Potassium Iodide (KI) Key Facts 4

Potassium Iodide (KI) Key Facts 4 How often should I take KI? A single dose of KI protects the thyroid gland for 24 hours. A one-time dose at the levels recommended in this fact sheet is usually all that is needed to protect the thyroid gland. In some cases, radioactive iodine might be in the environment for more than 24 hours. If that happens, local emergency management or public health officials may tell you to take one dose of KI every 24 hours for a few days. You should do this only on the advice of emergency management officials, public health officials, or your doctor. Avoid repeat dosing with KI for pregnant and breastfeeding women and newborn infants. Those individuals may need to be evacuated until levels of radioactive iodine in the environment fall. Taking a higher dose of KI, or taking KI more often than recommended, does not offer more protection and can cause severe illness or death. Medical conditions that may make it harmful to take KI Taking KI may be harmful for some people because of the high levels of iodine in this medicine. You should not take KI if • you know you are allergic to iodine (If you are unsure about this, consult your doctor. A seafood or shellfish allergy does not necessarily mean that you are allergic to iodine.) or • you have certain skin disorders (such as dermatitis herpetiformis or urticaria vasculitis). People with thyroid disease (for example, multinodular goiter, Graves’ disease, or autoimmune thyroiditis) may be treated with KI. This should happen under careful supervision of a doctor, especially if dosing lasts for more than a few days. In all cases, talk to your doctor if you are not sure whether to take KI. What are the possible risks and side effects of KI? When public health or emergency management officials tell the public to take KI following a radiologic or nuclear event, the benefits of taking this drug outweigh the risks. This is true for all age groups. Some general side effects caused by KI may include intestinal upset, allergic reactions (possibly severe), rashes, and inflammation of the salivary glands. When taken as recommended, KI causes only rare adverse health effects that specifically involve the thyroid gland. In general, you are more likely to have an adverse health effect involving the thyroid gland if you * take a higher than recommended dose of KI, * take the drug for several days, or * have pre-existing thyroid disease.