| Item |
Information |
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Drug Groups
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approved |
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Description
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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. |
| Pharmacology |
Used in the treatment of hyperthyroidism or an overactive thyroid gland, methimazole inhibits the synthesis of thyroid hormones and thus is effective in the treatment of hyperthyroidism. It may also be used to ameliorate hyperthyroidism in preparation for subtotal thyroidectomy or radioactive iodine therapy. |
| 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. |
| Affected Organisms |
| • |
Humans and other mammals |
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| Biotransformation |
Primarily hepatic. Metabolized rapidly, requiring frequent administration. |
| Absorption |
Rapid with an oral bioavailability of 93%. |
| Half Life |
5-6 hours |
| Protein Binding |
None or minimal |
| Elimination |
Methimazole is excreted in the urine. |
| External Links |
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