[5][6] Besides perchlorates, other examples of iodide uptake inhibitors include pertechnetates, thiocyanates, nitrates.
Since even low levels of ionizing radiation are highly mutagenic and can cause cancer,[16] less toxic iodine isotopes such as iodine-123[17] are more commonly used in nuclear imaging, while iodine-131 is used for its cytolytic (cell-destroying) effects in hyperthyroidism and thyroid tumors.
[18] The most dangerous side effect is agranulocytosis (1/250, more in PTU); this is an idiosyncratic reaction which generally resolves on cessation of drug.
[19] Other side effects include granulocytopenia (dose dependent, which improves on cessation of the drug) and aplastic anemia, and in case of propylthiouracil, severe, fulminant liver failure.
[22] In Graves' disease, treatment with antithyroid medications must be given for six months to two years, in order to be effective.
Side effects of the antithyroid medications include a potentially fatal reduction in the level of white blood cells.
A randomized control trial testing single dose treatment for Graves' found methimazole achieved euthyroidism (normal thyroid function that occurs within normal serum levels of TSH and T4[23]) more effectively after 12 weeks than did propylthiouracil (77.1% on methimazole 15 mg vs 19.4% in the propylthiouracil 150 mg groups).
These two markers are an elevated level of thyroid stimulating hormone receptor antibodies (TSHR-Ab) and smoking.
[25] Competitive antagonists of thyroid stimulating hormone receptors are currently being investigated as a possible treatment for Grave's disease.