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Potassium Iodide (KI) Information

  • Published: 2011-03-16 (Revised/Updated 2013-08-01) : Disabled World.
  • Synopsis: Potassium iodide also referred to as KI is a form of salt of non-radioactive iodine in medicinal form

Main Document

Quote: "There are two forms of KI that are FDA approved; liquid and tablets, that may be taken orally after a radiation emergency."

Potassium iodide, also referred to as, 'KI,' is a form of salt of non-radioactive iodine. Stable iodine is an important chemical required by a person's body for it to produce thyroid hormones. The majority of stable iodine in a person's body comes from the foods they consume. KI is a stable iodine in medicinal form.

After a nuclear or radiological event, radioactive iodine might be released into the air and then get breathed by a person into their lungs. Radioactive iodine can also contaminate food supplies and enter into a person's body through the drinks or food they consume. When radioactive materials enter into a person's body through eating, drinking, or breathing it is referred to as, 'internal contamination.' When a person experiences internal contamination, their thyroid rapidly absorbs radioactive iodine. Radioactive iodine that is absorbed by a person's thyroid has the potential to injure this gland. Due to the fact that non-radioactive KI works to block radioactive iodine from being absorbed by a person's thyroid gland, it has the ability to protect the thyroid gland.

Awareness of what KI does not have the ability to do is equally important. KI does not have the ability to prevent radioactive iodine from entering a person's body. KI only has the ability to protect a person's thyroid gland from radioactive iodine - it cannot protect other parts of your body. KI does not have the ability to reverse health effects caused by radioactive iodine once damage to your thyroid has already happened. KI also cannot protect you from radioactive elements other than radioactive iodine.

How Potassium Iodine (KI) Works

A person's thyroid gland does not have the ability to distinguish between stable and radioactive iodine; it will absorb both of them. KI works because it blocks radioactive iodine from entering your thyroid. When you take KI, the stable iodine in the medication is absorbed by your thyroid. KI contains a large amount of stable iodine; your thyroid gland becomes full and doesn't have the ability to absorb any more iodine, whether that iodine is stable or radioactive, over a period of twenty-four hours.

Table salt that is iodized does contain iodine. The amount of iodine in iodized table salt is enough to keep the majority of people healthy under usual conditions. Iodized table salt does not have enough iodine in it to block radioactive iodine from entering your thyroid gland. You cannot use iodized table salt as a substitute for KI.

Understand that KI might not give a person one-hundred percent protection against radioactive iodine. The effectiveness of KI is dependent upon the amount of time that passes between the time a person is contaminated with radioactive iodine and the time they have taken KI. The sooner a person takes KI after being exposed the better. It also depends on how fast the KI is absorbed into the person's bloodstream, as well as the total amount of radioactive iodine the person has been exposed to.

Who Should and Who Should Not Take Potassium Iodine (KI)

Thyroid glands in fetuses and infants are at greatest risk of injury from radioactive iodine. People who have low amounts of iodine in their thyroids, as well as young children, are also at great risk of a thyroid injury. Infants should be given the recommended dosage of KI for babies. The amount of KI they receive through breast milk isn't enough to protect them from exposure to radioactive iodine.

All forms of iodine cross the placenta. Pregnant women should take KI in order to protect the growth of their child. It is important for pregnant women to take only one dose of KI after experiencing internal contamination, or likely contamination, with radioactive iodine. Women who are breastfeeding their child should also only take one dose of KI if they have been internally contaminated. Radioactive iodine rapidly gets into a woman's breast milk and the Centers for Disease Control and Prevention suggest that women who are internally contaminated with radioactive iodine stop breast feeding their child. Instead; women should feed their children baby formula or other food.

The FDA recommends that children who are internally contaminated, or are likely to be, with radioactive iodide take KI unless they are known to have an allergy to it. Children between the ages of newborn to eighteen are the most sensitive to thyroid damage from radioactive iodine. Young adults are less sensitive to the effects of radioactive iodine than young children are. People between the ages of eighteen and forty who are internally contaminated should take the recommended dosage of KI.

People who are over the age of forty should not take KI, unless emergency or public health officials state that contamination with large doses of radioactive iodine is expected. People who are over the age of forty have the least chance of developing thyroid cancer or injury to their thyroid after experiencing internal contamination. People over the age of forty also have the greatest chance of experiencing an allergic reaction to the medication.

Once a radiologic or nuclear event has occurred, emergency or public health officials will inform people if KI or other forms of protective actions are required. Officials might instruct people to stay indoors, such as in their homes, offices, schools, or shelters. People might be ordered to evacuate. Officials may tell people not to eat certain foods, or not to drink certain beverages until clean supplies can be brought in. It is important to listen to the instructions health or emergency officials provide because it can help you to lower the amount of radioactive iodine entering your body, or lower the risk of severe injury to your thyroid gland.

Potassium Iodine (KI) Dosages

There are two forms of KI that are FDA approved; liquid and tablets, that may be taken orally after a radiation emergency. The tablets are available in two strengths; 65 mg., and 130 mg. The tables are scored so they can be cut into smaller doses. Each milliliter of the liquid form has 65 mg. Of KI.

The FDA states the doses below are appropriate after a person experiences internal contamination or suspected internal contamination:

  • Women who are breastfeeding should take the adult dose of 130 mg.
  • Adults should take 130 mg (one 130 mg tablet OR two 65 mg tablets OR two mL of solution).
  • Children between 3 and 18 years of age should take 65 mg (one 65 mg tablet OR 1 mL of solution).
  • Children who are adult size (greater than or equal to 150 pounds) should take the full adult dose, regardless of their age.
  • Infants and children between 1 month and 3 years of age should take 32 mg (1/2 of a 65 mg tablet OR 1/2 mL of solution). This dose is for both nursing and non-nursing infants and children.
  • Newborns from birth to 1 month of age should be given 16 mg (1/4 of a 65 mg tablet or 1/4 mL of solution). This dose is for both nursing and non-nursing newborn infants.

One dose of KI will protect a person's thyroid gland for a period of twenty-four hours. A recommended dose is often all that is required to protect a person's thyroid gland, although sometimes radioactive iodine can remain in the environment for greater than twenty-four hours. Should this occur, emergency or health officials might instruct people to take one dose of KI every twenty-four hours over a period of a few days. People should only take KI over this period of time if they are instructed to do so by emergency or health officials, or a doctor. It is important to avoid repeating doses of KI if you are pregnant or breast feeding, or have newborn infants. Women who are pregnant, breast feeding, or have newborn infants might need to be evacuated until the levels of radioactive iodine fall to acceptable levels.

Taking more KI than is recommended, or a higher dose, doesn't give you more protection from radioactive iodine. In fact - it can cause you severe illness, or even death. There are also medical conditions that can make it harmful to take KI.

The high levels of iodine in KI can harm people if they are allergic to iodine. People with particular skin disorders, such as uticaria vasculitis, or dermatitis herpetiformis, can also be harmed by taking KI. It is important to note that if you have a shellfish or seafood allergy, it does not necessarily mean that you are allergic to iodine. If you are not sure if you can take KI, be sure to consult a health care profession if you can before taking it.

Potential Side-Effects of Potassium Iodine (KI)

The benefits of taking KI after a nuclear or radiologic event greatly outweigh the risks; something that is true for people from every age group.

Side-effects of KI consumption may include:

  • Rashes Intestinal upset
  • Salivary gland inflammation
  • Allergic reactions, potentially severe

KI rarely causes adverse affects on a person's thyroid gland when taken as recommended. Generally, people are more likely to experience adverse effects on their thyroid gland if they take a higher dose of KI than recommended, have a pre-existing thyroid disease, or have taken KI for a number of days.

Newborns who are less than a month old and receive more than one dose of KI are at specific risk for developing a condition referred to as, 'hypothyroidism,' involving thyroid hormone levels that are too low. When hypothyroidism is not treated, it can cause damage to the newborn's brain. Newborn's who receive KI need to have their thyroid hormone levels checked as well as monitored by a physician. Repeat doses of KI in newborns is something that should be avoided.

Related Information:

  1. Statement Regarding Fears of Radiation Exposure to North America
  2. Radiation Sickness Information and Facts


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