Definition
A thiourea antithyroid agent. Propythiouracil inhibits the synthesis of thyroxine and inhibits the peripheral conversion of throxine to tri-iodothyronine. It is used in the treatment of hyperthyroidism. (From Martindale, The Extra Pharmacopeoia, 30th ed, p534)
Description
Propylthiouracil is only found in individuals that have used or taken this drug. It is a thiourea antithyroid agent. Propythiouracil inhibits the synthesis of thyroxine and inhibits the peripheral conversion of throxine to tri-iodothyronine. It is used in the treatment of hyperthyroidism. Propylthiouracil 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. Therefore propylthiouracil effectively inhibits the production of new thyroid hormones.
Top Gene Interactions
Related Pathways
General Information
- Metabolism: Route of Elimination: Propylthiouracil is readily absorbed and is extensively metabolized. Approximately 35% of the drug is excreted in the urine, in intact and conjugated forms, within 24 hours. Half Life: 2 hours
- Uses/Sources: Used to manage hyperthyroidism which is due to an overactive thyroid gland (Grave's disease).
- Route of Exposure: Well absorbed following oral administration.
Toxicity
- Carcinogenicity: 2B, possibly carcinogenic to humans. (L135)
- Toxicity: Oral, rat: LD<sub>50</sub> = 1250 mg/kg.
Mechanism of Action
Target Name | Mechanism of Action | References |
---|---|---|
Estrogen receptor Thyroid peroxidase |
2656250 23611293 11241400 11752352 12755690 17379648 10365684 |