The Sound of Evolution
Carbimazole
Mechanism of action:
Carbimazole is a thioimidazole derivative and a prodrug of methimazole. In thyroid follicular cells, thyroid peroxidase (TPO) oxidizes iodide (I-) into active iodine, possibly I+ or hypoiodous acid, and allows active iodine to bind to tyrosine residues on thyroglobulin, forming MIT (monoiodotyrosine) and DIT (diiodotyrosine). These are then coupled to form T3 (MIT + DIT) and T4 (DIT + DIT). Because carbimazole inhibits TPO activity, it blocks the production of T3 and T4.
Reference(s):
1. Chen X et al. (2002). TTD: Therapeutic Target Database. Nucleic Acids Res.
2. Guilhem I et al. (2006). Differential evolution of thyroid peroxidase and thyrotropin receptor antibodies in Graves' disease: thyroid peroxidase antibody activity reverts to pretreatment level after carbimazole withdrawal. Thyroid.