Product Information
Registration Status: ActiveSIN09589P
THYROZOL TABLET 5mg is approved to be sold in Singapore with effective from 1997-12-22. It is marketed by MERCK PTE LTD, with the registration number of SIN09589P.
This product contains Thiamazole 5mg in the form of TABLET, FILM-COATED. It is approved for ORAL use.
This product is manufactured by MERCK KGAA in GERMANY, andMerck KGaA & Co. Werk Spittal (Primary and Secondary packager) in AUSTRIA.
It is a Prescription Only Medicine that can only be obtained from a doctor or a dentist, or a pharmacist with a prescription from a Singapore-registered doctor or dentist.
Product Reference
Important Note: For generic product, the SPC/PIL provided may not be brand specific.
{{/items}} {{^items}}Description
A thioureylene antithyroid agent that inhibits the formation of thyroid hormones by interfering with the incorporation of iodine into tyrosyl residues of thyroglobulin. This is done by interfering with the oxidation of iodide ion and iodotyrosyl groups through inhibition of the peroxidase enzyme. [PubChem]
Indication
For the treatment of hyperthyroidism, goiter, Graves disease and psoriasis.
Mechanism of Action
Methimazole binds to thyroid peroxidase and thereby inhibits the conversion of iodide to iodine. Thyroid peroxidase normally converts iodide to iodine (via hydrogen peroxide as a cofactor) and also catalyzes the incorporation of the resulting iodide molecule onto both the 3 and/or 5 positions of the phenol rings of tyrosines found in thyroglobulin. Thyroglobulin is degraded to produce thyroxine (T4) and tri-iodothyronine (T3), which are the main hormones produced by the thyroid gland. So methimazole effectively inhibits the production of new thyroid hormones.
Pharmacokinetics
- Absorption
- Rapid with an oral bioavailability of 93%.
- Distribution
- Metabolism
- Primarily hepatic. Metabolized rapidly, requiring frequent administration.
- Elimination
Toxicity
Oral LD50 in rats is 2250 mg/kg. Symptoms of overdose include nausea, vomiting, epigastric distress, headache, fever, joint pain, pruritus, and edema. Aplastic anemia (pancy-topenia) or agranulocytosis may be manifested in hours to days. Less frequent events are hepatitis, nephrotic syndrome, exfoliative dermatitis, neuropathies, and CNS stimulation or depression.
Active Ingredient/Synonyms
1-METHYL-1,3-dihydro-2H-imidazole-2-thione | 1-Methylimidazole-2(3H)-thione | Danantizol | Favistan | Mercazolyl | Methimazole | Strumazol | Thacapzol | Thiamazol | Thiamazole | Thiamazolum | Tiamazol | USAF el-30 | Methimazole |
Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.