Skip to main content
An official website of the United States government
Government Funding Lapse
Because of a lapse in government funding, the information on this website may not be up to date, transactions submitted via the website may not be processed, and the agency may not be able to respond to inquiries until appropriations are enacted.

The NIH Clinical Center (the research hospital of NIH) is open. For more details about its operating status, please visit cc.nih.gov.

Updates regarding government operating status and resumption of normal operations can be found at opm.gov.

methimazole

A thioamide inhibitor of the enzyme thyroid peroxidase (TPO), with antithyroid activity. Upon administration, methimazole inhibits the metabolism of iodide and the iodination of tyrosine residues in the thyroid hormone precursor thyroglobulin by TPO; this prevents the synthesis of the thyroid hormones triiodothyronine (T3) and thyroxine (T4).
US brand name:Tapazole
Search NCI's Drug Dictionary