LONDON -- The World Health Organization said Friday that Tamiflu should be given only to particularly vulnerable people, a warning to countries such as Britain where the swine flu drug is handed out freely.
WHO previously said it was up to doctors to decide who should get Tamiflu. On Friday, the U.N. agency said healthy people who catch mild to moderate cases of swine flu don't need the drug, but the young, old, pregnant, and those with underlying health problems do.
If countries use Tamiflu too liberally, that could lead to resistant viruses, leaving the world with few resources to fight swine flu.
WHO said people thought to be at risk for complications from swine flu -- children younger than 5 years old, pregnant women, people over age 65 and those with such health problems as heart disease, HIV or diabetes -- should get the drug.
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The agency recommended all patients, including children, who have severe cases of swine flu, with breathing difficulties, chest pain or severe weakness, should get Tamiflu immediately, perhaps in higher doses than now used.
"The WHO guidance is quite different from what has been done in England," said Hugh Pennington, a flu expert at the University of Aberdeen. "England's approach is out of step with the rest of the world on this."
In Britain, the government's response to the swine flu outbreak has come under fire for allowing Tamiflu to be handed out by call center workers who have as little as three hours of training.
Since the British set up a national flu service in July to deal with the surge of swine flu cases, Tamiflu has been available to anyone suspected of having the disease.
At its summer peak, British authorities guessed there were about 110,000 new cases of swine flu, also known as H1N1, every week. The number of new cases dropped last week to about 11,000, but the fall/winter flu season has not begun.
Boasting that Britain had the world's largest supply of Tamiflu, enough to cover 80 percent of its nearly 61 million people, Health Minister Andy Burnham promised the drug would be available to anyone who needed it.
Britons who call the national flu line can get Tamiflu without ever seeing a doctor. It is given out by call center workers who have no medical training. The operators' training lasts from three hours to a day. There are no health workers present at the call centers. Scotland, Northern Ireland and Wales decided not to participate in the swine flu phone line.
On its swine flu Web site, the Department of Health says "the government has decided to offer the antivirals Tamiflu or Relenza to everyone confirmed with swine flu."
To stop people fraudulently getting Tamiflu, the Web site says "the government is relying on the public to use the system responsibly." In its first two weeks of operation, the call center workers handed out more than 511,000 courses of Tamiflu.
The U.S. Centers for Disease Control and Prevention says antivirals must be prescribed by a health care professional. Canada's Public Health Agency does not recommend Tamiflu for people with mild illness.