A message from our pharmacist
With the recent earthquake in Japan and subsequent nuclear reactor explosions, there has been a heightened concern over radiation exposure and an increased interest in taking potassium iodide (also referred to as KI) to protect against the effects of radiation. While potassium iodide has been proven to reduce your risk of thyroid damage during a radiation emergency, it doesn't protect other body organs from radiation poisoning. We feel it's important to understand the role of potassium iodide as a treatment.
About potassium iodide
Potassium iodide occurs naturally in some food sources. Once it's absorbed by the body, it's concentrated in the thyroid gland which uses the iodide to produce thyroid hormones. After a nuclear disaster, radioactive iodine could be present in high concentrations in the environment. When your body absorbs it, your thyroid can become saturated since it can't distinguish between potassium iodide and radioactive iodine. It's this high concentration of radioactive iodine in the thyroid that can cause radiogenic thyroid cancer. Typically, people under 40 and children are at the greatest risk of developing thyroid cancer after radiation exposure.
Following the Chernobyl nuclear reactor disaster in 1986, we learned the thyroid can be protected against radiation-induced thyroid cancer if potassium iodide (KI) is taken immediately before, during or possibly 3 to 6 hours after radiation exposure. However, it's recommended to be taken as late as 48 hours post exposure. After administering potassium iodide, your thyroid becomes saturated and is unable to absorb the radioactive iodine.
The typical recommended dose of potassium iodide for radiation exposure is 130mg per day for adults (12 years and older and over 150lbs), and 65mg for school age children (ages 3-18 and under 150lbs). Repeated use of potassium iodide isn't recommended in pregnant women, infants or during lactation because the risks associated with it outweigh the protective benefits.
It's important to note that prolonged use of potassium iodide can cause hypothyroidism. Potassium iodide can also cause adverse reactions such as goiter, thyroid adenoma, joint pain, fever and lymph node enlargement. Other adverse reactions include gastrointestinal bleeding, confusion, irregular heartbeat, numbness, tingling, unusual pain or weakness in hands or feet and unusual tiredness. Potassium iodide isn’t recommended if you have impaired kidney function, dehydration, bronchitis, hyperthyroidism or tuberculosis. Consult a healthcare provider before taking it if you're pregnant or nursing. You should also avoid taking potassium iodide if you're allergic to iodides or shellfish. Taking potassium iodide unnecessarily is not recommended.
Sources or forms of potassium iodide
Foods rich in iodine
- Sea Spaghetti
Applied Therapeutics, Lippincott Williams & Wilkins, 2005
Drug Facts and Comparisons
Harrison's Principals of Internal Medicine 16th Edition
Drugs in Pregnancy and Lactation, Lippincott Williams & Wilkins, 2005