Flu Drugs Hit the Major League
For prevention, the flu shot is still doctors'
first pick -- but Tamiflu and Relenza come in second
By Leah Shafer
s we enter the flu
season again, it's a good time to take stock of two antiviral
drugs that were released in 1999 to fight the influenza virus,
better known as the flu. Nearly 1 million Americans rushed to
the doctor last winter for zanamivir (Relenza) and oseltamivir
phosphate (Tamiflu), new antiviral drugs approved by the Food
and Drug Administration (FDA) in 1999. In clinical studies, if
started within two days after symptoms appear, these medications
were shown to be moderately effective in increasing the rate of
This winter, doctors should expect even more patients to request
the two antiviral therapies, because in addition to treating the
flu, Tamiflu has been approved by the FDA to prevent people from
getting the nasty bug in the first place. Relenza is under review
by FDA for the same thing.
Given the serious delays and shortages of flu vaccine in 2000,
and health officials' recommendation that healthy people delay
getting their shot until high-risk groups are vaccinated, Tamiflu
and Relenza may get their chance to be all-stars in this season's
An ounce of prevention
In recent studies, both Relenza and Tamiflu showed dramatic results
in preventing the spread of the flu virus. Tamiflu, a pill marketed
by Hoffmann-LaRoche, reduced the risk of catching the flu by up
to 92 percent. In a study by the University of Virginia Medical
Center, Glaxo Wellcome's inhalant Relenza was 79 percent effective.
Tamiflu and Relenza are not meant to replace the flu
vaccine, but when an immediate member of the family
gets ill, or for certain high-risk groups, these medications
might be well worth the money.
But when you look at the difference in cost between the flu shot
and these medications, they lose some of their appeal. A 10-day
supply of Tamiflu costs $49 wholesale; five days of Relenza is
$48. An entire season of either could run into the hundreds of
In contrast, flu shots are often covered through insurance or
Medicare or are available low-cost at public health clinics.
These antiviral medications are not meant to replace the flu
vaccine, but when an immediate member of the family gets ill --
or for certain high-risk groups, such as the elderly or immune-compromised
-- these medications might be well worth the money.
The flu shot: good as gold
The number of people who took advantage of these new medications
falls far short of the 75 million Americans who tried to prevent
infection by getting the flu shot instead. With a 70 to 90 percent
effectiveness rating, the influenza vaccination remains the primary
means to prevent and control the spread of the virus and, as such,
is the true MVP of the flu season.
Officials at the Centers for Disease Control and Prevention (CDC)
agree that the flu vaccination is the preferred choice. In a December
1999 report, the agency's doctors commented that "antiviral agents
are an adjunct ... not a substitute for the vaccine."
Flu Shot Shortage
This year, health care providers around the United
States are experiencing delays and shortages of the
flu shot due to manufacturing problems. This has meant
that many healthy people wanting to be vaccinated
have been turned away or told to wait.
But relief is in sight. Manufacturers have shipped
about two-thirds of the influenza virus vaccine this
year. The remaining one-third will be available in
December 2000, according to the U.S. Centers for Disease
Control and Preventon. (CDC).
Even with the remaining vaccine, there will be reductions
of available vaccine for the 2000-2001 flu season.
In response, the CDC has asked Aventis-Pasteur, Inc.,
to manufacture an additional 9 million influenza vaccine
Ideally, the public would have been vaccinated from
October through mid-November, but because of the shortages,
the vaccine should be offered through January. Check
with your health care provider if you have not been
vaccinated yet this season.
The vaccine allows people to be proactive about their health
and not wait for the misery of flu to knock them flat.
"From a public health perspective, the ideal would be for at-risk
folks to get vaccinated [for the flu] and not wait until they
get it," says Heidi Jolson, M.D., director of the Division of
Antiviral Products at the FDA.
Bacteria or virus? A tough call
Many medical experts would like patients to keep the flu shot
as their primary defense not only because it is cheaper and very
effective, but because it's easy for doctors to confuse viral
and bacterial infections. Since both Relenza and Tamiflu must
be started within two days of symptom onset, many people who felt
the flu coming on rushed to the emergency room or to their physician
to get the new medications. Unfortunately, with the pressing need
to make an early diagnosis, several patients who didn't, in fact,
have the flu were given these antiviral medications, only to see
their symptoms remain unchanged or worsen.
In mid-January 2000, the FDA issued a public advisory in a memo
to health care professionals cautioning them against being too
heavy-handed in prescribing the new flu drugs. In it, Murray Lumpkin,
M.D., the deputy director of the Center for Drug Evaluation at
the FDA, noted several cases in which patients with influenza-like
symptoms actually had severe bacterial infections that worsened
during antiviral therapy.
Dr. Lumpkin also advised physicians to be cautious in prescribing
Relenza for patients with underlying asthma or chronic obstructive
pulmonary disease. Relenza is known to cause respiratory problems
in some of those patients.
At the time Relenza and Tamiflu were introduced last fall, there
was tremendous media attention given to the coming flu season
and to the prospect of drugs that could fight off its worst effects,
Dr. Jolson said. Last winter, Glaxo Wellcome, maker of Relenza,
and Hoffman-LaRoche, maker of Tamiflu, targeted cities hardest
hit with influenza with heavy advertising ranging from full-page
newspaper ads to television commercials. The resulting public
clamor for these flu drugs prompted the FDA advisory last January.
"We thought we'd remind doctors and patients that symptoms of
bacterial infections can be similar to those of the flu, and that
patients with the flu may also have a bacterial infection," Dr.
Relenza and Tamiflu will surely step up to the plate many times
during the next flu season, both for prevention and cure, but
the flu vaccination remains the heavy hitter against the virus.
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