Thyroid disorders Flashcards
which has a longer half life ? t4 or t 3?
T4
which can have a negative feedback w/ TSH to decrease its production? t4 or t3?
T4
in hyperthyroidism, levels of T4 vs TSH? (diagnosis)
t4 is high, tsh is low due to negative feedback
in hypothyroidism, levels of t4 vs tsh? (diagnosis)
t4 is low, tsh is high
sx of hypothyroidism ?
fatigue weight gain (slow metabolism dry skin hoarsness coarse or loss of hair memory and mental impairment myalgias HLD depression
what is the most common type of hypothyroidism?
Hashimoto’s: autominue attack of the thyroid gland
what are the two most common agents that can cause hypothyroidism?
lithium and amiodarone
what is a typical dose for starting levothyroxine in an elderly patient?
12.5 to 25 mcg daily
what are the consequences of overdosing the levothyroxine?
causes atrial fibrillation and fractures
when you start levothyroxine, how often should you mx levels?
q 6-8 weeks until normal levels, then in 6 mod, then every year
about how much should you increase the dose of levothyroxine if a women becomes pregnant?
30-50% throughout the pregnancy. Even several months after birth of the child
cytomel
liothyronine
triostat
liothyronine
armour thyroid
t3 and t4
how should patients take their thyroid hormone?
in the AM on an empty stomach 30 minutes before eating because its absorption is decrease w/ fiber, calcium , iron or other supplements
synthorid
t4
levothroid
t4
levoxyl
t4
what do you do if a patient switches brands of thyroid hormone?
make sure to tell about signs and symptoms and check levels in 6-8 weeks
what dose to start patients for t4 <50 years old?
1.7 mcg/kg/day
what dose to start in elderly adults > 50 years old for t4?
0.5 mcg/kg/day usually 12.5 or 25mcg
pregnancy category for levothyroxine?
A!!!
levothyroxine ratio IV to PO?
1: 2
typical dose for armour thyroid?
60-120mg daily
usual t3 dose
25-75 mcg
liotrix
t3 and t 4
how should you separate meds that interact w/ levothryoxine?
take the other medicines 2 hours before or 4 hours after the levothyroxine
meds that interact w/ levo
calcium, mag, aluminum, iron sucralfate orlistat SPS cholestyramine --Beta blovkers, estrogen and hepatic inducers
counseling for levothyroxine
- for energy and metabolism
- take on empty stomach in the 30 minuts before BF
- it can take up to 1 or two months for the full effect of the medicine to take effect
- side effects of the medication
symptoms of hyperthyroidism?
sudden wight loss, sweating , fast HR, nervous, irritable, diarrhea, insomnia
most common cause of hyperthyroidism?
grave’s disease: immune system stimulates the thyroid gland to produce too much T4
most common medications that can cause hyperthyroidism?
iodide
amiodarone
interferons
what is the DOC for Grave’s disease?
RAI-131 : radicactive iodine
what can you use only for symptomatic treatment of hyperthyroidism?
beta blockers
two treatment medications for hyperthyroidism? med names?
PTU: propylthiouracil
Methimazole
Propyl-thyracil
PTU
Tapazole
methimazole
typicl dose of PTU
50mg TID or higher (higher doses until euthyroid, then dose reduction)
BBW PTU
can cause liver damage and acute liver failure
typical dose for methimazole
5-15 mg daily (maintenance dose) : initial doses are higher
two main side effects of PTU and methimzole
GI upset and hepatitis , agrunolocytosis (rare)
how to toake both PTU and methimazole?
w/ food to decrease GI upset
which put or methimazole is safe for pregnancy ?
methimzole, PTU is pregnancy category D. PTU ok for women trying to conceive or if they are still in the first trimester but should switch to methimazole in 2nd or 3rd trimester
what is the DOC for thyroid storm?
PTU
two iodide solutions for hyperthyroidism?
Lugol’s solution ( potassium iodide and iodine solution)
Saturated solution of potassium iodide (SSKI)
how should you take your iodide solutions?
w/ food to reduce GI upset
can you use iodide solutions in pregnancy?
no = because category D. Nor in breastfeeding
typical dose for the iodide solutions in hyperthyroidism?
4-8 drops po Q8h
what are symptoms of thyroid storm?
fever > 103 F HR > 140 inc RR profuse sweating agitation psychosis coma
Treatment for thyroid storm
PTU 900-1200 po daily divided q 4-6 hours (30 min before iodide) PLUS SSKI or lugos PLUS Propranolol PLUS dexamethasone Supportive care
dose thyroid storpe SSKI and Lugols
sski 3-5 drops q 8h
luglos 5-10 dropps po q 8h
