Antithyroid Drug ATD


aliases:

  • ATD
  • Antithyroid Drugs

Pharmacological Effects

The synthesis of thyroid hormones requires the participation of [[thyroid peroxidase TPO]]. By inhibiting TPO, thyroid hormone synthesis can be suppressed. See also [[thyroid hormones]].

Inhibits the organification of iodine and the coupling of thyroid tyrosine, reducing the synthesis of thyroid hormones.
No inhibitory effect on hormones already synthesized.

Classification

Thioamides Imidazoles
Examples [[Propylthiouracil PTU]], [[Methimazole]] [[Methimazole MMI]], [[Carbimazole]]

[[Thyouracil]]

Clinical Applications

Basic treatment of hyperthyroidism—[[Methimazole MMI]] preferred; for thyroid storm and hyperthyroidism during pregnancy, [[Propylthiouracil PTU]] is used (lower teratogenicity).

Surgery and 131I therapy are complementary.

Adverse Reactions

All can cross the placenta.

Granulocytopenia, drug rash, toxic liver disease.
A complete blood count (especially white blood cells) must be performed before starting treatment.

Discontinuation Indications