Iodine is a chemical element and has the element symbol I with the atomic number 53. Iodine is in the 7th main group of the periodic table and therefore belongs to the halogens (salt formers). The word iodine comes from ancient Greek and stands for violet, violet. Iodine is a solid that looks like a crystal and has a metallic sheen. Even at room temperature this solid emits violet vapors.

Iodine in the body

Iodine is very important for thyroid metabolism.

Humans need iodine as an essential building block for the synthesis of Thyroid hormones. So that the body has enough iodine available, the daily intake of iodine in food should not fall below 200 micrograms. Iodine tablets can be prescribed in the event of iodine deficiency. Since the thyroid is responsible for the production of thyroid hormones, the iodine ingested with food is almost completely stored in the thyroid.

Medical application

Iodine is applied and used in different places in medicine. Especially as Disinfectants and in more radioactive Iodine is used in medicine.

Iodine as a disinfectant

Iodine has been used as a disinfectant for cleaning wounds for a very long time. Disinfecting means the opposite of infecting. Microorganisms that cause infection are thus rendered harmless by disinfection. Microorganisms are bacteria, viruses and fungi. The pathogens are damaged by the disinfectant, so that they lose their ability to infect humans. The disinfectant damages the shell of the microorganisms or spores. In addition to chemical substances, radiation or heat can also have a disinfectant effect. Since bacteria etc. were discovered as pathogens, people have also looked for substances to kill these pathogens. The first disinfectants already contained iodine.

Today's disinfectants containing iodine (for example iodine tincture or iodoform) contain iodine in elemental form. They are used as an antifungal and antiseptic. The antibacterial effect of iodine is presumably based on the fact that iodine splits off oxygen from water. This oxygen is then very reactive and forms a connection with the cell wall of the pathogen, thereby damaging it and making it leaky. Today iodine is widely used as a disinfectant. It is unsuitable for surfaces and objects. The areas of application for disinfectants containing iodine are the skin and mucous membranes. Disinfectants containing iodine are used in particular to clean the skin before operations. The disinfectant is applied generously to the operating area with swabs before the operation. You start inside and go out in circles. The entire operating area is generously moistened several times. Iodine works against bacteria (bactericidal) and against fungi (fungicide). Furthermore, it is (less) effective against spores and viruses (virucidal). Iodine in the disinfectant has two side effects, it burns when used and it leaves a stubborn yellow color.

If you are injured, you should disinfect the wound. This is especially necessary in the case of large-scale abrasions and wounds that are contaminated. To do this, the wound should be cleaned with the iodine-containing disinfectant for at least thirty seconds. At the same time, you should also remove coarse dirt. Then the wound or the disinfectant is allowed to dry and the wound is connected with a sterile bandage or the like. It is important that the wound is dry when it is bandaged. Furthermore, iodine-containing disinfectants can be used in the mouth and throat. For example, if you have tonsillitis, you can use an iodine solution to gargle. The iodine solution should only be used in diluted form; you should ask a specialist (pharmacist, doctor) about this. In addition, you shouldn't gargle too long, as the oral mucosa can be irritated. In addition, it must be noted that the diluted iodine solution must not be swallowed. Disinfectants containing iodine, such as tincture of iodine, are now available cheaply.

Since the disinfectant also contains large amounts of iodine, an iodine allergy can occur, which can also be dangerous. For further information, we recommend our website: Iodine allergy - what to watch out for

Radioiodine therapy

There are some radioactive iodine isotopes that are used in the medical field. The most important is the radioactive iodine isotope 131 iodine. It is a beta emitter with a half-life of around eight days and is used in the Radioiodine therapy used because it is only stored in the cells of the thyroid gland in the human organism.
The radioiodine therapy is a procedure from the field of nuclear medicine, it is used to treat the Graves disease, thyroid autonomy and certain Thyroid tumors.

Radioiodine therapy has been carried out for half a century and is now considered a very safe procedure without many side effects.
Since radio iodine therapy, as the name suggests, is carried out with radioactive, i.e. radiating iodine, it is subject to certain statutory provisions.

In Germany, it can only be performed in a hospital, i.e. in an inpatient setting. The attending physician must have authorization to carry out the therapy. The radioiodine therapy must also be carried out on a nuclear medicine therapy station.

How radioiodine therapy works

The radioactive iodine is taken orally either as a tablet or in the form of a liquid, if this is not possible, the iodine can also be taken into the vein (intravenous) administer. The iodine reaches the Gastrointestinal tract in the blood and is absorbed by the thyroid gland. The thyroid then stores the radioactive iodine in the Thyroid follicles.

Radioiodine therapy is based on the fact that the thyroid is the only organ that absorbs iodine. The iodine does not accumulate anywhere else in the body. As a result, the thyroid is effectively irradiated and can be destroyed, at the same time the rest of the body is almost completely spared and there are usually few side effects from the radiation.

Applications of radioiodine therapy

Radioiodine therapy is used for diseases of the thyroid gland. The most important diseases for which radioiodine therapy can be carried out are the autonomic dysfunction of the thyroid gland (autonomous adenoma, disseminated autonomy and multifocal autonomy), Graves disease and some types of thyroid cancer (namely the tumors that take up iodine, which is a requirement for radioiodine therapy). There may be alternative drug therapies for certain diseases.
Usually the only real alternative to radioiodine therapy is surgical removal of the thyroid gland. When choosing between radioiodine therapy and thyroid surgery, various aspects must be considered. Examples are the patient's age and accompanying illnesses.

Old age and many comorbidities are more likely to speak in favor of radioiodine therapy in order to avoid the stress of an operation. However, there are a few other aspects that speak in favor of an operation. For example, hyperthyroidism caused by iodine should be treated with surgery. Important arguments for an operation are also a suspicion of a malignant one tumor or when surrounding structures are pinched by the thyroid gland.

An absolute contraindication for radioiodine therapy is an existing pregnancy (in the case of benign thyroid diseases). You should also avoid pregnancy if you have received radioiodine therapy about six months previously.

Iodine in contrast media

Contrast media are used in various imaging processes to make certain structures more visible. Such imaging methods are, for example, X-ray examinations or magnetic resonance tomography. In such examinations, contrast media are sometimes administered prior to imaging. Some of these contrast media contain iodine. Contrast agents work by enhancing or altering the signal generated by the examination and converted into images. For example, contrast media containing iodine make the vessels, which are otherwise invisible in the X-ray examination, visible if they have been injected into the vessels beforehand. In general, contrast media containing iodine are injected as water-soluble substances into the vessels or tissue or into hollow organs.

For example, the kidneys and lower urinary tract or the veins and arteries are shown with iodine-containing contrast media. Different iodine-containing contrast media usually differ in the substances to which the iodine is bound (carrier substances). The different contrast media are different in their effect and their tolerance. A possible side effect of using iodine-containing contrast media is hyperthyroidism. Before using iodine-containing contrast media, it is essential to clarify any thyroid diseases. Contrast media containing iodine are almost completely (90%) excreted via the kidneys.

Since the contrast medium contains large amounts of iodine, this can, among other things, trigger a severe allergic reaction. For further information, we recommend our website: Iodine allergy - what to watch out for