Vioxx Troubles Known, Prof SaysDec 2, 2004 | The Daily University of Washington-Seattle Serious problems with U.S. systems for prescription drug approval and post-marketing surveillance threaten public health, according to a UW epidemiologist.
Bruce Psaty, a UW professor of epidemiology and internationally recognized expert on drug safety, testified before a Senate panel that examined the recent withdrawal of the prescription painkiller Vioxx from the market in response to findings that linked Vioxx with an increased risk for heart attacks on Nov. 18.
At the hearing, Psaty criticized Merck, the manufacturer of Vioxx, for designing its clinical trials to avoid exposing the drug's cardiovascular risk.
"There are things that you can do in studies, to ask particular questions and not ask particular questions ... In the way they (Merck) set up this package of studies, they minimized the chance of finding any cardiovascular harm," said Psaty.
To prevent future problems with drugs like Vioxx, Psaty emphasizes the need to reform the nature of clinical trials.
"These are chronic disease medications, and people are taking them for many years," explained Psaty. "The optimal way to assess the risks and benefits are to do large, long term trials that evaluate the risks and benefits in those populations ... Merck did not do this and the FDA (Food and Drug Administration) did not insist on it."
Psaty suggests that large clinical trials should follow at least 5,000 people for several years.
Psaty's testimony before Congress coincides with the publication of an article he co-authored, "Potential for Conflict of Interest in the Evaluation of Suspected Adverse Drug Reactions," in the Journal of the American Medical Association.
The article, which has attracted the attention of national news organizations such as The Wall Street Journal and The New York Times, focuses on the Bayer Corporation's failure to communicate findings regarding safety concerns about the cholesterol-lowering drug Baycol to doctors and patients.
"What [the epidemiological community is] concerned about is that the companies may have a conflict of interest in their interpretation of the adverse event drug reports, and that they may have too high a threshold for acting when looking at these adverse events," said Psaty. "It's very easy [for the drug companies] to say, well, maybe this data isn't so good, maybe we need to study it some more."
In order to avoid such conflicts of interest, Psaty advocates for an independent office of drug safety at the federal level.
Under the current system, the FDA's Office of New Drugs is required to review any changes in the labeling of drugs after they have been approved.
"In effect, they (the FDA) have to admit that they may have been wrong in how they approved the drug, and so they are reluctant in how they make the changes," said Psaty.
As an example, Psaty points to a trial of Vioxx that showed a five-fold increase in heart attacks in comparison to Naproxen, an older painkiller. It took two years for Merck to revise Vioxx's label to reflect the results of the trial.
Psaty also cites the FDA's rejection of Dr. David Graham's criticism of the current system as an example of the agency's problems. Graham, an FDA researcher, testified alongside Psaty at the Senate hearing, where he sharply criticized the FDA's procedures for post-marketing surveillance.
"Instead of embracing [Graham] and his concerns about safety, they've ostracized him. He's done the best study on Baycol, the best study on Vioxx ... It's unfortunate that the FDA responds to this high quality work by trying to discredit him," said Psaty.
Despite the size of the problem, Psaty is excited by the recent media attention devoted to the issue of drug safety.
"I am hopeful, if not exactly confident, that this issue will be addressed in the next year or so. It's a recognized problem. There's been a convergence of events, and I'm hopeful that there will be responses," said Psaty.