Inhibits the production of thyroid hormone by blocking the activity of an enzyme called thyroperoxidase, which is involved in the synthesis of thyroid hormones.
Reduces the conversion of the thyroid hormone thyroxine (T4) to its active form, triiodothyronine (T3), by inhibiting another enzyme called 5′-deiodinase.
May also have some immunosuppressive effects.
Spectrum:
PTU is mainly used in the treatment of hyperthyroidism, including Graves’ disease, toxic multinodular goiter, and toxic adenoma.
It can also be used in the treatment of thyroid storm, a life-threatening complication of hyperthyroidism.
PTU may be used in pregnant women with hyperthyroidism, as it is considered safer than methimazole, another medication used for hyperthyroidism, during pregnancy.