Potassium Iodide (KI)

For people exposed to radioactive material released during a radiation incident

Potassium Iodide (KI) tablets may help prevent thyroid cancer in people exposed to radioactive material released during a radiation incident. The thyroid gland is the part of the body that is most sensitive to radioactive iodine. KI tablets do not prevent any other radiation-related cancers. Because radiation-induced thyroid cancers are slow-growing, sometimes taking years to develop, KI tablets may be most effective for children and young adults.

People should only take KI (potassium iodide) on the advice of public health officials during an active incident.

Risks of KI

While KI is good at preventing thyroid cancer when exposed to radiation, there are still risks you should be aware of, as with all medication. The risks of KI are the following:

Less Common

Hives
Joint pain
Swelling of arms, face, legs, lips, tongue, and/or throat
Swelling of lymph glands

With Long Term Use

Burning of mouth or throat
Confusion
Headache (severe)
Increased watering of the mouth
Irregular heartbeat
Metallic taste
Numbness, tingling, pain, or weakness in hands or feet
Soreness of teeth and gums
Sores on skin
Symptoms of head cold
Unusual tiredness
Weakness or heaviness of legs

If you are experiencing any of these side effects, please contact your doctor as soon as possible.

Potassium Iodide (KI) Distribution

The St. Mary’s County Health Department (SMCHD) routinely distributes KI tablets to county residents living or working within the 10-mile emergency protection zone (EPZ) of the Calvert Cliffs Nuclear Power Plant to have on hand in case of emergency.

Who is Eligible?

St. Mary’s County Residents living or working within the 10-mile EPZ (6 & 7). This area includes the following zip codes:

20659 – Mechanicsville
20636 – Hollywood
20619 – California
20653 – Lexington Park

Distribution

Potassium Iodide (KI) tablets will be routinely offered to eligible community members. The St. Mary’s County Health Department will issue a notice when the next distribution event is scheduled.

Appointments for Pick-Up

To make an appointment for pick-up at the SMCHD main office in Leonardtown, please email smchd.dpr@maryland.gov.

Recommendations for Taking KI Tablets

The following recommendations are for general information purposes. People should only take KI (potassium iodide) on the advice of public health or emergency management officials during an active incident. Click here for the SMCHD Informational Brochure on when and how to take KI (En Español).

In the case of an emergency incident, the community will be notified by the St. Mary’s County Government and St. Mary’s County Health Department via the CodeRED Emergency Notification System as well as through local news, radio, and social media outlets.

A single dose of KI (potassium iodide) protects the thyroid gland for 24 hours. A one-time dose at recommended levels is usually all that is needed to protect the thyroid gland. In some cases, people can be exposed to radioactive iodine for more than 24 hours. If that happens, public health or emergency management officials may tell you to take one dose of KI (potassium iodide) every 24 hours for a few days.

Infants

Infants have the highest risk of getting thyroid cancer after being exposed to radioactive iodine.

When recommended by public health/emergency officials, infants, including breast-fed infants, need to be given a single dose of KI (recommended dosage for infants)
More than a single dose may lead to later problems with normal development
In cases where more than one dose is necessary, medical follow-up with your pediatrician may be recommended
Liquid dosing instructions
Children over 1 month through 3 years of age—32 mg once a day until there is no longer a significant risk of radiation

Children

When recommended by public health/emergency officials, all children who are internally contaminated (or likely to be) with radioactive iodine should take the recommended dose of KI unless they have known allergies to iodine.

Children 3-17 years of age (less than 154lbs )—65 mg once a day until there is no longer a significant risk of radiation

Adults (18-40)

When recommended by public health/emergency officials, adults between the ages of 18 and 40 who are internally contaminated (or likely to be) with radioactive iodine should take the recommended dose of KI. Young adults are less sensitive to the effects of radioactive iodine than children.

Adults or teenagers 154+ lbs —130 mg once a day until there is no longer a significant risk of radiation

Pregnant Women

Because all forms of iodine cross the placenta, pregnant women should take KI during an active incident to protect the growing fetus. Pregnant women who are internally contaminated, or likely to be, should take only one dose of recommended KI for adults.

Breastfeeding Women

Women who are breastfeeding and who are internally contaminated or likely to be, should take only one dose of recommended KI for adults.

Adults (40+)

Generally, adults older than 40 years should not take KI. Public health/emergency officials may recommend KI for this group if the emergency event/contamination of radioactive iodine is expected to be severe.

Adults older than 40 years have the lowest chance of developing thyroid cancer or thyroid injury after contamination with radioactive iodine
Adults older than 40 are more likely to have allergic reactions to or adverse effects from KI
Follow recommendations from public health/emergency officials for this specific age group

Pets

Consult your veterinarian before giving your pet Potassium Iodide (KI), keeping the following in mind:

KI only protects the thyroid from radioactive iodine. It does not shield against other harmful radiation that may be released during a nuclear event.
- Pet decontamination may still be needed.
Correct dosing is crucial. Like all medications, improper dosing can be harmful to your pet. Speak with your veterinarian about appropriate dosage recommendations.
Young, growing animals are more vulnerable to radiation. Radiation exposure poses the greatest risk to younger animals due to their developing systems.
Timing is critical. KI must be administered before or within 4 hours of exposure to be effective.
KI availability for pets may be limited. Most veterinarians and pharmacies do not routinely stock KI, though they may begin to do so if demand increases. KI can also be specially ordered through your veterinarian or local pharmacy.
Do not give KI to pets sensitive to iodine. Always confirm with your veterinarian if KI is appropriate for your pet, especially if they have an iodine sensitivity.

For more information, please contact your veterinarian.