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Nuclear Attack! – Is Potassium Iodide the Answer?

Caroline Suh, Pharm.D.
Drug Information Practice Resident
University of Maryland School of Pharmacy

September 11th has left many Americans feeling afraid and confused. Everyday the news is filled with stories about possible acts of terrorism, anthrax scares and nuclear threats. People are worried about protecting themselves and their loved ones against future terrorist attacks.

What is the Government Doing to Protect You?
Local and federal governments have started buying millions of doses of potassium iodide to help protect people from radiation in case of an attack on nuclear power plants. One plan is to give potassium iodide tablets to people who live within 10 miles of a nuclear power plant because they are most at risk. So far, only a few states have stockpiles of potassium iodide including Vermont, Maine, Alabama, Tennessee and Arizona. New Hampshire, New York, Maryland and Massachusetts are also interested in getting supplies of potassium iodide.

Authorities are trying to figure out the best way to prepare for a nuclear attack such as how to get potassium iodide to people in time. This is important because potassium iodide needs to be taken as soon as possible for the best effect.

Are You Prepared?
During this time of fear and confusion, it is important to be cautious and to stay informed. Potassium iodide is approved by the Food and Drug Administration (FDA) to protect both children and adults against thyroid cancer in case of a nuclear emergency. You can buy potassium iodide without a prescription, but it may not be safe for everyone to take. If there is a nuclear emergency, you won't have a lot of time to read the label on the bottle. You need to know which dose to take and all the important information you need to take potassium iodide safely and effectively.

The bottom line is that there are both risks and benefits to taking potassium iodide.

Will Potassium Iodide Protect You?
Potassium iodide only helps to protect the thyroid gland from radioactive iodine. This is the kind of radiation that is released into the air in a nuclear attack or accident in a power plant. When people breathe in radioactive iodine or eat contaminated food, it can build up in the thyroid gland and increase the risk of getting thyroid cancer. The thyroid gland uses a lot of iodine, so it is the part of your body that is most affected by radiation. After the nuclear accident in Chernobyl, the number of people with thyroid cancer was 100 times higher than it had been before the accident.

The thyroid gland can hold only a certain amount of iodine. Potassium iodide protects the thyroid gland by filling it with a safe form of iodine so that the radioactive iodine cannot get in. If the radioactive iodine can't get into your thyroid, your body can get rid of it more quickly and decrease your risk of getting cancer.

Potassium iodide is not a "magic pill" that can protect against all the harmful effects of radiation. It can only help protect you against thyroid cancer. Potassium iodide will not protect you against "dirty bombs" (also called "suitcase bombs"). This is because dirty bombs do not release radioactive iodine. Potassium iodide combined with other safety measures can give you the most protection in a nuclear emergency.

How Do You Take Potassium Iodide?
For the most protection, potassium iodide should be taken immediately at the beginning of a nuclear emergency. This will help prevent radioactive iodine from building up in your thyroid gland.
Potassium iodide can still give you some protection even if you take it 3 to 4 hours after being exposed to radiation. The longer you wait, the less protection you will have.

Here are some important facts:
ß One dose of potassium iodide can protect your thyroid gland up to 24 hours. Don't take more than one dose of potassium iodide a day. It will not give you more protection because the thyroid gland can only hold a certain amount of iodine. It will only increase your chances of getting side effects.

The FDA recommends that potassium iodide tablets be taken until the risk of radiation has passed and/or until other safety measures have been set up.

Potassium iodide comes in two different strengths of tablets. The dose of potassium iodide that is safe and effective for you and your family depends on age and weight. The FDA recommends the following doses but always check with your doctor to make sure that it is safe for you to take potassium iodide. For example, if you are allergic to iodine, have kidney or thyroid problems, or are pregnant or breast-feeding you may not be able to take potassium iodide or you may need a different dose.

Strength of Tablet
130 mg
65 mg
Adults 41yrs and older
1 tablet
2 tablets
Adults 19 to 40 yrs
Pregnant or breastfeeding women
Teenagers 13 to 18 yrs
_ tablet
1 tablet
Children 4 to 12 yrs
Children 2 months to 3 yrs
_ tablet
_ tablet
Newborns to 1 month
1/8 tablet
_ tablet

These doses can be confusing and hard to understand. During a nuclear emergency, you may not have time to figure out how much potassium iodide to take. To make sure you know which doses are safe for you and your family, talk to your doctor and pharmacist ahead of time.

Normally, potassium iodide should not be used in very young children or in women who are pregnant of breast-feeding. But in a nuclear emergency, you and your doctor may decide that the benefits of 1 dose of potassium iodide outweigh the risks.

Like all medicines, potassium iodide can cause side effects. The most common side effects of potassium iodide are tiredness, skin rash, nausea/vomiting, and upset stomach. Some people may have an allergic reaction to potassium iodide with symptoms such as shortness of breath, fever, aches and pains or a rash. These symptoms can occur right away or within a few hours after taking potassium iodide. If this happens to you, stop taking potassium iodide and talk to your doctor or public health official as soon as you can.

Potassium iodide can affect how other medicines work. Talk to your doctor and pharmacist to find out if you are taking medicines that would be unsafe to take with potassium iodide. This way you can avoid any harmful drug interactions. It is better to have this important information before you need it in an emergency.

Where Can You Get Potassium Iodide?
Potassium iodide is an over-the-counter medicine. This means you don't need a prescription to buy it. Anbex, Inc (Iostat‰) and Ready Prep (Rad Block‰) are two of the companies that make potassium iodide tablets. You can buy potassium iodide tablets online or in your local pharmacy. Pharmacies don't usually stock potassium iodide tablets but they can order them for you.

Don't Fall Victim to a False Sense of Security
Think of potassium iodide as a life jacket. You need to wear a life jacket to protect you from drowning when you are in a boat. In case of an accident, a life jacket can keep you afloat but you will need the help of a lifeguard to bring you safely back to shore.

Like the life jacket, potassium iodide can give you some protection at the very beginning of a nuclear emergency. And just like the lifeguard, public health officials will provide you with the next level of protection by setting up oth

  1. There are still so many unanswered questions that can affect the decisions made during a nuclear emergency. For example:
  2. What effect will wind patterns have on the spread of radioactive iodine on the day of the attack? For example, if a nuclear plant on the east coast were hit, how effective would the winds be in carrying it out to sea? What would happen if a nuclear power plant on the west coast were hit? Would the jet stream winds carry radioactive iodine to the surrounding states?What effect will weather patterns (such as rain or snow) have on the spread of radioactive iodine?
  3. Is a 10-mile emergency zone big enough? How much is it affected by wind and weather patterns?
  4. Should potassium iodide be given to people outside the 10-mile emergency zone?
  5. How will the government prepare for a planned nuclear attack on several cities at once? How will the consumer know which direction to evacuate?er safety measures that will include shelter and evacuation plans and how to protect the food supply.

Prepare yourself ahead time. Talk about the risks and benefits of taking potassium iodide with your doctor and pharmacist. Make sure you know that it is safe for you to take potassium iodide. And, know which doses are safe for you and your family to take. Talk to public health officials about how to take shelter and evacuate during a nuclear emergency.

Remember, potassium iodide can help you stay afloat, but other important safety measures will get you onto dry land.

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