Repeated USMLE Questions Step 1- 164

A 33-year-old man presents to his physician to discuss his plans for treatment of hyperthyroidism. One of the options is potassium perchlorate.

What is the mechanism of action of potassium perchlorate as anti-thyroid?

A-Blocking of coupling of iodotyrosines

B-Blocking of peroxidase catalyzed reactions

C-Blocking of peripheral deiodination of T3 and T4

D-Competitive inhibition of iodide transport mechanism

E-Inhibition of the release of thyroid hormone from the thyroid gland


Potassium perchlorate prevents the uptake of iodine by thyroid gland by competitive inhibition of iodide transport mechanism.

The correct answer is D

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