Thyroid Flashcards
what is the function of the thyroid hormone
growth, development, function, maintenance, metabolism, body temp, heart rate
what are 3 hyperthyroid diseases
Grave’s disease
Muti-nodular toxic goiter (plummers disease)
Thyrotoxicosis
what are 2 types of primary hypothyroism
hasimotos thyroiditis
Iatrogenic
what are secondary causes of hypothyrodism
pituitarty disease
hypothalamic disease
what drugs decrease secretion of TSH
dopamine
glucocorticoids
octreotide
what drugs decrease thyroid hormone secretion
lithium
Iodine and Iodine preparations
Radiocontrast dyes
amiodarone
hyperthyroid epidemiology
between 40-60
more common in women
what is the treatment for hyperthyroidism
anti-thyroid meds radio active iodine thyroidectomy symptomatic treatment beta-blockers
what are anti-thyroid medications
methimazole-1st line
propylthiouracil (PTU)-thyroid storm 1st trimester
what is drug of choice for most patients with hyperthyroidism
methimazole
when is PTU best used for
pregnancy
thyroid storm
what are predictors of remission
small goiter
mild disease
low or neg thyroreceptor antibody titer
how do thioamides work
inhibit thyroid hormone synthesis
how does PTU work
inhibits peripheral T4-T3 conversion with in hours of dosin
which of the thioamides is compatible with breast feeding
methimazole
what are some serious side affects with thioamides
agranulocytosis
hepatotoxicity
how do iodides work
inhibit thyroid hormone release
decrease thyroid hormone synthesis
decrease gland vascularity
how are iodides used in thyroid disease
reduce vascularity prior to thyroid surgery
prepare pts with graves disease for surgery
decreased thyroiodine accumulation in thyrotixic crisis
prevent thyroid uptake of radioactiv iodine
what are some iodide products
saturated solution SSKI
Lugols
When to use iodide products in intitial dosing
50-500mg in water or juice
10-14 days prior to surgery
as adjunct to RAI
what are adverse effects of iodide drugs
rash, GI upset paresthesia, immune rxn salivary gland swelling burning throat metallic taste sore teeth or gums cold symptoms
when is lithium used in treatment
adjunct to thoamides
decreased radioactive iodine does to cure graves disease
what are adverse effects with Lithium
tremors, polyuria, renal failure, seizure, arrhythmia, bradycardia, suicide
DO NOT USE
when are beta blockers used
symptomatic treatment of palpitations, tachycardia, tremor, heat intolerance
Thyrotoxicosis
preoperatively adjunct to potassium iodide, radioactive iodine or antithyroid drugs for graves disease
thyroid storm
thyroiditis
when is radioactive iodine contraindicated
pregnancy
lactation
thyroid cancer
antithyroid meds
when do you used radioactive iodine
surgical removal of body tissue for grave disease
women planning pregnancy greater than 4-6 months in future
patients with increased surgical risk prior to neck surgery
what are the benefits of radioactive iodine
well tolerated
low risk of thyroid storm
what are side effects of radioactive iodine
dysphagia
thyroid tenderness
what causes thyroid storm
stress from surgery
anesthesia, thyroid manipulation in patients
abrupt d/c of antithyroid meds
what are symptoms of thyroid storm
high fever 103> tachchardia A-fib CHF Tachypnea Dehydration N/V coma
what is the treatment for thyroid stome
identify cause and treat cause anti-thyroid meds (give before iodine) inorganic iodine supportive care beta blockade
when would you use esmolol in a patient
in heart failure or patients who can not take per oral meds
what is the cause of subclinical hyperthyroidism
low TSH
amiodarone induced
how do you treat subclinical hyperthyroidism
initiante TSH
what causes hypothyroidism
anti-thyroid meds, PTU, methimazole
what are some complications with subclinical hypothyroidism
TSH above normal levels
myxedema (associated with coronary artery disease)
myxedema coma
Treat w/ TSH>10mIU/L
what are signs of hypothyroidism
dry skin, cold intolerance, weight gain, constipation, weakness, lethargy depression
what are signs of hypothyroidism
coarse skin and hair cold or dry skin periorbital puffiness bradycardia slow hoarse speech
what are laboratory findings for hypothyroidism
increased cholesterol, LDH, AST, ALT,CPK
what are thyroid supplement options
desiccated thyroid and thyroglobulin
levothyroxine
liothyronine
liotrix
what is first line for hypothyroidism
synthetic L-thyroxine (synthroid, levoxyl)
what are the pharmocokinetics like fore the l-thyroxine
40-80% bioavailibility better with fasting decreases with fiber 99%protein bound 80% hepatic metabolism
what decreases absorption of l-thyroxine
cholestyramine
calcium carb
sucralfate
soybean fiber food
how should levothyroxine be given orally, IV, feeding tube
30min prior to breakfast 4 hours after last meal
use 70-50% or oral dose for IV
create water suspension wait at least 1 hr to restart feeding
What are the disadvantages of Liothyronine T3
higher cardiac effects
more expensive
hard to monitor lab values
what are the disadvantages of liotrix
high cost, lack of therapeutic rationale
What is euthyroid essential for
normal neurocognitive development in fetus
What should you do with women who are being treated for hypothyroidism?
increased rate of metabolsims for thyroid hormone/transplacental transport
so dose of levothyroxine should be increased by 30%
what percent of pts attain remission after initial therapy
20-30%
how long should treatment be continued for?
12-18 months then taper or d/c if euthyroid at that time
when should a person stop anithyroid meds
when they have normal TSH, FT4, T3 1 year after
when should a patient who is in remission follow up
retest every 1-3 months for 6-12 months after initial remission and d/c methimazole
when should you start monitoring FT4 level
4 months after start of therapy
then every 4-8 weeks until normalized then every 2-3 months
Which medication of the thiomaides do you need to do LFTS on
PTU with sign of liver damage, jaundice, joint pain, ab pain, light stool, dark urine
what is the half life of RAI
5 days
