Potassium iodide or KI is an nonradioactive iodine salt that blocks the uptake of radioactive iodine. This reduces your risk of thyroid cancer if you are at risk of exposure to radioactive iodine, which may be released into the air, water or food supply after a nuclear event. That means you could breathe it in or drink or eat something that contains that iodine.
General Caution
KI blocks radioactive iodine by flooding the thyroid with a medical form of iodine so that your body eliminates the radioactive form in the urine. This does not mean that when there is a reactor leak or nuclear disaster somewhere in the world that you should automatically start taking KI in large doses, or any dose at all, for that matter. There are certain side effects and risks associated with taking it and even contraindications in some individuals, according to the FDA.
Side Effects
KI can cause side effects, although the chances are low if you take it in recommended doses and only on a short-term basis. Among the milder side effects are inflamed salivary glands, skin rashes and iodism, which may include symptoms similar to those in a head cold, as well as sore gums, diarrhea, GI upset, metallic taste and burning sensations in the mouth and throat. There may also be allergic symptoms, which are more severe.
Contraindications
If you are sensitive to or allergic to iodine, you should not take KI. You could suffer allergic symptoms like swelling of mouth, tongue, throat, face, hands or feet; difficulty breathing, swallowing or speaking; fever and joint pain. Severe symptoms may represent a medical emergency. If you have an infant younger than 1 month old, give it only one dose of KI and have your doctor monitor thyroid hormone levels; more than one dose may depress your baby's thyroid gland and cause hypothyroidism.
Additional Information
According to the Centers for Disease Control, you can buy KI in either liquid or tablet form at a pharmacy without a prescription. Tablets are available in 65 mg for children or 130 mg for adults. Instructions are for one dose in 24 hours. Only if public health or emergency management officials recommend more doses after that should an adult take them, but you should not take repeated doses if you are pregnant or breastfeeding.
