As Japan races to avoid a nuclear disaster, some Americans and companies in the United States are scrambling to obtain potassium iodide, a drug that can protect people from radiation-induced thyroid cancer.
“We’ve sold more in the past three days than we have in the past three years,” said Jim Small, president of the American arm of Recipharm, a Swedish company that is a major supplier of potassium iodide.
While some orders are going to individuals, others are going to companies that want to provide the products to their employees in Japan, the manufacturers said. Mr. Small said that Recipharm was trying to borrow tablets from governments of countries far from Japan to send there. Alan Morris, president of Anbex, another supplier, said his company was looking to donate two million expired but still effective tablets to Japan.
Japan has distributed iodine tablets to evacuation centers near the nuclear plants that are leaking radiation.
Potassium iodide, also known by the chemical symbol KI, is used to saturate the thyroid gland with iodine so that radioactive iodine inhaled or ingested will not be retained by the gland.
For Americans trying to buy the pills, some experts say there is no need for them — and certainly no reason to use them now — because Americans are not being exposed to dangerous levels of radiation from the Japanese plants, nor are they likely to be.
“There’s a huge body of water between us and Japan,” said Kathryn A. Higley, head of nuclear engineering and radiation health physics at Oregon State University. “I have two kids. I’m not concerned for my kids one iota.”
Still, the situation in Japan could rekindle calls for the United States government to provide potassium iodide tablets to more people who live near American nuclear power plants.
The suppliers of the three versions of potassium iodide approved by the Food and Drug Administration, none of which require a prescription, said they were struggling to keep up with demand.
“We’re completely out,” said Mr. Morris, of Anbex, which sells the Iosat tablets through its Web site. Mr. Morris said the company could make millions of tablets a day after it geared up and that it hoped to have more supply by early April.
Recipharm has already stopped taking orders through its Web site for its ThyroSafe tablets.
Fleming Pharmaceuticals, which makes the ThyroShield liquid formulation suitable for young children, said it was shipping its product as fast as it could and was making more.
Few drugstores carry potassium iodide because there is usually no demand. Still, many drugstores, particularly on the West Coast, said they were besieged by requests.
“By the end of the day people were walking in and paying in advance,” said Whimsy Anderson, the naturopathic doctor at the Pharmaca Integrative Pharmacy in Los Angeles. The store quickly sold out the potassium iodide it had ordered from a dietary supplement company and then ran out of kelp capsules, which also contain iodine.
Dr. Gregory Brent, president of the American Thyroid Association and a professor of medicine at the University of California, Los Angeles, said other forms of iodine might also protect the thyroid gland, provided the amounts were large enough. The recommended dose of potassium iodide for adults is 130 milligrams a day. By contrast, Americans typically get only about one thousandth of that amount from food, he said.
Dr. Brent said that in rare cases, KI pills can cause hyperthyroidism or allergic reactions.
Congress passed legislation in 2002 requiring the federal government to supply potassium iodide capsules to people living within 20 miles of nuclear power plants in the United States.
But the administrations of George W. Bush and Barack Obama have not implemented that provision, saying the law allows for alternatives.
Some states have given pills to people living within 10 miles of nuclear plants, or stockpiled the pills for those people.
Representative Edward J. Markey, the Massachusetts Democrat who is the author of the 2002 legislation, said the crisis in Japan showed that the pills must be distributed beyond 10 miles from nuclear plants.
“We should not wait for a catastrophic accident at or a terrorist attack on a nuclear reactor in this country to occur to implement this common-sense emergency preparedness measure,” he wrote in a letter Monday to John Holdren, the White House science adviser.
The Department of Health and Human Services said in a statement that it would try to learn as much as possible from the Japanese crisis and response. “Policy options relating to KI distribution will be among the issues studied,” it said.
