Propylthiouracil (PTU) is a thioamide drug used to treat hyperthyroidism. It is a medicine that is used to decrease the amount of thyroid hormone produced by the thyroid gland. PTU inhibits many steps in the synthesis of thyroid hormones, including the addition of iodide to thyroglobulin by the enzyme thyroperoxidase, a necessary step in the synthesis of thyroxine, and by inhibiting the enzyme 5'-deiodinase which converts T₄ to T₃.

Notably, PTU does not inhibit the action of the sodium-dependent iodide transporter located on follicular cells' basolateral membranes. Inhibition of this step requires competitive inhibitors such as perchlorate and thiocyanate.

External links

• Propylthiouracil (patient information)

Antithyroid drugs