Thyroid hormone and antithyroid drugs

Thyroid hormones include thyroxin (T4) and triiodothyronine (T3), which are necessary for the normal growth and metabolism of the body. Insufficient or excessive secretion can cause diseases. Insufficient can affect physical and mental development, causing dysplasia (cretinism) and mucinous edema; overdose can cause hyperthyroidism. Clinically, it is mainly used as an alternative supplementary therapy for thyroid function. Indications include dysplasia, myxedema, and simple goiter. Excessive symptoms can cause hyperthyroidism. Older people and heart disease patients can induce angina pectoris and myocardial infarction. They need to stop taking drugs and use beta blockers to fight drugs. Antithyroid drugs are mainly used for the treatment of hyperthyroidism. Clinical applications include thioureas, iodides, radioactive iodine and beta blockers. Thiourea thioureas can be divided into two categories: 1 thiouracil: methylthiouracil, propylthiouracil; 2 imidazoles: methimazole (thiazazole, thiamazole), card Bimatoxa (carbamazole). Pharmacological action 1. Inhibition of thyroid hormone synthesis The basic role of thiourea is to inhibit thyroid peroxidase, prevent iodine iodine and iodine tyrosine coupling, thereby inhibiting thyroid hormone biosynthesis. There is no antagonistic effect on the synthesized thyroid hormone, and it is necessary to consume the hormone synthesized in the body to produce a therapeutic effect. Therefore, this class of drugs has a slow onset of action. The symptoms of hyperthyroidism begin to decrease after 2 to 3 weeks of treatment, and the basal metabolic rate returns to normal within 1 to 3 months. 2. Inhibition of T4 conversion of propylthiouracil can inhibit the transformation of T4 into T3 in peripheral tissues, and rapidly control the T3 level with strong biological activity in blood, and the curative effect is rapid. 3. Immunosuppressive action Thiourea can inhibit the production of immunoglobulin, and reduce the thyroid stimulating immunoglobulin in the blood. In addition to the control symptoms, there is a certain therapeutic effect on hyperthyroidism. Iodine and iodide iodine are essential raw materials for the synthesis of thyroid hormone. Different doses of iodine may have different effects on thyroid function. 1. Small doses of iodine can treat simple goiter caused by iodine deficiency. 2. Large doses of iodine can produce anti-thyroid effects, mainly inhibit the release of thyroid hormones, and also inhibit the synthesis of thyroid hormones. Its anti-thyroid effect is strong and fast, the drug takes effect in 1-2 days, and the maximum effect is achieved in 10-15 days. If you continue to take the drug, you will lose the anti-thyroid effect, and the symptoms of hyperthyroidism can recur. Clinically used for: 1 preparation for hyperthyroidism: generally, compound iodine solution is given two weeks before surgery to degenerate thyroid tissue, reduce blood vessels, reduce glandular toughness, facilitate surgery and reduce bleeding; 2 thyroid crisis treatment. The sputum receptor blocker beta-receptor blocker propranolol can rapidly counteract the symptoms of increased sympathetic activity in patients with hyperthyroidism and inhibit the conversion of peripheral T4 to T3. It is a valuable adjuvant treatment for the treatment of hyperthyroidism and thyroid crisis.