FDA urges ‘dirty bomb’ treatment - Paint pigment Prussian blue may be radiation antidote

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WASHINGTON, Jan. 31 — Federal health officials say a compound long used as the artist’s pigment Prussian blue could be an important antidote to a “dirty bomb” attack, and they are calling for drug companies to quickly seek permission to manufacture some of it.

Currently, an Energy Department-funded facility in Oak Ridge, Tenn., has the nation’s only supply of Prussian blue in pill form, and that supply is limited.

	       THE FOOD and Drug Administration action on Friday marks a big step toward radiation specialists’ call for a stockpile of the antidote — all but guaranteeing sales approval for manufacturers who meet some fairly simple conditions.

       Currently, an Energy Department-funded facility in Oak Ridge, Tenn., has the nation’s only supply of Prussian blue in pill form, and that supply is limited.

       That facility, the Radiation Emergency Assistance Center/Training Site — known as REACTS — helps with radiation accidents around the world. REACTS buys experimental Prussian blue pills from a German company, and had urged FDA to approve regular sales of the compound so it would easier to stockpile more in case of a terrorist attack.

       Friday, the FDA took a major step toward doing that by declaring Prussian blue an effective treatment for exposure to certain forms of radioactive cesium and thallium.

       Those materials are commonly used, at low doses, in medical treatment and diagnosis. But high levels can be deadly, and they are among the materials that officials worry might be used in a “dirty bomb” — a device that isn’t nuclear but that uses conventional explosives to disperse radioactive material.

COMPOUND CUTS EXPOSURE RISKS        The FDA evaluated reports of a 1987 accident in Brazil where 250 people were contaminated with cesium-137 that had been abandoned after use in a cancer clinic, plus a handful of smaller accidental exposures to radioactive cesium and thallium and a toxic but nonradioactive form of thallium.

       Prussian blue cut in half the time the body was contaminated, with minor side effects such as constipation, the FDA concluded. The mineral compound, known chemically as ferric hexacyanoferrate, worked by binding to the chemicals in the gut so they could be eliminated instead of absorbed.

       FDA’s unusual declaration removes a significant burden from any company considering making Prussian blue pills — they wouldn’t have to prove it’s a safe or effective treatment. Instead, interested manufacturers merely would have to prove they can properly brew the right dose, steps FDA drug chief Dr. Janet Woodcock called simple for any pharmaceutical company.

	       Currently, there is only one commonly available medication for protection against radiation, a drug called potassium iodide that people who live near nuclear reactors often keep on hand in case of an attack or accident. It has just one use — to prevent thyroid cancer by shielding the thyroid gland from exposure to radioactive iodine. It blocks no other type of radiation, and protects no other body part.

Radiation sickness

MSNBC answers your questions on the health effects of radiation exposure. How does radiation affect the body? Damage can be caused by brief exposure to high levels of radiation or long-term exposure to low levels. The harmful effects depend on the amount and duration of exposure. A single, rapid dose of radiation can be fatal. But the same dose given over a period of weeks or months may have little impact. The effects also depend on how much of the body is exposed. More than 6 grays (a gray is the amount of energy absorbed during exposure) of radiation usually cause death when the radiation is distributed over the entire body. However, when beamed to a small area, as in radiation therapy for cancer, three or four times this amount can be given safely.

What syndromes can result?

• Cerebral (brain) syndrome: This syndrome can result if the total dose of radiation is extremely high (more than 30 grays). The first symptoms, nausea and vomiting, are followed by listlessness, drowsiness and sometimes coma. Tremors, convulsions and death occur within a few hours.
• Gastrointestinal syndrome: This results from smaller doses of radiation (4 grays or more). Symptoms include severe nausea, vomiting and diarrhea, leading to severe dehydration. This syndrome is caused by the death of cells lining the GI tract. Death occurs after bone marrow failure, which usually takes place two to three weeks later.
• Hematopoietic syndrome: This affects the bone marrow, spleen and lymph nodes. It develops after exposure to 2 to 10 grays of radiation and begins with a loss of appetite, nausea and vomiting. The symptoms are most severe 6 to 12 hours after exposure and may subside completely in 24 to 36 hours. Death occurs when the blood-producing cells in the lymph nodes, spleen and bone marrow begin to waste away, leading to a severe shortage of red and white blood cells.

How can I minimize radiation exposure? There are three factors that can minimize radiation exposure to your body: Time, distance and shielding.

• Time: Most radioactivity loses its strength fairly quickly. Limiting the time spent near the source of radiation reduces the amount of radiation exposure you will receive. Following an accident or attack, authorities will monitor any release of radiation and determine what protective actions to take.
• Distance: The more distance between you and the source of the radiation, the less radiation you will receive. In the event of a serious accident or attack, local officials will likely call for an evacuation, thereby increasing the distance between you and the radiation.
• Shielding: Like distance, the more dense the materials between you and the source of the radiation, the better. This is why local officials may advise you to remain indoors if an accident occurs. In some cases, the walls in your home or workplace would be sufficient to protect you for a short period of time.

What were the effects from Three Mile Island? Major radiation exposure did not result from the Three Mile Island accident. In fact, a person living within one mile of the plant received slightly less radiation than the average person receives from X-rays in one year. People living near the Chernobyl plant were exposed to considerably more radiation than those near Three Mile Island. More than 30 people died and many more were injured.

Sources: The Merck Manual, FEMA