Treatment of Thyroid Disease Flashcards
Hypothyroidism
Causes: hashimoto’s thyroiditis, surgery, RAI
- failure of thyroid gland to secrete adequate amts of thyroid hormone
- placid appearance, pale, depressed, fatigue, hypothermia, dry skin, bradycardia
Hyperthyroidism
Graves, toxic nodules, thyroiditis
tachycardia, tremor, thyroid enlargement, increase deep tendon reflex
proximal muscle weakness
dermopathy- thickened skin
ophthalmopathy
Hashimoto’s
Chronic autoimmune thyroiditis
- hypothyroidism
- ab to thyroid peroxidase and thyroglobulin
- suppression of free T3 (more potent) and T4
- elevation of TSH
primary hypothyroidism
decreased free T4 and elevated TSH
secondary hypothyroidism
secondary to hypothalamic or pituitary conditions
-decreased free t4, normal or decreased TSH
Subclinical hypothyroidism
characterized by absence of symptoms, normal free t4 and elevated tsh
levothyroxine
LT4 -needs to be taken on empty stomach -one hour away from food -initial therapy for individuals w/ no functioning thyroid or severe secondary hypothyroidism half life 7 days
-beware of advanced age and heart disease because polypharmacy may cause calcium and iron binding
Triiodothyronine/ liothyronine
T3
- most acive form
- not commonly prescribed drug due to peripheral metabolism
what increases thyroid binding globulin
estrogen, tamoxifen, methadone
What decreases thyroid binding globulin
androgen
glucocorticoids
What displaces thyroid hormone from thyroid binding globulin
salicylates and furosemide
what decreases absorption of thyroid hormone or t4
cholestyramine, colestipol, ppi, raloxifene, iron, calcium
what decreases in absorption of thyroid hormone or T4 non prescribed meds
bran, soy, coffee
Oral estrogen does what to thyroid
raises circulating levels of thyroxine binding globulin, increasing bound fraction and decreasing free fraction of t4
- may increase t4 dosage requirements
- increase by 25% for pts who are pregnant
graves disease
autoimmune disorder characterized by IgG ab to thyroid stimulating hormone receptors on thyroid cells
-enlarged thyroid, homogenous, thyroid bruit
diagnostics for graves disease
decreased tsh
increased t4/t3
increased RAIU
presence of thyroid stimulating antibodies
graves disease tx
beta blockers, ccb, radioactive iodine
thioamides- inhibit thyroid hormone synthesis
thyroidectomy
Thioamides
Propylthiouracil shorter half life
Methimazole longer half life
Block iodination process for tyrosyl groups and coupling of iodotyrosines to form
-may lead to rash and urticaria
may cause significant bone marrow depression, agranulocytosis,
toxic nodular goiter
more common in elderly than graves
-hyperfunctioning thyroid nodule
-enlarged, nodular thyroid
ophthalmopathy and dermopathy usually absent
diagnostics for toxic nodular goiter
dec TSH, increased free T4/3
RAIU and scintiscan will have hot nodule
-TSI absent
tx for toxic nodular goiter
radioactive iodine ablation
-thiomides (inh thyroid hormone synthesis)
surgery as last resort
thyroiditis
inflammation of thyroid gland may result in release excessive release of thyroid hormone, resulting in thyrotoxicosis
-decreased RAIU study
decreased TSH, inc free T4/t3
inc ESR
tx for thyroiditis
beta blockers, aspirin, nsaids, steroids
NO anti-thyroid meds
iodides
inhibit organification and hormone release
reduce size and vascularity of gland
beta blockers
propranolol
inhibit b adrenoreceptors
inhibit T4 to T3 conversion
