Allegations that unsafe drugs are approved
Some critics believe that the FDA has been too willing to overlook safety concerns in approving new drugs, and is slow to withdraw approved drugs once evidence shows them to be unsafe. Rezulin (troglitazone) and Vioxx (rofecoxib) are high-profile examples of drugs approved by the FDA which were later withdrawn from the market for posing unacceptable risks to patients.
Troglitazone is a diabetes drug that was also available abroad at the time the FDA approved it. Post-marketing safety data indicated that the drug had dangerous side-effects (in this case liver failure). The drug was pulled off that market in the UK in 1997, but was not withdrawn by the FDA until 2000, before which time it is claimed that thousands of Americans were injured or killed by the drug.
In the case of Vioxx, a pre-approval study indicated that a group taking the drug had four times the risk of heart attacks when compared to another group of patients taking another anti-inflammatory, naproxen. The FDA approval board accepted the manufacturer's argument that this was due to a previously unknown cardioprotective effect of naproxen, rather than a risk of Vioxx, and the drug was approved. In 2005, the results of a randomized, placebo-controlled study showed that Vioxx users suffered a higher rate of heart attacks and other cardiovascular disorders than patients taking no medication at all. Faced with numerous lawsuits, the manufacturer voluntarily withdrew it from the market in 2004. The example of Vioxx has been prominent in an ongoing debate over whether new drugs should be evaluated on the basis of their absolute safety, or their safety relative to existing treatments for a given condition.
David Graham, a scientist in the Office of Drug Safety within the CDER, testified to Congress that he was pressured by his supervisors not to warn the public about dangers of drugs like Vioxx. He argued that an inherent conflict of interest exists when the office responsible for post-approval monitoring of drug safety is controlled by the same organization which initially approved those same drugs as safe and effective. In a 2006 survey sponsored by the Union of Concerned Scientists, almost one-fifth of FDA scientists said they "have been asked, for non-scientific reasons, to inappropriately exclude or alter technical information or their conclusions in a FDA scientific document."