3 hormones secreted by the thyroid gland essential for metabolism
thyroxine (T4)
tri-iodothyronine (T3)
calcitonin
functions of the thyroid gland
-regulate protein, lipid, carb metabolism
- assist with growth and development
-thermoregulation
-effective cardiovascular, neuromuscular and endocrine systems
primary deficiency in thyroid hormones
most common, abnormality in the thyroid gland itself
secondary deficiency in thyroid hormones
when the pituitary gland is dysfunctional and doesn’t secrete TSH
tertiary deficiency in thyroid hormones
when the hypothalamus doesn’t secrete thyrotropin-releasing hormone and then TSH is reduced.
congenital hypothyroidism
myxedema
goiter
enlargement of thyroid gland
-form overstimulation by elevated TSH
- TSH is elevated because theres no thyroid hormone in circulation
common symptoms of hypothyroidism
cold intolerance, unintentional weight gain, depression, dry hair, fatigue
ex of thyroid replacement drugs
levothyroxine (Synthroid, Eltroxin, Euthyrox)
thyroid replacement drugs MOA
what decreases the absorption of thyroid drugs
soybeans, walnuts, calcium, fiber
indications of thyroid drugs
contraindications of thyroid replacement drugs
MI, adrenal insufficiency, hyperthyroidism
adverse effects of thyroid replacement drugs
-cardiac dysrhythmias
-may cause (like hyperthyroidism) tachycardia, palpitations,angina, hypertension, insomnia
thyroid replacement drug interactions
enhance warfarin. reduce efficacy of digoxin and insulin, increased sensitivity to epinephrine, cholestyramine, Ca, Al bind to GI tract and reduce absorption
can you discontinue thyroid replacement drugs abruptly
NO
when should you take thyroid replacement drugs
SAME TIME EVERY DAY. AM is better for insomnia
changing thyroid replacement drug brands
dont interchange brands. different brands have different doses and destabilize treatment
hyperthyroidism causes
graves disease, multinodular disease, plummer disease (rare), thyroid storm (induced by stress or infection)
hyperthyroidism symptoms
increased metabolism
- diarrhea, flushing, increased appetite, muscle weakness, palpations, nervous
antithyroid drugs are used to treat
treat hyperthyroidism and to prevent surge of thyroid hormones after surgical treatment or during radioactive iodine treatment.
antithyroid drugs may cause…
liver and bone disease
radioactiive iodine treatment