Some Basics Regarding The Use Of Lugols Iodine Solution

By Elaine Guthrie


Iodine is available in many different forms. Since it was first prepared in1829 by a French physician, Lugols iodine solution, continues to play a major role in scientific research and everyday use. The solution is prepared by dissolving elemental iodine and the compound potassium iodide in water. It is diluted to various concentrations depending on the intended use. It is also known as iodine potassium iodide Markodine or Strong solution.

For topical use such as in the case of minor wounds on the skin there are several formulations available. The main types used include ointment, gel or tincture. Commonly, these formulations are mixed with another ingredient known as povidone which serves to increase the effectiveness. The tincture is also said to be effective in emergency disinfection of water. The mechanism of action is not clear in this case.

Lugols has a characteristic reaction in the presence of starch which is widely available in many organic compounds. When it interacts with the polysaccharides that make up starch molecules there is a blue black colour change and this is considered a positive reaction. For this reason, the solution is used in a number of biochemical experiments. The same reaction is seen when testing for a condition known as amyloidosis in living cells.

In medical practice there is extensive use of the solution in management of cancer patients. It is particularly important in screening for cervical cancer. Staining of the cervix and upper vaginal wall is done under examination done using an instrument known as a colposcope. The normal tissues stain deeply with the brown colour while the suspicious areas remain paler. Biopsy specimens are taken from the paler areas.

The solution has been used in a number of selected patients suffering from Graves disease. The disease is a severe form of hyperthyroidism. Administering the solution during thyroidectomy (removal of thyroid gland), helps in reducing blood loss. This benefit is, however, not seen in patients whose thyroid hormonal levels are within the normal ranges or in those that are on medication.

In the early years of its discovery, the solution was an important treatment of gout. With scientific advancement over the years, it has fallen out of favour. The same fate has befallen it for the treatment of hyperthyroidism in which case it had been the first line drug for a long time. The main side effect associated with it was inhibition of thyroid hormone synthesis (also known as the Wolff Chaikoff effect).

In the marine and aquarium industry, the compound is vital for macroalgae growth and for the survival of coral reef inhabitants. This effect is believed to be the result of a reduction in the number of unwanted bacteria and parasites within the same habitat. The other major benefit is the expansion of polyps and prevention of coral bleaching in instances where the light intensity is abnormally high.

In excessive levels Lugols may be harmful to the body. Undiluted solutions are both irritating and destructive to the mucosa particularly that of the stomach and the esophagus. This has been seen in some cases of endoscopic examination. Generally, however, it is considered to have low toxicity.




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