Potassium iodide

General information

Potassium iodide is also called iodine potassium or potassium iodatum and is mainly used to treat and prevent iodine deficiency. It is also used to prevent goitre caused by iodine deficiency (thyroid enlargement).

Mode of action

Potassium iodide is an elementary trace element, but in higher doses it acts like a thyrostatic agent. The iodide is absorbed and stored by the thyroid gland so that it can then be used to produce thyroid hormones. If there is too little iodide in the body, the thyroid gland cannot produce sufficient thyroid hormones, so that an enlargement of the thyroid gland often occurs as a reaction (goiter).

An underfunctioning of the thyroid gland due to iodine deficiency can be prevented by external supply of iodine (iodine-containing foods, iodized table salt, iodine in tablet form). If the body produces too many thyroid hormones, this is known as hyperthyroidism. If potassium iodide is taken in very high doses of more than 5 milligrams per day, the release of thyroid hormones is prevented. However, this form of application is no longer in common use today.

Side effects

Side effects are very rare when taking potassium iodide, but hypersensitivity to the active substance is possible. This hypersensitivity may manifest itself as fever, burning eyes, rash, diarrhea and headaches.

Fields of application

Potassium iodide is mainly administered to treat or prevent iodine deficiency or thyroid enlargement (goiter) caused by iodine deficiency. In large concentrations, potassium iodide is used to reduce the size of an enlarged thyroid gland before surgery and to reduce the blood supply to the thyroid gland. In the past, potassium iodide was also known to be used to treat hyperthyroidism, but this use of potassium iodide is now obsolete and other thyrostatic agents such as thiamazole are used instead. The intake of potassium iodide can prevent the absorption of radioactive iodine into the organism, so it is often used as a preventive measure after an accident in a nuclear power plant.