Potassium iodide protects your thyroid gland from harmful radioactive iodine after a nuclear emergency. This helps reduce your risk of cancer and other health problems caused by radioactive exposure. Potassium iodide is available as a prescription oral solution for adults or as over-the-counter (OTC) tablets for adults and children. The dose depends on your age and the recommendations of public health officials or your prescriber. Side effects can include nausea, diarrhea, fever, and a metallic taste in the mouth.
Protects the thyroid gland from radioactive iodine exposure during nuclear emergencies
Potassium iodide is an antithyroid medication. The medication works by blocking harmful radioactive iodine from building up in the thyroid gland. It forces the thyroid gland to absorb the stable iodine in the medication, filling it up so it can't take in radioactive iodine.
Source: DailyMed
Side effects that you should report to your care team as soon as possible:
Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):
Tablets are available over the counter at your pharmacy
Might only need to take one dose
Can be used by most people, including adults and children of all ages
Can cause an allergic reaction
Can leave a metallic taste in your mouth
Need to take it soon after a radiation exposure to get the most benefit
Anyone who is exposed to radioactive iodine can take potassium iodide, but public health officials will guide you on how much to take or if it's needed. Infants, children, and pregnant women are usually at the highest risk of harm from radioactive iodine, but high exposures can put anyone at risk.
Don’t take more potassium iodide than needed, and never more than one dose in 24 hours. Taking extra won’t provide more protection from radiation poisoning and can raise your risk of side effects.
You can take potassium iodide with or without food. But taking it with food or milk might help reduce stomach upset.
Potassium iodide tablets can be crushed to make an oral solution for people with trouble swallowing. Mix the crushed tablets in water then combine with white or chocolate milk, orange juice, flat soda, raspberry syrup, or infant formula. Refer to the instructions on the package to mix the right amount.
Store potassium iodide in a dry place at room temperature. The prescription oral solution can be stored until the expiration date on the bottle. But if you've created an oral solution from crushed tablets, you can store that in the refrigerator for up to 7 days. Protect potassium iodide from light.
Potassium iodide can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Risk factors: Allergy to iodides
You might have an allergic reaction to potassium iodide. This is likely due to the iodide ingredient in the medication. The reaction can cause swelling, trouble breathing or swallowing, skin rash, or fever with joint pain. Be sure to contact a healthcare professional (HCP) or get medical help right away if you develop any of these symptoms.
Risk factors: History of high thyroid hormone levels (hyperthyroidism) | Taking potassium iodide for a long period of time | Young children, newborns, and infants | People who are pregnant or breastfeeding
Potassium iodide can affect how your thyroid gland works. This medication is usually taken for one day, so short-term use is considered safe. But taking it for longer periods might raise the risk for thyroid problems. If you’re pregnant, breastfeeding, or have a child under 1 month old, let your healthcare professional know.
Dosage | Quantity | Price as low as | Price per unit |
---|---|---|---|
30ml of 65mg/ml | 1 bottle | $18.17 | $18.17 |
The dose depends on your age and the recommendations of public health officials or your prescriber. Each tablet and each mL of the oral solution contain 65 mg of potassium iodide.
During a nuclear radiation emergency, adults 18 years and older should take 130 mg by mouth once daily or as instructed by public health officials.
The FDA has recommended additional information on the dosing for other age groups.
Newborns from birth to 1 month: Take 16 mg (¼ of a 65 mg tablet or 0.25 mL solution) by mouth once daily.
Infants and children over 1 month to 3 years: Take 32 mg (½ of a 65 mg tablet or 0.5 mL solution) by mouth once daily.
Children and teenagers over 3 years to 18 years:
Weighing 150 lbs or less: Take 65 mg by mouth once daily.
Weighing more than 150 lbs: Take 130 mg by mouth once daily.
People who are breastfeeding or pregnant: Take the adult dose of 130 mg once daily, but contact your healthcare professional for more instructions.
Allergy to iodides
Nodular thyroid disease with heart disease
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Kesarwani, V., et al. (2022). Hypocomplementemic urticarial vasculitis syndrome or systemic lupus erythematosus in evolution? Cureus.
Mission Pharmacal Company. (2023). Potassium iodide solution [package insert]. DailyMed.
U.S. Food and Drug Administration. (2022). Frequently asked questions on potassium iodide (KI).
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