What did the FDA know about the risk of heart attack and stroke when it approved Vioxx?
The FDA originally approved Vioxx in May 1999. The original safety data included approximately 5,000 patients taking Vioxx and did not show an increased risk of heart attack or stroke. A later study, VIGOR (VIOXX Gastrointestinal Outcomes Research), was primarily designed to look at the effects of Vioxx on gastrointestinal (GI) side effects such as stomach ulcers and bleeding and was submitted to the FDA in June 2000. The study showed that patients taking Vioxx had fewer stomach ulcers and bleeding than patients taking the over-the-counter drug naproxen. However, the study also showed that patients taking Vioxx were four times more likely to have a heart attack, stroke or other serious cardiovascular event. The VIGOR study was discussed at a February 2001 Arthritis Advisory Committee, and the new safety information from this study was added to the Vioxx labeling in April 2002. Merck then began to conduct longer-term trials to obtain more data on the risk for heart attack and stroke ass
