Q: Glucocorticoids are used in thyroid storm for all of the following actions except? 

A) Reduce T4-to-T3 conversion
B) Promote vasomotor stability
C) Treat an associated relative adrenal insufficiency (if present)
D) Block new hormone synthesis


Answer: D

Thyroid storm requires multi-dimensional approach to manage different steps of thyroid synthesis, secretion, action and recirculation, like beta blocker controls the symptoms induced by increased adrenergic tone, a thionamide blocks the new hormone synthesis, an iodine solution blocks the release of thyroid hormone and an iodinated radiocontrast agent inhibits the peripheral conversion of T4 to T3. Some clinicians add bile acid sequestrants to decrease enterohepatic recycling of thyroid hormones.

Glucocorticoids reduces T4-to-T3 conversion, promote vasomotor stability, and treat an associated relative adrenal insufficiency, if present. It has no role in blocking new hormone synthesis.


Reference:

Ross DS, Burch HB, Cooper DS, et al. 2016 American Thyroid Association Guidelines for Diagnosis and Management of Hyperthyroidism and Other Causes of Thyrotoxicosis. Thyroid 2016; 26:1343.