Methimazole Systematic (IUPAC) name 1-methyl-3H-imidazole-2-thione Clinical data AHFS/Drugs.com MedlinePlus Pregnancy cat. D (US) Legal status ℞-only (US) Routes Oral Pharmacokinetic data Bioavailability 93% Protein binding None Metabolism Hepatic Half-life 5-6 hours Excretion Renal Identifiers CAS number ATC code H03 PubChem DrugBank ChemSpider UNII KEGG ChEBI ChEMBL Chemical data Formula C4H6N2S Mol. mass 114.17 g/mol SMILES & Physical data Melt. point 146 °C (295 °F) Solubility in water 2.75 mg/mL (20 °C) (what is this?)
Methimazole is a drug used to treat hyperthyroidism, a condition that usually occurs when the thyroid gland is producing too much thyroid hormone. It may also be taken before thyroid surgery to lower thyroid hormone levels and minimize the effects of thyroid manipulation.
Mechanism of action
It does not inhibit the action of the sodium-dependent iodide transporter located on follicular cells' basolateral membranes. Inhibition of this step requires competitive inhibitors such as perchlorate and thiocyanate.
It is important to monitor any symptoms of fever or sore throat while taking methimazole; this could indicate the development of agranulocytosis, an uncommon but severe side effect resulting from a drop in the white blood cell count (to be specific, neutropenia, a deficiency of neutrophils). A complete blood count (CBC) with differential is performed to confirm the suspicion, in which case the drug is discontinued. Administration of recombinant human granulocyte colony-stimulating factor (rhG-CSF) may increase recovery.
Other side effects include
- skin rash
- abnormal hair loss
- upset stomach
- loss of taste
- abnormal sensations (tingling, prickling, burning, tightness, and pulling)
- joint and muscle pain
- decreased white blood cells
- decreased platelet
- Aplasia cutis congenita (prenatal exposure)
Adverse effects may occur for individuals who:
- Take anticoagulants ('blood thinners') such as warfarin (Coumadin), diabetes medications, digoxin (Lanoxin), theophylline (Theobid, Theo-Dur), and vitamins
- Have ever had any blood disease, such as decreased white blood cells (leukopenia), decreased platelets (thrombocytopenia), or aplastic anemia, or liver disease (hepatitis, jaundice)
- Are pregnant, or going to become pregnant, or are breast-feeding. An alternative anti-thyroid drug, propylthiouracil, is often substituted during pregnancy or breast-feeding. If pregnancy occurs while taking methimazole, switching to propylthiouracil may be an alternative. Early studies suggested that methimazole may harm the fetus; however, more recent studies suggest this may not be the case.
- Are going to have surgery, including dental surgery.
- ^ Nakamura H, Noh JY, Itoh K, Fukata S, Miyauchi A, Hamada N (June 2007). "Comparison of methimazole and propylthiouracil in patients with hyperthyroidism caused by Graves' disease". The Journal of clinical endocrinology and metabolism 92 (6): 2157–62. doi:10.1210/jc.2006-2135. PMID 17389704. http://jcem.endojournals.org/cgi/pmidlookup?view=long&pmid=17389704.
- ^ Crescioli C, Cosmi L, Borgogni E, et al. (October 2007). "Methimazole inhibits CXC chemokine ligand 10 secretion in human thyrocytes". J. Endocrinol. 195 (1): 145–55. doi:10.1677/JOE-07-0240. PMID 17911406. http://joe.endocrinology-journals.org/cgi/pmidlookup?view=long&pmid=17911406.
Thyroid therapy (H03) Thyroid hormones Antithyroid preparationsSodium-iodide symporter
Wikimedia Foundation. 2010.
Look at other dictionaries:
methimazole — /me thim euh zohl , thuy meuh /, n. Pharm. a white crystalline substance, C4H6N2S, that inhibits thyroxin synthesis, used in the treatment of hyperthyroidism. [METH(YL) + IM(ID)AZOLE] * * * … Universalium
methimazole — noun A thioamide drug, 1 methyl 3H imidazole 2 thione, used to treat hyperthyroidism … Wiktionary
methimazole — An antithyroid drug similar in action to propylthiouracil. * * * me·thi·ma·zole me thī mə .zōl, mə n a drug C4H6N2S used to inhibit activity of the thyroid gland * * * meth·im·a·zole (meth imґə zōl) [USP] a thyroid inhibitor, used in… … Medical dictionary
methimazole — me·thi·ma·zole … English syllables
methimazole — n.; see carbimazole … The new mediacal dictionary
methimazole — meˈthīməˌzōl, məˈ noun ( s) Etymology: methyl + imidazole : a drug C4H6N2S used to inhibit activity of the thyroid gland … Useful english dictionary
Hyperthyroidism — Classification and external resources Triiodothyronine (T3, pictured) and thyroxine (T4) are both forms of thyroid hormone. ICD 10 … Wikipedia
Carbimazole — Systematic (IUPAC) name ethyl 3 methyl 2 sulfanylidene imidazole 1 carboxylate Clinical data Trade names Neo mercazole … Wikipedia
Thioamide — (rarely, thionamide) is a functional group with the general structure R CS NR R , where R, R , and R are organic groups. They are analogous to amides except that they exhibit greater multiple bond character between the C N bond. One of the best… … Wikipedia
Liste Des Maladies Rares — Liste des maladies commençant par une lettre Mise en garde médicale Maladie rare Liste des maladies rares Commençant par un chiffre Commençant par une lettre … Wikipédia en Français