Vioxx News
NEW YORK - Patients taking the Vioxx arthritis drug had a
50 percent greater chance of heart attacks and sudden cardiac death than individuals
using Pfizer Inc.'s rival Celebrex medicine, according to a large study financed
by the U.S. Food and Drug Administration.
Kaiser Permanente, which is one of the biggest U.S. health-maintenance organizations
and has more than 8 million members, is reconsidering its use of Vioxx following
the study, the Wall Street Journal said on Thursday.
Physician committees from Kaiser will decide how to address the findings, which
were based on data from its patients, in the next few weeks, the newspaper said.
A call to Kaiser was not immediately returned.
The study, presented at an epidemiologists conference in Bordeaux, France on
Wednesday, is the latest to suggest that the drug increases the danger of heart
attacks. Lingering safety concerns have badly hurt sales of Vioxx in recent
years.
The study also found patients taking the highest recommended daily dosage of
Vioxx had three times the risk of heart attack and sudden cardiac death as those
not taking standard painkillers.
Sudden cardiac death, an electrical disturbance of the heart that is not considered
a heart attack, is the biggest cause of death in the United States.
Three-fold risk increase
Researchers came up with the potentially damaging findings on Vioxx after analyzing
the medical records of 1.4 million people insured by Oakland, California-based
Kaiser.
The study found 8,199 heart attacks and cases of sudden cardiac death among
the Kaiser members between 1999 and 2001.
Dr. David Graham, lead investigator for the trial, said another major finding
was that patients taking the typical starting dose of Vioxx had a 50 percent
greater chance of heart attack and sudden cardiac death than patients taking
any dose of Celebrex.
Based upon the evidence in this study, I don't think doctors should prescribe
high-dosage Vioxx, and patients shouldn't take it, Graham said in an interview.
Asked if the FDA might consider banning use of high-dose Vioxx, given the findings,
Graham said, The FDA has to decide whether they think a three-fold increase
in heart attacks outweighs the benefits of the drug.
Alise Reicin, vice president of clinical research at Merck, said the study
was merely "observational", and not the preferred formal kind of study
in which patients are enrolled and then randomly placed into different treatment
groups.
Observational studies have inherent limitations, she said, and often produce
inaccurate results.
Most patients take daily Vioxx doses of 12.5 milligrams and 25 milligrams for
arthritis. But a higher dose of 50 milligrams is approved by the FDA for treatment
of pain for no longer than five days.
The problem is that some patients continue to take it for 30, 60, or 90 days,
Graham said, putting themselves at elevated risk of heart attack and sudden
cardiac death.
Graham, senior scientist for the FDA's Office of Drug Safety, said his own
interpretations of the data did not necessarily reflect the views of the FDA.
Comparison unfair
In Merck's own 8,000 patient trial of Vioxx before the drug was launched in
1999, over twice as many arthritis patients taking it had heart attacks and
strokes than those who took Naproxen -- one of the most popular older arthritis
treatments.
Merck has argued that Vioxx itself did not cause the heart attacks but that
Naproxen was somehow preventing them -- putting Vioxx in an unfair bad light
in the head-to-head trials.
But Graham said his trial suggested that naproxen actually slightly increases
the risk of heart attacks, casting doubt on Merck's theory.
Reicin said a group of smaller Merck trials have not shown any greater risk
of heart attack for Vioxx than Celebrex.
Although Merck has steadfastly defended the safety of Vioxx, its sales have
flattened in recent years amid the lingering safety concerns and cardiovascular
risks cited by independent researchers.
That has allowed Celebrex and a sister Pfizer drug, called Bextra, to dominate
the market for their class of arthritis drugs, called Cox-2 inhibitors.
The newer drugs are designed to fight inflammation and pain while reducing
the risk of ulcers caused by traditional non-steroidal anti-inflammatory drugs
(NSAIDs), such as aspirin, naproxen and ibuprofen.
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