Flu drug sales soar; specialists fear overuse

Amid surging fears that avian influenza could ignite a global epidemic, sales of the flu medication Tamiflu are soaring in the United States, with prescriptions for the drug running as much as eight times higher than last year.

Alarmed infectious disease specialists said excessive use of Tamiflu and other antiviral drugs could lead to the emergence of flu strains that do not respond to antivirals, making both avian and regular flu strains even more of a health threat. They also said they have seen evidence that patients and doctors are stockpiling the drug on their own, which could create a shortage for people actually stricken with the flu, especially if there is a global epidemic.

''In case we need to make use of this drug, it's going to be hard to distribute it appropriately," said Dr. Deborah Yokoe, a top disease tracker at Brigham and Women's Hospital.

Until recent years, there was little doctors could offer flu patients beyond a recommendation to take aspirin, drink fluids, and rest. But Tamiflu, which came on the market six years ago, can cut patients' suffering by a few days -- if they take the drug soon after the onset of symptoms. It has proven more effective against the ordinary flu than three other antiviral medications, and specialists are hopeful that it could reduce deaths should there be an avian flu outbreak.

There is no vaccine against avian flu, although scientists are trying to develop one, and in recent weeks, Tamiflu has sold better than ever.

''Sales are definitely off the chart," Greg French, a spokesman for Drugstore.com, said yesterday in a telephone interview from the Internet company's headquarters in Bellevue, Wash. ''Over the past five weeks or so, we've actually sold more product than we did in the last six months of last year." The drug is now among the company's top five sellers.

A firm that monitors trends in the pharmaceutical industry, Verispan, reports that US physicians last week wrote about 34,000 prescriptions for Tamiflu, eight times more than a year earlier.

The typical prescription for Tamiflu, made by the Swiss drug company Roche Holding AG, is two 75-milligram pills a day for five days. A 10-pill bottle was being offered yesterday on Drugstore.com's website for $65.99.

Manufacturers are gearing up to meet the rising demand for Tamiflu. In an e-mailed response to questions about Tamiflu, Roche spokesman Terence Hurley said the pharmaceutical company doubled its capacity to make Tamiflu in 2004 and doubled it again this year. An Indian pharmaceutical company, Cipla Ltd., said yesterday it intends to bring a generic version of Tamiflu to the market. But generic makers cannot legally sell patented drugs in the West, and Roche has said it would not license generic versions of the drug.

The World Health Organization has encouraged governments to create antiviral stockpiles, and, last month, the US Senate approved spending $3.9 billion to expand the country's reserve. The federal government wants enough Tamiflu to treat 20 million Americans, but Roche has said it will take years to produce that much.

But the recommendation to stockpile antivirals was never intended to extend to the medicine cabinets of patients, said Dave Daigle, a spokesman for the US Centers for Disease Control and Prevention, adding that the traditional recommendations for preventing the spread of flu virus would apply to avian flu.

''We've been telling people, 'Listen to what your Mom tells you to do during flu season instead of stockpiling Tamiflu: Wash your hands, avoid close contact with people who are sick, cover your mouth when you cough or sneeze,' " Daigle said.

Despite those admonitions, reports this week that birds carried a virulent strain of avian flu as far west as Turkey have intensified pleas from patients for Tamiflu prescriptions, doctors said.

''I think it's definitely because of the avian flu," said Dr. Richard Marshall, chief medical officer of Harvard Vanguard Medical Associates.

Since 2003, 117 humans have contracted avian flu, resulting in 60 deaths. The human cases have been confined to four Asian nations, and there is no evidence so far that the virus is easily transmitted person to person. Almost all the human cases have been linked to prolonged contact with birds, with many traced to poultry slaughterhouses. But flu viruses mutate quickly, and some disease specialists say they believe that avian flu has the potential to spark a worldwide human epidemic, particularly if the avian strain combines with another flu strain that has the capacity to easily spread person to person. Doctors said there is no way of knowing how effective Tamiflu would be against such an epidemic strain.

A report released yesterday by the journal Nature showed that a Vietnamese teenager had been infected with a bird flu strain that was resistant to Tamiflu. Specialists fear that such resistant strains could become widespread if people start taking Tamiflu recklessly. If patients fail to take the full course of a drug, it allows the hardiest strains to survive -- and to mutate and become unresponsive to the drug.

''If you take them inappropriately, I can guarantee you they will become ineffective in a short period of time," said Dr. Alfred DeMaria, director of communicable disease control in Massachusetts.

Dr. Roy Welker, director of travel medicine at Brigham and Women's, recently received a call from a businessman traveling to India, where there have been no human cases of avian flu. The man had received inoculations against endemic illnesses in South Asia.

''He said everyone in his party that's going on this business trip to India had gotten Tamiflu from their doctors, and he wanted it, too," Welker said.

The infectious disease specialist said he attempted to dissuade the man from his desire to get Tamiflu, telling him there was no evidence avian flu posed any human threat in India, especially to a businessman planning to stay in a hotel. ''I don't know what the guy decided to do," Welker said.

Stephen Smith can be reached at stsmith@globe.com.