Thyroid And Antithyroid Drugs Flashcards
Euthyroid
Normal thyroid functions
Goiter
Enlargement of the thyroid gland causing a swelling in the front part of the neck, usually caused by hyperthyroidism
Graves’ disease
Autoimmune disorder leading to the over activity of the thyroid gland
Hashimoto thyroiditis
Autoimmune disease attacking the thyroid typically resulting in hypothyroid function
Hyperthyroidism
Overactive thyroid function
Hypothyroidism
Under active thyroid function
Thyrotoxicosis
Severe hyperthyroidism characterized by high fever, extreme tachycardia, and altered mental status (aka thyroid storm)
What happens in the case of uncorrectable hyperthyroidism
Radioactive iodine is swallowed to destroy the thyroid, so that it stops overproducing hormones, but then they will have to take thyroid supplements, or thyroid is surgically removed
Hypothyroidism signs
Decrease metabolism, anorexia, weight gain, low body temperature, bradycardia, moderate hypotension, lethargy, sleepiness, pale cool and dry skin, puffy face, coarse hair, thick and hard nails, may be unable to conceive, low sperm count
Hyperthyroidism signs
Increased metabolism, increased appetite, intolerance to heat, elevated body temperature, weight loss, tachycardia, moderate hypertension, nervousness, anxiety, insomnia, tremors, flushed and warm and moist skin, thinning hair, goiter,
Thyroid hormones MOA
Increase the metabolic rate of tissues, and result in increased heart and respiratory rate, body temperature, cardiac output, oxygen consumption, and the metabolism of fats, proteins, and carbs
Thyroid hormones uses
Treat,ent or prevention of hypothyroidism caused by subacute or chronic thyroiditis (Hashimoto disease or viral thyroiditis), hormone supplement after hyperthyroidism treatment, euthyroid goiter, thyroid nodules and multinodular goiter, some types of depression, thyroid cancer
Levothryroxine use
Drug of choice for hypothyroidism
Thyroid hormone reactions
Signs of hyperthyroidism
Thyroid hormones contraindications
Uncorrected adrenal cortical insufficiency, thyrotoxicosis, shouldn’t be used to treat obesity or infertility, shouldn’t be used after a recent myocardial infarction
Thyroid hormones precautions
Cardiac disease, lactation
Thyroid hormones pregnancy cat
A
Thyroid hormone interactions
Decreased effectiveness of digoxin and beta blockers, oral antidiabetics and insulin increase risk of hyperglycemia, oral anticoagulants prolong bleeding, SSRIs decrease thyroid effectiveness, other antidepressants increase thyroid effectiveness, and decongestants increase side effects of thyroid
Antithyroid Drugs MOA
Inhibit the manufacture of the thyroid hormones, don’t affect existing hormones, so it may be 3-4 weeks before results are seen
Thyroidectomy
When thyroid is removed, and antithyroid drugs are given previous to this surgery to return patient to a euthyroid state
Methimazole use
Medical management of hyperthyroidism
Propylthiouracil use
Medical management of hyperthyroidism
Radioactive iodine use
Treatment of hyperthyroidism and cancer of the thyroid
Antithyroid side effects
Hay fever, sore throat, rash, fever, headache, vomiting, paresthesias, severe reactions include arangulocytosis, exfoliative dermatitis, granulocytopenia, hypoprothromb-inemia, drug induced hepatitis
Methimazole contraindications
Lactation
Propylthiouracil contraindications
Lactation
Radioactive iodine contraindications
Pregnancy (cat X) and lactation
Methimazole precautions
Pregnancy (cat D)
Propylthiouracil precautions
Pregnancy (cat D), if an antithyroid Drug needs to be taken during pregnancy, choose this
Antithyroid interactions
Oral anticoagulants increase chance of bleeding
Thyroid drugs elderly considerations
Elderly are at increased risk of cardiovascular side effects, so reduce initial dosage, and any increases should be made in smaller increments
Thyroid hormones ex
Levothyroxine, liothyronine, liotrix
Antithyroid preparations ex
Methimazole, propylthiouracil
