Antithyroid agent

Antithyroid drugs are drugs that inhibit thyroid function and be used against hyperthyroidism.

We distinguish substances that inhibit the synthesis of thyroid hormones ( Iodisationshemmstoffe, Thiamide, about Carbimazole / thiamazole (active form), propylthiouracil ), and substances in the thyroid cell inhibit iodide transport ( Iodinationshemmstoffe, such as perchlorate ). In addition, high doses of iodine have even a limited period of time an inhibiting effect on the thyroid (see Wolff Chaikoff effect).

Indications

Antithyroid drugs are used in various forms of hyperthyroidism are used:

  • Graves' disease: autoimmune disease, prone to spontaneous remissions but also recurrences. Treatment with antithyroid is over 12 performed 18 months and is intended to bridge the time until an eventual remission. The beginning of the therapy is performed with a high initial dose is reduced by setting a euthyroid metabolic state ( after about 3-6 weeks) to a maintenance dose. The substitution of thyroxine (T4 ) may facilitate metabolic control. The recurrence rate is estimated at up to 50 %, in the case of recurrence further treatment by means of radioiodine or subtotal / total thyroidectomy
  • Functional thyroid autonomy: areas with no demand-oriented, autonomous secretion of thyroid hormones. With spontaneous remissions is - in contrast to Graves' disease - not to be expected that antithyroid therapy aims at setting a euthyroid metabolic state in preparation for radioiodine therapy / surgery.
  • Jodinduzierte hyperthyroidism: at existing, latent autonomy, a single dose high-dose iodine lead (in the context of a Konstrastmittelgabe X-ray examinations, for example ) the clinical picture of hyperthyroidism. The treatment is lengthy and sometimes is done with a combination of antithyroid and perchlorate. Prophylaxis against such studies is possible with these substances.

Adverse effects of antithyroid therapy

  • Blood dyscrasias (agranulocytosis, leukopenia )
  • Allergic reactions
  • Hypothyroidism
  • Struma
  • Gastrointestinal complaints

Growth promoters

Antithyroid drugs were formerly used in animal production as growth promoters. Since 1981, this use is prohibited in the states of the EU.

Sources and References

  • Kay Brune: Pharmacotherapy: Clinical pharmacology. Springer, March 2010, ISBN 978-3-642-10540-1, pp. 365-9 (accessed on 25 February 2012).
Cure Medical Subject Headings
774468
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