4) / how to know when a pt is non adherent to levothy
elevated TSH, normal T4
subclinical hyperthyroidism (TSH, T4)
low TSH, normal T4
how to dose levothyroxine in young healthy adults
1.6mcg/kg/d
how to dose levothy in adults 50-60yrs of age without cvd
50 mcg per day
hypothyroidism (tsh, t4) and what antibodies
high tsh, low t4
TPO, ATgA
free t4 normal range
0.8-2.7
tsh normal range
0.4-4.2
how much increase of levothyroxine is needed in pregnant ladies
30-50%
when to treat subclinical hypothyroidism (in terms of TSH)
- TSH > 10
- TSH < 10
- with sx of hypothyroidism
- TPO present
- CVD history
how does ptu work
blocks thyroid hormone synthesis,
inhibits peroxidase enzyme system of thyroid
how does ptu regulate t4 and t3
inhibits peripheral conversion of t4 to t3
what should be used in first trimester of pregnancy, ptu or carbimazole
ptu
what is hashimoto’s disease caused by
thyroid gland failure cased by defects in suppressor T lymphocyte function
