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And I'm Renee Montagne. New evidence suggests that the painkiller Vioxx is even riskier than scientists thought. An estimated 20 million Americans took the painkiller before Merck & Co. stopped selling it in 2004.
The new data show that patients who took Vioxx, even for short periods, were at higher risk of heart problems and strokes. Neither Merck nor the government has released this information. NPR obtained a copy of the company's 107-page report.
Here's NPR's Snigdha Prakash.
SNIGDHA PRAKASH reporting:
In a confidential report to the Food and Drug Administration last week, Merck gave new details about a large Vioxx study. It's known by the acronym APPROVE. Results from the study led Merck to pull Vioxx from the market in 2004. They were later published in the New England Journal of Medicine. The new report includes more heart problems, and several of the new events occurred in Vioxx patients soon after they started taking the drug.
Clinical Trial Expert Curt Furberg, of Wake Forest University, reviewed the new report for NPR. He says it shows short-term users of Vioxx were at greater risk of heart problems than the New England Journal paper said.
Dr. CURT FURBERG (Clinical Trial Expert, Wake Forest University): In The New England Journal of Medicine, it takes about 18 months to see an increase in risk. With the new information, the risk appears to be present from the beginning and it increases gradually over time.
PRAKASH: This point is worth billions of dollars for Merck. Thousands of patients who suffered heart problems are suing the company; many took Vioxx for less than 18 months.
Merck has long said there's no evidence that Vioxx caused those problems. It says the published APPROVE data shows that most of the risk of heart problems was in patients who had been on the drug for much longer than 18 months. And it says the new data from the APPROVE study doesn't change that. The company gave a written statement to NPR, read here by an actor.
Unidentified Man (Actor): (Reading) "The new APPROVE data do not establish that the risk for Vioxx starts earlier than had previously been reported."
PRAKASH: Furberg says Merck's way of analyzing the study is faulty.
Dr. FURBERG: It's not proper, scientifically, to start slicing up the experience in a three-year study and look at it after nine months or 18 or 22. It's not the way it should be done. You look at the total experience and pass judgment on the total experience.
PRAKASH: If you do that, Furberg says, the results show that the risk of cardiac events on Vioxx is almost twice as high over the entire study, including in the early months.
Cardiologist Steven Nissen of the Cleveland Clinic, who also reviewed the report for NPR, agrees that it gives additional evidence that Vioxx is risky from the start.
Dr. STEVEN NISSEN (Interim Chairman of Department of Cardiovascular Medicine, The Cleveland Clinic): Why should a drug have no adverse effect for 18 months and then, all of a sudden, these events would begin to occur? It never made good biological sense.
PRAKASH: Merck's new report also has detailed data on heart problems that patients had after they stopped taking Vioxx. Merck released the bare bones of those findings last week. The company said the data did not show that patients were at greater risk of heart problems after they stopped the drug.
Both Nissen and Furberg disagreed with that interpretation last week. Now, they say the detailed information Merck gave the FDA confirms their opinion: that the risks from Vioxx persist even one year after patients stop taking the drug. They also say the risks are almost as large as when patients are on the drug.
Cardiologist Nissen says this understanding of Vioxx's risks has important practical consequences for patients formerly on the drug, particularly the elderly.
Dr. NISSEN: For example, I have some patients that had previously taken Vioxx and I put them now on low dose of aspirin--which we know has a tendency to reduce the risk of cardiovascular events--as an added protective measure, now that I know they're at increased risk.
PRAKASH: Nissen says there's no telling when or if Vioxx patients will ever lose the disadvantage of having taken the drug. He says Merck should continue to follow patients in this study to find out.
Snigdha Prakash, NPR News, Washington.
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