1. inhibits iodine uptake Thiocyanate and Perchlorate (Anion Inhibitors)

  2. inhibits both thyroid peroxidase & 5′-deiodinase Propylthiouracil (PTU)

  3. inhibits thyroid peroxidase only. Methimazole

  4. inhibit the process of proteolysis of thyroglobulin Potassium iodide

  5. inhibit peripheral conversion of T4 to T3. Glucocorticoids

Thyroid peroxidase

TPO is the enzyme responsible for oxidation and organifcation of iodide as well as coupling of monoiodotyrosine (MIT) and di-iodotyrosine (DIT).

Antibodies against thyroid peroxidase are present in more than 90% of patients with autoimmune (Hashimoto’s) thyroiditis.


Anti-thyroid Drugs

If anti-thyroid drugs are continued for 1-2 years after euthyroid state is reached, ~one-half of patient attain remission.

Preparations

  1. KI:
  2. Lugols iodine (5% iodine + 10% K iodide):
  3. Ipodate (which inhibits the conversion of T4 to T3.