Evidence Mounts Against Vioxx-Class PainkillersFeb 16, 2005 | www.ipsnews.ne In an exclusive interview, a prominent scientist attending U.S. Food and Drug Administration (FDA) hearings on the safety of a class of painkillers known as COX-2 inhibitors this week says that one drug in particular may be more dangerous than previously thought.
Dr. Curt Furberg was part of the team behind a recently published study on Pfizer's Bextra that found more than a threefold increase in the risk of heart attacks among people who took the drug following bypass surgery. He is also a member of the FDA advisory committee for Drug Safety and Risk Management.
Concerns over a five-fold increased risk of heart attacks and strokes for Merck & Co's similar pain reliever Vioxx led to that drug's market withdrawal last Sep. 30.
Pfizer's Celebrex, the most popular COX-2 arthritis medication, has also been found to increase the risk of heart attacks. Pfizer agreed to halt consumer advertising of Celebrex but the drug is still available, as is Bextra.
Furberg told IPS that new ”open source” information not previously in the public domain had emerged showing ”that people who take Bextra for acute pain or chronic pain are at the same increased risk of heart attacks as people who (take the drug following) bypass surgery.”
”The (study) findings can now be broadened, and probably would apply to most users of Bextra,” he said. ”It turns out that the cloud over Bextra is getting darker and darker.”
Furberg gave an estimate of 10 heart attacks or strokes, including four fatalities, per 1,000 Bextra users per year.
Bextra is used by at least seven million people around the world, primarily in the United States, Europe, Canada, South Africa and some countries in Latin America. Last year, Pfizer reported Bextra sales of 1.3 billion dollars. Repeated calls to Pfizer were not returned.
An unusual, three-day FDA meeting started Wednesday to weigh the risks and benefits of Bextra and other COX-2 inhibitors. Furberg foresaw differing views on the available data, and emphasised that ”I'll keep an open mind.”
The 15-member FDA committee, whose members are drawn from academia, public health and industry, will ultimately decide whether Celebrex and Bextra should be withdrawn, or whether their warning labels should be strengthened.
”Some members of the committee were the ones who originally approved the drug (Bextra),” Furberg added. ”It's possible that they're going to be more inclined to leave the drug on the market.”
Furberg's statement parallels what critics like Iowa Senator Charles Grassley see as a structural FDA problem.
Only recently, Furberg was presented with an honorary degree by Sweden's prestigious Umea University for his efforts ”to promote honesty and integrity in research”.
But last November, controversy erupted when Furberg was ”disinvited” to attend the FDA meetings. The rebuff coincided with the widely-publicised Bextra study examining bypass surgery, in which he had participated.
The world-renowned cardiovascular epidemiologist was quoted in a Nov. 10, 2004 article in the New York Times saying: ”Basically, what we showed is that Bextra is no different than Vioxx, and Pfizer is trying to suppress that information.”
He subsequently received a call from officials at the FDA telling him that he was no longer welcome at the meetings, Furberg related.
The Wall Street Journal quoted the acting director of the FDA's office of new drugs as saying there was a potential conflict of interest because Furberg had publicly expressed a negative opinion on the drug. Furberg said he didn't believe his opinions were biased, merely ”evidence-based”.
Furberg told IPS that following the Journal article, he received ”a call from a high official at the FDA saying that 'we are very, very sorry, this is a mistake. You are not off the committee'.”
He has since received the committee materials, and said that the potential conflict of interest forms required from all committee members were received and cleared by FDA.
”I'm all set for the meeting and it's going to be a very interesting meeting,” Furberg said.
The FDA has come under increasing criticism for a pro-industry bias, with many politicians and consumer advocates arguing that the drug safety division lacks sufficient independence and resources.
Sen. Grassley recently charged that ”instead of listening to its best scientists, the agency is sitting down to negotiate with drug companies,” with debacles like the Vioxx scandal being the result.
On Tuesday, the FDA announced that it would create a new drug safety board to improve the ongoing monitoring of medicines already sold in the marketplace.