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Dec
11, 2010: Update
FDA
OKs Pfizer Anti-Smoking Pill!
WASHINGTON
(AP) -- A tablet shown to help more than one in five smokers
quit joined the limited number of effective stop-smoking drugs
on Thursday, approved by federal regulators.
When
varenicline goes on sale later this year, it will become the
first new prescription drug for smoking cessation approved
by the Food and Drug Administration in nearly a decade and
only the second stop-smoking drug that is nicotine-free, according
to Pfizer Inc.
The
New York company plans to market the twice-daily tablet, intended
for adults only, as Chantix.
"It's
a welcome new addition. It's like with cancer or heart disease
or high blood pressure or diabetes: The more effective treatments
you have, the better off patients are," said Dr. Steven
Schroeder, a professor of medicine at the University of California,
San Francisco, who is active in smoking cessation efforts.
Varenicline
works in two ways, by cutting the pleasure of smoking and
reducing the withdrawal symptoms that lead smokers to light
up over and over again.
Most
other stop-smoking drugs are various nicotine-replacement
therapies, sold by prescription and over the counter in gum,
patch, lozenge, nasal spray or inhaler form. In 1997, the
FDA approved bupropion, an antidepressant already sold as
Wellbutrin but then rebranded as Zyban, an anti-smoking drug.
Several
studies conducted in Europe on about 2,000 smokers and presented
in November at an American Heart Association conference showed
that a year after initial treatment with varenicline, abstinence
rates were 22 percent, versus 16 percent among those given
Zyban. Just 8 percent of those given dummy medicines had stopped
after a year.
The
approved course of Chantix treatment is 12 weeks, a period
that can be doubled in patients who successfully quit to increase
the likelihood they will remain smoke-free, the FDA said.
Other
clinical trials have shown that the drug's effect is more
pronounced in the short-term: 44 percent of longtime, pack-a-day
smokers quit following a 12-week course of treatment with
Chantix, compared with the 30 percent of Zyban patients who
quit, according to Pfizer. However, smoking cessation experts
said the longer-term data are more applicable, given the difficulty
of quitting the habit for good. Even Pfizer acknowledged it
can take smokers 10 attempts.
"It's
not going to be a revolution, it's going to be a substantial
step forward," Thomas Glynn, director of cancer science
and trends at the American Cancer Society, said of varenicline.
Glynn added that the greatest value will be for smokers who
have tried Zyban or nicotine-replacement therapy but failed
to quit.
"My
bet is that it will work as well as they do and, from the
look of things, a little bit better," he said. The FDA
does not recommend that Chantix be used with any other stop-smoking
drug.
Varenicline
latches on to the same receptors in the brain that nicotine
binds to when inhaled in cigarette smoke, an action that leads
to the release of dopamine in the pleasure centers of the
brain. Taking the drug blocks any inhaled nicotine from reinforcing
that effect. Its most common side effect is nausea.
The
drug also slows the release of dopamine, thereby cutting the
craving to smoke that occurs when nicotine's effect wears
off, said Pfizer research chemist Jothan Coe, who invented
the drug.
"It's
a shield and at the same time, it stabilizes you and prevents
you from having the lows, which lead to craving and withdrawal,
but at the same time, it shields you from the highs,"
said Coe, a former 2 1/2 pack-a-day smoker who quit smoking
the first time cold turkey and then a second time with the
help of nicotine gum.
One
in five American adults, or nearly 45 million people, smoke.
An estimated 32 million of those smokers would like to quit,
according to the Centers for Disease Control and Prevention.
Smoking kills nearly 440,000 Americans a year.
"Tobacco
use, particularly cigarette smoking, is the single most preventable
cause of death in the United States and is responsible for
a growing list of cancers, as well as chronic diseases including
those of the lung and heart," said Dr. Scott Gottlieb,
the FDA's Deputy Commissioner for Medical and Scientific Affairs.
Fewer
than one in 20 smokers can quit without help, said Schroeder
of UC San Francisco. Even with help, whether it's a drug,
counseling or both, the success rate rises at most to roughly
one in five, he added.
Both
the FDA and European regulators recently rejected applications
by Sanofi-Aventis to gain approval for rimonabant, or Accomplia,
as a stop-smoking aid. Both have recommended that the drug,
which blocks the same pleasure centers in the body activated
when pot smokers get the munchies, be approved for weight
loss.
And
at least two vaccines are being developed that could block
nicotine from ever reaching the brain.
Pfizer
wouldn't say what Chantix will cost. The company had predicted
annual sales of $1 billion, but analyst Barbara Ryan at Deutsche
Bank is predicting $500 million in annual sales by 2009.
Associated
Press business writer Theresa Agovino in New York contributed
to this report.
Varenicline
looks to have some potential!!
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