Thyroid Flashcards
Free T4
active form as most is bound to protein
What is myxedema coma?
when hypothyroidism decompensates’ life threatening emergency IV thyroid hormone should be administered
How often should free T4 and TSH be checked in hypothyroidism
every 6 to 8 weeks until normalized then 6 months later then yearly
what drugs are associated with causing hypothyroidism?
amiodarone interferons llithium nitroprusside TKIs (sunitinib)
levothyroxine is a pregnancy ___
A; increases of 30 to 50% may be necessary during pregnancy
when should thryoid hormone replacement be taken?
first thing in the morning; empty stomach at least 30 mins before breakfast
What can be taken after exposure to radiation to prevent an accumulation of radioactive iodine?
potassium iodide
liothyronine
T3
dessicated thyroid
T3 and T4 Armour Thyroid; dosed in grains
How is levothyroxine dosed initially?
in patients > 50 or in patients <50 with underlying cardiac diseasestart at 50mcg/d
in patients >50 with cardiac disease what is the start dose of levothyroxine
start at 12.5mcg/ day; titrate every 4 to 8w to 25mcg
what is the usual replacement dose of levothyroxine approxiamately?
0.5mcg/kg/d for elderly; 1.7 mcg/kg/d <50
What SEs are common with thyroid replacement?
should be none; counsel patients on sx of hyperthyroidism (increased HR tachycardia weight loss irritability)
What is the IV:PO ratio for levothyroxine?
1:2
What should be seperated from levothyroxine by 4 hours?
aluminum calcium cholestyrimine iron mg multivitamines (ADEK) folate orlistat sevelamer sodium ALL decrease absorption of levopolystyrine sucralfate