Potassium Iodide and the Distribution Program

picture of liquid potassium iodide

What is potassium iodide?

Potassium iodide, also known as KI, is a form of iodine. Classified as a drug approved for over-the-counter sale, potassium iodide has been determined by the U.S. Food and Drug Administration (FDA) to be a safe and effective method to block exposure to one product of a nuclear release — radioactive iodine. Radioactive iodine, either inhaled or ingested through contaminated food or milk, can increase the risk of developing thyroid cancer.

Treatment guidance from the FDA (November 2001) confirms that the benefits of potassium iodide far outweigh the rare risks of serious side effects. This is especially true for children, who are more likely than adults to develop thyroid cancer following exposure to radioactive iodine. FDA’s new guidance is based on a comprehensive review of studies conducted after the Chernobyl nuclear reactor accident in 1986.

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How does potassium iodide protect against thyroid cancer?

Certain forms of iodine help your thyroid function properly. Most people get the iodine they need from foods like fish and iodized salt. The thyroid is designed to absorb and store iodine, but it can hold only so much, and will just as readily absorb non-radioactive potassium iodide as radioactive iodine. Because of this, one dose of potassium iodide, which is not harmful to the thyroid, works by filling the gland so it cannot take up any radioactive iodine.

For best protection, one dose of potassium iodide should be taken before or at the time of exposure, although it may still lower risk of thyroid cancer even if taken three or four hours following exposure.

IMPORTANT – The protection offered by potassium iodide is very specific. It protects one organ (thyroid gland) from one type of radiation (radioactive iodine). Emergency directives such as evacuation, staying indoors, or restricting the use of contaminated food and milk are designed to minimize human exposure to all types of harmful radiation that could be released in a nuclear emergency.
Taking potassium iodide is no substitute for following emergency directives.

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Who should NOT take potassium iodide?

What is the recommended dose?

The Nuclear Regulatory Commission has supplied Vermont with Anbex 130 milligram (mg) and Thyrosafe 65 mg size tablets, which are scored so they can easily be cut in half. An oral solution (Thyroshield) is also available for children in schools or childcare settings.

Potassium iodide (KI) should not be administered to children unless directed to do so by public health officials in the event of a radiological emergency at Vermont Yankee, and then only at dosages recommended by the Food and Drug Administration.

FDA Potassium Iodide Dosage Recommendations

Age

KI dose
(mg)

# of 130 mg
tablets

# of 65 mg
tablets

Oral solution
1 ml = 65mg

Adults over 18 years

130 mg

1

2

2 ml

Pregnant or lactating women

130 mg

1

2

2 ml

Children over 3 years to 18 years*

65 mg

1/2

1

1 ml

Children 1 month to under 3 years

32 mg

1/4

1/2

0.5 ml

Children under 1 month

16 mg

1/8

1/4

0.25 ml

*Adolescents approaching adult size (equal to or greater than 154 pounds) should receive the full adult dose (130 mg tablet or 2 ml solution)

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Special instructions for administering KI to children

For children over age 3 years to 18 years – for children weighing less than 154 pounds – the correct dose is 65 mg of KI.

Directions for the oral solution:
Using the dropper provided inside the ThyroShield package, draw up 1 milliliter (ml) of liquid potassium iodide. Drop into paper cup for child to swallow.

Directions for the tablet form:
Check packaging to determine the size of the tablet in mg and refer to the dose chart above.

If administering the 130 mg tablet, the tablet will need to be cut in half. On a firm, hard surface, using a sharp knife, cut the tablet in two. For the younger children in this age group who may not be able to swallow a tablet, powder may be a better alternative.

Put either the 65 mg tablet or one-half of a 130 mg tablet in a cereal bowl and, using the back of a teaspoon, crush the tablet into a fine powder. Add the powder to applesauce, pudding, water or milk. Stir or shake to make sure the powdered tablet mixes in thoroughly and administer immediately. (In a liquid, the powder settles out in a minute or so. If this happens, mix again.)

For children 1 month to under 3 years –
the correct dose for this age group is 32 mg of KI.

Directions for the oral solution:
Using the dropper provided inside the ThyroShield package, draw up 0.5 ml of liquid potassium iodide. Transfer the solution to a cup for the child to drink.

Directions for the tablet form:
Check the packaging to determine the size of the tablet and refer to dose chart above. The 65 mg tablet is preferable for this age group. If administering the 130 mg tablet, the tablet will need to be cut into one-quarter (1/4) its original size. If administering the 65 mg tablet, cut into one-half. Follow instructions above if the child needs to have the pill crushed into a fine powder.

For infants up to 1 month old – the correct dose is 16 mg of KI.

Directions for the oral solution:
Using the dropper provided in the ThyroShield package, draw up 0.25 ml of liquid potassium iodide. Place the liquid KI into an ounce of water and add this solution to a nursing bottle for feeding through a nipple.

Directions for the tablet form:
For newborns, the dose is one-eighth (1/8) of a 130 mg tablet or one-quarter (1/4) of a 65 mg tablet. Place the cut tablet into a cereal bowl and, using the back of a teaspoon, crush the tablet into a fine powder. Put the powder into a baby bottle, add one to two ounces of formula or breast milk and shake immediately. (The powder settles  out in a minute or so. If this happens, mix again.)

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In case of an overdose or allergic reaction

Call your doctor or the New England Poison Center at 800-222-1222.

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How long before or after exposure should KI be taken?

Potassium iodide is effective if taken shortly before (about 30 minutes) or after (up to 3 hours) exposure to radioactive iodine in the air. Vermont Department of Health officials will work to anticipate possible radiological releases from Vermont Yankee and issue orders for KI administration to fit into this time frame.

Potassium iodide is but one protective measure for a radiological release from Vermont Yankee. Other important protective measures include evacuation of potentially affected areas or taking shelter within your home or workplace, should orders to do so be given by health officials. Talk to your town’s emergency director for more information about radiological emergency response, or to volunteer to help in the event of an emergency.

Should you have expired potassium iodide (the labeled expiration date is earlier than the date you are reading the label), bring it to the Health Department’s Brattleboro office for disposal. The office is located at 232 Main Street, Suite 3.

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