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Flu Pill Serves as Short-Term Arsenal

Prevention: While the antiviral drug Tamiflu is not a substitute for immunization, it'll do--in a vaccine pinch, for instance.

November 27, 2000|BENEDICT CAREY | TIMES HEALTH WRITER

More heartless than any Grinch, this year's flu threatens to steal holiday cheer from thousands of homes. Doctors say the virus itself hasn't yet arrived in force in Southern California--but neither has the flu vaccine, at many local clinics, because of production delays that have caused shortages nationwide.

That's why an announcement last week by the Food and Drug Administration was so tantalizing. On Nov. 20, the agency approved an antiviral drug called Tamiflu for prevention of influenza in adults and adolescents. But in the next breath the agency declared: "Patients should continue receiving an annual flu vaccination. . . . Tamiflu is not a substitute for the flu vaccine."

So how exactly can the drug be useful?

Mainly as a short-term therapy, say doctors. "We've been told we'll have more flu vaccine shortly," says Thomas Horowitz, co-chairman of family and emergency medicine at Good Samaritan Hospital in Los Angeles. "For some people, we may be able to use Tamiflu to buy some time, a week or so, while we wait."

Because of vaccine production delays, federal and local health officials have been urging clinics to ration the shots, treating first those people who are most threatened by the disease, such as the frail and elderly. The flu season doesn't usually peak until late December or January, they say, and more vaccine is expected to arrive over the next few weeks.

In the meantime, Tamiflu is widely available and covered in some health plans--for the treatment of flu symptoms, for which it was approved last year, says Charles Alfaro, a spokesman for Hoffman-LaRoche Inc., maker of Tamiflu. At $49 wholesale for a packet of 10 pills, it's not clear yet whether plans will cover the drug for this newly approved use--flu prevention.

Nonetheless, Horowitz says, those who have quick access to a doctor and a pharmacy may be able to get a 10-pill "treatment" supply and use it for emergency prevention, in case the flu hits and vaccine is still in short supply. The prevention dose is one pill a day.

Unlike a flu shot, which can take a week to kick in, Tamiflu works immediately. It interferes with a protein found on the surface of most strains of flu virus and leaves the invader unable to infect other cells. The body is spared the miserable coughing, aches, exhaustion and fever that set influenza apart from the common cold. Those symptoms are life-threatening in many frail, elderly or chronically ill people, especially those with lung or heart conditions. On average, about 20,000 people a year die of the flu in this country.

Dr. John Treanor, an infectious disease specialist at the University of Rochester in New York, who has studied Tamiflu, says it could be helpful for "the guy who comes in, gets a vaccine and the doctor is worried that the vaccine might not take effect for another week or so. You could take Tamiflu for that first week."

In one study cited by the FDA, involving some 950 people in households in which a family member had the flu, just 1% of those taking the drug got sick, compared with 12% taking a dummy pill. And Tamiflu worked even when taken up to 48 hours after exposure. This two-day window, combined with its quick action, should make Tamiflu useful as a supplemental therapy in nursing homes, retirement centers and other small, confined communities where the flu can be devastating, doctors say.

"Influenza vaccines are by far the most important tool for preventing illness," says Dr. Keiji Fukuda, chief of epidemiology at the influenza branch of the Centers for Disease Control in Atlanta. "They're inexpensive, you get just one, and you're done. But some people, many of them elderly, don't respond well to the vaccine and may still get sick. So clearly there are situations, in nursing homes for example, where we would use antiviral drugs to control an outbreak among vaccinated populations."

Horowitz says the drug also could limit outbreaks in unvaccinated people: in office buildings, for example, or medical clinics, where workers are continually exposed. Anywhere people work in close quarters, for that matter, a flu outbreak can hit particularly hard; and it might pay an employer to protect workers rather than lose work days, doctors suspect.

"It could get you through that week or two weeks when everyone's getting sick," Horowitz says. "Or if you're traveling on an airplane, going to a meeting, it might give you a little more protection. Some people have a kind of superstition about the air on planes, and this could reassure them."

In two other studies cited by the FDA--involving 1,480 people taking the drug for six weeks during peak flu season--only about 1% of those taking the drug got sick, compared with some 4% taking dummy pills. According to Hoffman-LaRoche's Alfaro, that amounts to a nearly airtight insurance against infection.

Nonetheless, doctors are skeptical that many people will use Tamiflu in this way. For one thing, says Fukuda, a flu season may last eight weeks or more. And then there's the cost. A six-week supply for prevention could cost hundreds of dollars, and it's not yet clear if health plans will pay for that.

Furthermore, health officials say that infection rates in an average flu season are lower than many of us assume: typically between 5% and 10%. "Most of us are not going to get the flu," says Horowitz. "So you would have to have real paranoia or an excess of income to be taking the drug for the entire season."

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