Thyroid drugs Flashcards
What are the symptoms of hypothyroidism?
Fatigue, cold intolerance, weight gain, nonpitting edema, decreased deep tendon reflex and dry skin.
How do you treat hypothyroidism? What is the side effect of this drug?
Levothyroxine (T4) or liothyronine sodium (T3, emergency)
Side effect:
Levothyroxine- tachycardia, heat intolerance and tremors
Liothyronine sodium- for myxedema coma, cardiotoxic (not used in heart disease)
What are the symptoms of hyperthyroidism?
Exophthalmus, intolerance to heat, sweating, weight loss, muscle weakness, fatigue but not able to sleep, tremor of hands.
How is T3 synthesized?
Combination of one DIT and one MIT molecule
How does propylthiouracil inhibit T3?
Inhibits peroxidase enzyme- no iodination or coupling.
What are the differences between propylthiouracil and methimazole?
Propylthiouracil- inhibits peroxidase enzyme and inhibits peripheral deiodination of T4 to T3. Causes liver failure safe in 1st trimester of pregnancy.
Methimazole- only inhibits peroxidase enzyme. Causes cholestatic dysfunction and safe in 2nd and 3rd trimester of pregnancy.
Why do you need to check WBC while taking methimazole?
Can cause agranulocytosis.
When do you use iodide?
Preoperative preparation of thyroid gland, thyrotoxic crisis and radioactive iodine fallout.
What is the most important side effect of I131 treatment?
Hypothyroidism
How do you diagnose thyroid storm?
Tachycardia, nausea, agitation, confusion, coma and death.
How do you treat thyroid storm?
Intravenous fluids, antipyretics Propylthiouracil B blockers Hydrocortisone Oral iodides Treat underlying illness
How do you diagnose myxedema coma?
Medical emergency with hypothermia, respiratory depression and LOC.
How do you treat myxedema coma?
Liothyronine sodium
Which B blockers are contraindicated in hyperthyroidism?
B blockers with ISA
