Vioxx's closest competitors -- Bextra and Celebrex -- were also closely scrutinized in the wake of heightened cardiovascular risks associated with the drugs. Bextra was withdrawn from the market in 2005 and Celebrex is still available with the FDA's "black box" warning printed on the label. All three of the drugs were developed to work the same way as standard NSAIDS -- such as ibuprofen, naproxen and aspirin -- without the inherent damage to the stomach associated with the drugs.
In the first study, conducted by the Department of Epidemiology and Nutrition at the Harvard School of Public Health, the researchers analyzed the results of 114 randomized trials of more than 116,000 people.
Vioxx was found to increase the risk of not only irregular heart rhythms, but also adverse kidney events. Bextra and Celebrex did not seem to affect the risk factors associated with these conditions, leading the researchers to suggest that not all cox-2 inhibitors necessarily cause kidney trouble and arrhythmias. In fact, the data -- published in the Sept. 12 online edition of the Journal of the American Medical Association and set to appear in the Oct. 4 print edition -- suggests only Vioxx may have these side effects, the researchers said.
The second study, conducted by researchers at the University of Newcastle in Australia, reviewed 17 studies comparing 86,000 painkiller users with more than 500,000 healthy people in a control group. The researchers found that, as Vioxx dosage increased, so did the risk of heart attack, and that risk was most evident after the first month of use.
Eric Ding, co-author of the Harvard School of Public Health study, was highly critical of Vioxx, saying that more could have been done to identify the drug's side effects before it caused any real damage.
"The risks of these drugs should have been made known to the public much earlier," he said. In addition, "tracking drug safety may be improved by adopting an active and continuous cumulative surveillance system."
Dr. David J. Graham, the associate director for science in the FDA's Office of Drug Safety known for blowing the whistle on both Vioxx maker Merck and the FDA itself, agreed in an editorial accompanying the Harvard study in JAMA.
Graham testified to a special Senate hearing on Vioxx's risks in 2004, and challenged his agency's claims that the drug actually protected people from heart attacks. He also accused the FDA of knowing about Vioxx's dangers before it was approved for marketing.
"It is clear that Vioxx increases the risk of heart attack, and that increase in risk begins with the first tablet a patient takes," Graham said
On Tuesday, the FDA released a statement in response to Graham's editorial. An excerpt claimed that "Dr. Graham's views expressed in the accompanying editorial are his own, and do not reflect the official positions of the FDA. Dr. Graham provides his personal views on the issue of what NSAID he would recommend to patients in need of long-term use of an analgesic, however, the FDA does not believe the available data rise to the level required to support an official FDA regulatory decision regarding comparative safety and efficacy of the available COX2-selective and non-selective NSAIDs."
"It is amazing," added Mike Adams, a consumer health advocate and frequent critic of the FDA's favoritism towards Big Pharma, "that FDA politicians go to such great lengths to try to discredit the carefully-researched conclusions of one of the agency's top drug safety scientists. The FDA is at war with good science," Adams added, "and this war is producing countless casualties among American consumers who naively believed the FDA was trying to protect their health."