|
First the painkiller
Vioxx; now the diabetes drug Avandia. Another big drug safety issue
has consumer groups, doctors and congressmen calling for an overhaul
of the U.S. Food and Drug Administration.
A medical
journal published an analysis suggesting that Avandia raised the
risk of heart attacks and possibly deaths. More than 6 million
people worldwide have taken the drug to control blood sugar since it
came on the market eight years ago, and about 1 million Americans
use it now.
Cases like this will
continue “until we are able to get a better system of drug approval
and surveillance,” said Dr. Jerry Avorn, a Harvard Medical School
professor and author who has criticized the FDA for not watching
more closely for problems with drugs it has approved.
The consumer group
Public Citizen said the FDA has failed to require Avandia’s maker to
adequately warn about the dangers of the drug. And Consumers Union
called on the agency to make results of all consumer drug testing
public “so doctors, researchers and patients can more quickly know
about a drug’s possible risks.”
Pooled results of
dozens of studies on nearly 28,000 people revealed a 43 percent
higher risk of heart attack for those taking Avandia compared to
people taking other diabetes drugs or no diabetes medication,
according to the analysis published online Monday by the New England
Journal of Medicine.
Particularly Hazardous Link
The findings are frightening because two-thirds of the
people with Type 2 diabetes, the most common form, die of heart
problems, so a drug that boosts this possibility is especially
hazardous for them.
Still, the actual
risks to any single patient appear small. Diabetics should talk to
their doctors before stopping any medication, said a statement
issued by the American Diabetes Association and two groups of heart
doctors.
Avandia’s maker,
British-based GlaxoSmithKline PLC, disputed the results of the
analysis but acknowledged that its own similar review found a 30
percent increased risk — information it gave last August and
possibly even earlier to the Food and Drug Administration. But the
company said that more rigorous studies did not confirm excess risk.
FDA officials issued
a safety alert on Monday and said they likely would convene an
advisory panel, but planned no immediate changes to the current side
effect warnings on the drug’s packaging.
Legislators Announce Hearing
Several members of Congress expressed alarm. Rep. Henry
Waxman, D-Calif., chairman of the House Committee on Oversight and
Government Reform, announced a hearing for June 6 on FDA’s role. On
the Senate floor, Charles Grassley, R-Iowa, criticized the agency
for not acting more swiftly.
“Do we have another
Vioxx on our hands with Avandia? I am not sure, but I intend to find
out,” he said, referring to the blockbuster arthritis drug withdrawn
in 2004 because of safety problems. “Tens of millions of
prescriptions have been written for Avandia, and Medicare and
Medicaid have paid hundreds of millions of dollars for this drug.”
Avandia is used to
treat Type 2 diabetes, which is linked to obesity and afflicts 18
million Americans and 200 million people worldwide. This form of
diabetes occurs when the body does not make enough insulin or cannot
effectively use what it manages to produce.
Avandia, or
rosiglitazone, helps sensitize the body to insulin and was
considered a breakthrough medication for blood-sugar control. It
also is combined with metformin and sold as Avandamet. Only one
other drug like it — pioglitazone, sold as Actos and Actoplus Met by
Takeda Pharmaceuticals — is sold in the United States.
Avandia had total
U.S. sales of $2.2 billion in 2006, slightly trailing $2.6 billion
for Actos, according to IMS Health, a healthcare information
company. About 13 million Avandia prescriptions were filled in the
U.S. last year. A one-month supply of Avandia sells for between $90
and $170.
Shadow
Cast on Potential Alzheimer's Therapy
GlaxoSmithKline also has been testing Avandia to try to
prevent diabetes in those at high risk of it, and, in separate
studies, to prevent Alzheimer’s disease.
However, the new
analysis casts a pall on its prospects for prevention as well as
treatment, many specialists said. The study was led by Dr. Steven
Nissen and statistician Kathy Wolski at the Cleveland Clinic. Nissen
accepts no personal fees for consulting for any drug makers.
While the analysis
doesn’t spell out the actual the rate of heart attacks among Avandia
users, the 43 percent excess risk is in line with what a similar
analysis found for lower doses of Vioxx use, Nissen said. Another
context for that number: Heart attack risks are lowered about 25
percent by cholesterol-reducing statin drugs — ample reason to
prescribe them.
The Avandia studies
Nissen analyzed were not designed to look for heart risks and many
of them were so short — some only 24 weeks — that risks may only
appear over the longer term, he said.
Dr. David Nathan,
chief of diabetes care at Massachusetts General Hospital, agreed.
“This analysis is
just scratching the surface of what may be there. It needs to be
taken seriously,” said Nathan, who reviewed the paper for the
medical journal and has no financial ties to any diabetes drugmakers.
The situation
“reflects very badly on the FDA and on Glaxo,” Nathan said. “It’s
the FDA’s responsibility to be monitoring this stuff.”
The drug “represents
a major failure of the drug-use and drug-approval processes in the
United States,” Drs. Bruce Psaty and Curt Furberg wrote in an
editorial in the New England Journal. Psaty is with the University
of Washington in Seattle and Furberg is with Wake Forest University.
When the drug was
approved, evidence of its benefits were “at best mixed,” wrote the
two doctors. Both have been frequent critics of the FDA’s failure to
spot dangers in the drug approval process and its conduct involving
Vioxx.
Avandia’s label
already warns about possible heart failure and other heart problems
when taken with insulin. The drug also raises LDL or bad
cholesterol, and can cause fluid retention and weight gain. Glaxo
also has reported some patients suffered more bone fractures,
swelling of the legs and feet, and rare reports of swelling in the
eye that can cause vision problems.
However, in a
conference call, Dr. Lawson McCartney who leads Glaxo’s
diabetes drug development, said: “We remain very confident in the
safety and of course in the efficacy of Avandia as an important
diabetic medicine.”
FDA says
risks not clear-cut
Dr. Robert J. Meyer of the FDA’s Center for Drug
Evaluation and Research, also defended the agency’s actions, saying
information about risks is not clear-cut.
“We’ve tried to
weigh the risks of going forward with an uncertain message ... with
the level of uncertainty about the safety signal before us.”
Copyright © 2006-2010.
www.diabetesdiabeticdiet.com. All Right Reserved.
All trademarks, registered
trademarks, product names and company names or logos mentioned herein are the
property of their respective owners.
Disclaimer:
www.diabetesdiabeticdiet.com
does not endorse the use, or effectiveness of any diets. This site is
designed to provide information, not medical advice.
|
