Editing Hyperthyroidism (section)

===Antithyroid drugs===
Thyrostatics ([[Antithyroid agent|antithyroid drugs]]) are drugs that inhibit the production of thyroid hormones, such as [[carbimazole]] (used in the UK) and [[methimazole]] (used in the US, Germany and Russia), and [[propylthiouracil]]. Thyrostatics are believed to work by inhibiting the [[iodination]] of [[thyroglobulin]] by [[thyroperoxidase]] and, thus, the formation of tetraiodothyronine (T<sub>4</sub>). Propylthiouracil also works outside the thyroid gland, preventing the conversion of (mostly inactive) T<sub>4</sub> to the active form T<sub>3</sub>. Because thyroid tissue usually contains a substantial reserve of thyroid hormone, thyrostatics can take weeks to become effective and the dose often needs to be carefully titrated over a period of months, with regular doctor visits and blood tests to monitor results.<ref name="Thyrotoxicosis and Hyperthyroidism"/>