What is Wolff-Chaikoff syndrome?

Hypothyroidism can be caused by iodine deficiency (see Chapter 88) or iodine excess. Inorganic iodide in excess of daily doses of 500 to 1000 mcg inhibits organification of iodide, known as the Wolff-Chaikoff effect.

How does the Wolff-Chaikoff effect work?

Wolff-Chaikoff effect is an autoregulatory phenomenon, whereby a large amount of ingested iodine acutely inhibits thyroid hormone synthesis within the follicular cells, irrespective of the serum level of thyroid-stimulating hormone (TSH) 1.

Why iodides are used both for treatment hypothyroidism and hyperthyroidism?

Iodide is known to control thyroid function. Its main effects are to decrease the response of the thyroid to thyrotropin (TSH); to acutely inhibit its own oxidation; to reduce its trapping after a delay; and, at high concentrations, to inhibit thyroid hormone secretion12).

How do Goitrogens affect the thyroid?

Goitrogens can reduce the thyroid’s ability to produce the hormones your body needs to function normally. They are more likely to negatively impact people who already have poor thyroid function.

What is Jod Basedow effect?

The Jod-Basedow effect (also Jod-Basedow syndrome and Jod-Basedow phenomenon) is hyperthyroidism following administration of iodine or iodide, either as a dietary supplement, iodinated contrast medical imaging, or as a medication (mainly Amiodarone).

How do iodides work in hyperthyroidism?

Thyroid storm because iodine blocks the release of T4 and T3 from the gland within hours. As adjunctive therapy for Graves disease, used in combined treatment with antithyroid drugs and KI improves the short-term control of Graves hyperthyroidism.

How long does Wolff Chaikoff effect last?

The Wolff–Chaikoff effect lasts several days (around 10 days), after which it is followed by an “escape phenomenon,” which is described by resumption of normal organification of iodine and normal thyroid peroxidase function.

What is Jod Basedow phenomenon?

Jod-Basedow phenomenon occurs due to either overactivation of the entire thyroid gland or, more commonly, autonomous nodules within the gland after iodine repletion without adequate feedback control from the pituitary gland. This escape from the protective Wolff-Chaikoff effect is called the Jod-Basedow phenomenon.

Are goitrogens good for hypothyroidism?

Goitrogens. Goitrogens are compounds that may affect thyroid function if a person consumes large amounts. However, in regular amounts, vegetables that contain goitrogens, such as broccoli and bok choy, are beneficial for overall health and do not interfere with thyroid function.

Can goitrogens cause hypothyroidism?

Soy. Soybeans contain two goitrogens: genistein and daidzein. These are often referred to as soy flavonoids or soy isoflavones, which we are usually told are good for us, yet it has long been known that these compounds can cause hypothyroidism and goiter.

What does methimazole do to the body?

Methimazole can lower blood cells that help your body fight infections and help your blood to clot. This can make it easier for you to bleed from an injury or get sick from being around others who are ill. Your blood may need to be tested often.

What type of drug is Carbimazole?

Carbimazole and propylthiouracil belong to a group (class) of medicines called thionamides. Thionamides have similar actions on the thyroid gland.

What is the Wolff-Chaikoff effect?

Wolff-Chaikoff Effect: Iodine induced hypo thyroidism. Can occur in normal or hyperthyroid state. Can be used as treatment against hyperthyroidism (i.e thyroid storm); Excess iodide transiently inhibits thyroid iodide organification.

What is Jod-Basedow phenomenon?

Jod-Basedow Phenomenon: Iodine induced hyper thyroidism. In individuals with iodine deficient hypothyroidism, thyroid hormone synthesis becomes excessive as a result of increased iodine exposure. NOTE: this does not occur in euthyroid individuals! Woeber, KA. Iodine and thyroid disease. Med Clin North Am. 1991 Jan;75 (1):169-78.

What is Jod-Basedow effect in goiter?

The Jod-Basedow effect is hyperthyroidism following administration of iodine or iodide either as a dietary supplement or as contrast medium. This phenomenon is an iodine-induced hyperthyroidism, typically presenting in a patient with endemic goiter who then relocates to an iodine-abundant geographical area.

What is Jajod-Basedow syndrome?

Jod-Basedow syndrome, also known as iodine-induced hyperthyroidism, is a rare cause of thyrotoxicosis seen typically after the administration of exogenous iodine. This syndrome is often associated with iodinated contrast media used in conjunction with computed tomography (CT) scans, angiography, and various other imaging studies.