Emergency Medical Minute

Contributor: Travis Barlock MD Educational Pearls: Clinical picture: A patient comes in with altered mental status, tachycardia, fever, elevated T4, and low TSH. What’s the diagnosis?... Thyrotoxicosis secondary to Graves’ Disease. How do you treat thyrotoxicosis? First, give a beta-blocker such as propranolol. This suppresses the elevated adrenergic activity. Second, give a thionamide such as propylthiouracil (PTU) or methimazole. This decreases the synthesis of new thyroid hormone. PTU is preferred because it also blocks the conversion of T4 to T3. Third, give an iodine solution such as potassium iodide. This blocks the release of thyroid hormone through a mechanism called the Wolff-Chaikoff effect. Note, this should be given about an hour after the PTU/methimazole to ensure iodine cannot be taken up and used to synthesize more thyroid hormone in individuals with toxic adenoma or toxic multinodular goiter. Fourth, give a glucocorticoid such as hydrocortisone. This will reduce thyroid hormone convers