The newly released (November, 2001) FDA document entitled Potassium Iodide as a Thyroid Blocking Agent in Radiation Emergencies makes it plain that: For optimal prophylaxis, KI should therefore be dosed daily, until a risk of significant exposure to radioiodines by either inhalation or ingestion no longer exists." Many others also believe that you should not stop until you have been, for at least a day or more, out of the possibility to ingest or inhale any more radioiodine.

Since KI protects for approximately 24 hours, it should be dosed daily until the risk no longer exists. Priority with regard to evacuation and sheltering should be given to pregnant females and neonates because of the potential for KI to suppress thyroid function in the fetus and neonate. Unless other protective measures are not available, we do not recommend repeat dosing in pregnant females and neonates.

You will probably be told not to take the drug for more than 10 days." The reason for this cut-off date is the presumption that, in a nuclear power plant radiation accident, if the radioiodine was gaseous or an aerosol it would also probably be fully dispersed by this time. If it was not yet dispersed and/or there was ongoing continuing radioiodine releases, then the affected population would have likely been evacuated to a safer location well within that 10 day time frame.

There are two FDA-approved products: "Thyro-Block" (MedPointe, Inc.), approved prior to 1/1/82, and "Iosat" (Anbex, Inc.), approved 10/14/83. These products are approved for over-the-counter (OTC) use as a thyroid-blocking agent in radiation emergencies.

Persons with known iodine sensitivity should avoid KI, as should individuals with dermatitis herpetiformis and hypocomplementemic vasculitis, extremely rare conditions associated with an increased risk of iodine hypersensitivity. Individuals with multinodular goiter, Graves' disease, and autoimmune thyroiditis should be treated with caution -- especially if dosing extends beyond a few days.

KI works best if used within 3-4 hours of exposure. Although FDA has not made specific recommendations for individual purchase or use of KI, the Nuclear Regulatory Commission has contracted to purchase KI for states with nuclear reactors and states that have population within the 10-mile emergency planning zone, e.g., Delaware or West Virginia.

iOSAT™ Tablets are FDA approved for seven years and should be stored unopened in a dry environment at room temperature.

Rad Block, No-Rad, LifeExtension (LEF), KI4U, NukeProtect, ProKI and KIO3 Potassium IodATE (different spelling, different drug) are not FDA Approved for radiation emergencies. The FDA has sent cease and desist letters to some of these manufacturers who recommend their product for radiation emergencies. Other products (like Rad Block) state they are manufactured in an "FDA licensed and approved over-the-counter (OTC) drug manufacturing facility".

The FDA guidance prioritizes groups based on age, which primarily determines risk for radioiodine-induced thyroid cancer. Those at highest risk are infants and children, as well as pregnant and nursing females, and the recommendation is to treat them at the lowest threshold (with respect to predicted radioactive dose to the thyroid). Anyone over age 18 and up to age 40 should be treated at a slightly higher threshold.

Thyroidal side effects of KI at recommended doses rarely occur in iodine-sufficient populations such as the U.S. As a rule, the risk of thyroidal side effects is related to dose and to the presence of underlying thyroid disease (e.g., goiter, thyroiditis, Graves'). FDA recommends adherence to the Guidance for intervention threshold and dose, though we recognize that the exigencies of any particular emergency situation may mandate deviations from those recommendations.

with any drug, physicians should understand the risks and benefits of KI before recommending it or prescribing it to patients. We recommend that physicians read our guidance for more information. It is available on the FDA website at http://www.fda.gov/cder/guidance/index.htm under procedural guidance #18. The FDA guidance discusses the rationale and methods of safe and effective use of KI in radiation emergencies.

FDA will continue to work with interested pharmaceutical manufacturers to assure that high quality, safe, and effective KI products are available for purchase by consumers, by state and local authorities, and by federal government agencies electing to do so.

Prepared Potassium Iodide (KI) solutions are only available by prescription, such as Lugol's Solution. However, anyone can buy Potassium Iodide USP at a chemical supply house (and even some larger photo supply outlets) and readily mix up their own Potassium Iodide (KI) solutions that is every bit as effective as the tablets.

Unfortunately, there is no simple or standard response that could ever be applicable to all American families with their wide variety of concerns, locations, and situations. There are too many variables involved, both in the nature of the possible nuclear radiation threats and your particular family exposure to those threats.

Potassium iodide (KI) should only be taken in a radiation emergency that involves the release of radioactive iodine, such as an accident at a nuclear power plant or the explosion of a nuclear bomb. A “dirty bomb” most likely will not contain radioactive iodine. A person who is internally contaminated with radioactive iodine may experience thyroid disease later in life. The thyroid gland will absorb radioactive iodine and may develop cancer or abnormal growths later on.