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US: new questions about safety of anti-inflammatory drugs
By Joseph Kay
24 December 2004
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Last week, the drug company Pfizer announced that it had found
evidence of a connection between Celebrex, an anti-inflammatory
drug that it manufactures, and an increased risk of heart attacks
and strokes. The announcement calls into question the safety of
a whole class of drugs commonly used to treat arthritis in millions
of people in the US and internationally.
In late September, the drug company Merck withdrew its blockbuster
drug Vioxx from the market after discovering a similar tendency
to increase serious heart conditions. Both Vioxx and Celebrex
are part of the class of anti-inflammatory drugs known as COX-2
inhibitors. They had been massively promoted and advertised during
the past five years before problems with the drugs were publicized.
While Pfizer has said it is not withdrawing Celebrex, it has
ceased all direct-to-consumer advertising. An eventual complete
withdrawal of the drug appears likely. Some scientists have also
raised concerns about another COX-2 inhibitor manufactured by
Pfizer known as Bextra.
The National Cancer Institute sponsored the study that produced
the results on Celebrex. It was part of an attempt by Pfizer to
demonstrate a beneficial effect of Celebrex in preventing certain
types of cancer. However, during the study researchers discovered
that patients taking high doses of Celebrex were 2.4 times more
likely to develop heart disease than patients on placebo.
Pfizer has stated that other studies do not find a connection
between Celebrex and heart disease, and that the drug is just
as safe as other anti-inflammatories. Nevertheless, the US Food
and Drug Administration (FDA) issued a statement on Friday urging
patients on Celebrex to seek an alternative therapy
and left the door open to forcing a withdrawal of the drug.
On Monday, the FDA issued a warning on another drug used to
treat inflammation, naproxen. Naproxen is most commonly manufactured
by the German company Bayer under the brand name Aleve. Preliminary
findings in a study carried out by the National Institute on Aging
suggest that patients over the age of 70 are 1.5 times more likely
to develop a serious heart condition than patients on placebo.
In the study, no noticeable increase was evident in patients taking
Celebrex, i.e., the heart problems associated with the drug found
in the National Cancer Institute study were not repeated in the
National Institute on Aging study.
The lead investigator in the study, John Breitner of the Veterans
Administration Puget Sound Health Care System, cautioned that
the findings were only a weak signal of potential
problems with naproxen. He pointed out that the data, which has
yet to be fully analyzed or vetted by other scientists, was not
necessarily even statistically significant, meaning that the increased
risk may be merely a result of chance rather than an effect of
the drug.
Naproxen is not a COX-2 inhibitor, and scientists had long
believed that it actually helped reduce the chance of heart attacks
and strokes. Dr. Garret FitzGerald, chairman of the University
Of Pennsylvanias pharmacology department, stated, Its
much too early from the information provided to know if this is
a meaningful result or not.
At the same time, Breitner noted that the problems found in
Vioxx and Celebrex may be general to a broader class of anti-inflammatory
drugs. It may be a problem for all nonsteroidal anti-inflammatory
drugs [including COX-2 and naproxen], because weve never
had an opportunity to examine this question, he said.
Given the very preliminary character of the results on naproxen,
why were they heavily promoted on Monday? The FDA went so far
as to issue a statement urging patients to limit use of the drug
and hinted at possible future regulatory action. The story was
the main item in many of the evening news programs in the US on
Monday.
The concerns raised about naproxen do have the effect of relieving
pressure on both the drug companies and the FDA for the scandal
involving COX-2 inhibitors. In its article on Tuesday, the
New York Times noted that the results on naproxen could
prove beneficial for Pfizer, which has been arguing that last
weeks findings about Celebrex should be placed in the context
that similar pills may be just as hurtful to the heart and that
other studies of Celebrex have shown no such worries. Indeed,
if there is one message from these studies it is that nothing
is certain in this science.
The paper quoted Sandra Kweder, deputy director of the FDAs
Office of New Drugs, as stating, This is a very confusing
situation. Every doctor and patient is going to have to have a
conversation about their unique risks. The Office of New
Drugs is the branch of the FDA that is most closely tied to the
interests of the pharmaceutical industry. Her comments were echoed
by Pfizers Chairman and CEO Hank McKinnell, who stated that
physicians and patients are understandably confused
at the different results of the studies.
However, while the exact side effects of the different drugs
may be unclear, there is nothing confusing about the history of
COX-2 inhibitors. Many scientists have warned of potential problems
with this class of drug for years, without provoking any response
from the FDA to seriously investigate potential health problems.
Evidence indicates that the drug companies, particularly Merck,
worked assiduously to cover up damaging results in order to keep
sales at extraordinarily high levels. [See The Vioxx recall:
cover-up of health risks may have resulted in thousands of deaths
http://www.wsws.org/articles/2004/nov2004/viox-n10.shtml]
COX-2 inhibitors were originally developed as a class of drugs
that would treat arthritis and inflammation without causing gastrointestinal
bleeding, a side effect some patients experience with the use
of other anti-inflammatory drugs, including ibuprofen and naproxen.
They are supposed to work by blocking one enzyme, COX-2, that
is thought to cause inflammation, without blocking another enzyme,
COX-1, thought to protect the stomach lining.
However, the number of patients that suffer serious side effects
from the use of the other drugs is fairly small, numbering in
the tens of thousands. The drug companies wanted toand didturn
the drugs into blockbusters, used by tens of millions of people
around the world.
An article in the New York Times on December 19 by Barry
Meier (Medicine Fueled by Marketing Intensified Trouble
for Pain Pills) notes, Having spent hundreds of millions
of dollars to develop their drugs, the makers of Celebrex and
Vioxx, cheered on by Wall Street, had every motivation to expand
their markets beyond the older people most at risk of ulcers to
encourage the drugs use by millions more people of all ages.
The advertising campaigndirected both at patients and
doctorsobscured the fact that the medications were not proven
to be any more effective in relieving pain than traditional medications
such as ibuprofen. Pfizer has never been able to even conclusively
demonstrate that Celebrex reduces the risk of stomach problems
as compared to ibuprofen.
As Meier reports, Since the drugs release, the
companies have spent hundreds of millions of dollars on television,
newspaper and magazine advertising for them and, by some estimates,
at least as much on marketing and promoting the drugs to doctors.
As a result, many medical experts now say that Celebrex and Vioxx,
selling for $2 or $3 a pill, have been too widely prescribed to
patients who could safely obtain the same pain benefits from over-the-counter
drugs costing pennies apiece.
According to the research firm TNS Media Intelligence/CMR,
Pfizer spent over $71 million to advertise Celebrex during the
first nine months of 2004, up 55 percent from the level of advertising
purchased during the same period last year. Consumers have been
bombarded with commercials urging them to celebrate
with Celebrex, and doctors have been heavily courted encourage
them to prescribe the drug.
As a result of this advertisement, Meier notes, Within
little more than a year, the drugs had grabbed about 40 percent
of the market from traditional anti-inflammatory drugs like ibuprofen.
The two drugsVioxx and Celebrexbecame critical
for their respective producers. Pfizer estimates that since the
FDA approved Celebrex in 1998, it has been prescribed to 27 million
Americans. It has generated over $3 billion in sales for the company
in 2004, and some estimates predicted sales to soar to as much
as $9 billion in 2005, in part due to the withdrawal of Vioxx.
This would be 9 percent of the companys entire revenue.
The drug industry as a whole has faced a growing crisis during
the past five years, as many major drugs have reached their patent
limit, the point after which the drugs can legally be made as
generics and sold at much lower prices. Companies such as Pfizer
and Merck have become increasingly dependent upon the revenues
generated by a handful of drugs. They spend large portions of
their revenues on promoting these drugs and increasing sales as
much as possible.
While COX-2 inhibitors may have important uses for some patients,
their mass promotion was entirely unnecessary. Not only did purchasing
these drugs cost patients billions in medical expenses, tens of
thousands may have needlessly died due to the drugs harmful
side effects.
The success of the drugs was only possible with the help of
the FDA and the decline of regulation of the drug industry. The
explosion in drug advertising, particularly in direct-to-consumer
advertising, was only possible after regulatory changes implemented
during the late 1990s.
The FDAs Office of New Drugs (OND), which is responsible
for approving drugs for the market, has been greatly expanded
at the expense of the sections of the FDA responsible for monitoring
the safety of drugs already on the market. At the same time, the
OND has been made more dependent on the industry it is supposed
to regulate. Indeed, much of the offices funding comes directly
from the drug industry, in the form of fees intended to speed
up the drug approval process. Both Vioxx and Celebrex were approved
after expedited reviews, even though little was known about their
potential benefits and side effects.
Some FDA scientists have alleged that they were pressured to
bury findings that suggested problems with drugs already on the
market. One survey found that one-fifth of scientists at the FDA
said they felt pressure to approve a new drug despite concerns
about safety, effectiveness or quality.
David Graham, a scientist in the FDAs Office of Drug
Safety, has denounced the FDA for its failure to regulate Vioxx
and other drugs. He has charged that officials in the FDA sought
to suppress his own research indicating problems with the drug.
Since he came out with broad accusations, he says he has been
sidelined and threatened with a job change by officials in the
agency.
See Also:
The Vioxx recall: cover-up
of health risks may have resulted in thousands of deaths
[10 November 2004]
Medicine and the market: the
Vioxx and flu vaccine debacles
[8 October 2004]
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