Merck knew Vioxx caused heart attacks but hid the data for years, contributing to an estimated 60,000 deaths

In 2004, Merck pulled Vioxx from the market. The official reason was straightforward: new data had emerged suggesting the painkiller increased the risk of heart attacks and strokes. What wasn't straightforward was what Merck knew beforehand—and when they knew it.

Vioxx had been a pharmaceutical triumph. Launched in 1999, the arthritis and acute pain medication became one of Merck's most profitable drugs, generating over $2 billion annually at its peak. Millions of patients took it. Doctors prescribed it confidently. Then the questions started.

The claim emerged gradually, pieced together by independent researchers, FDA reviewers, and eventually whistleblowers. Internal communications and later court documents revealed that Merck scientists had identified cardiovascular risks years before the public withdrawal. The company, critics argued, had downplayed these findings while continuing to market the drug aggressively. Some estimates suggested Vioxx had caused tens of thousands of deaths.

Merck's initial response was denial wrapped in reassurance. The company disputed the cardiovascular link, citing studies that showed the drug was safe when used properly. They blamed the problems on patient selection—suggesting that people with existing heart conditions were more likely to use Vioxx. This wasn't a cover-up, their position suggested. It was a misunderstanding of the data.

But the evidence told a different story. Dr. David Graham, a senior epidemiologist at the FDA's Office of Drug Safety, conducted a comprehensive analysis. His conclusion was stark: Vioxx had caused between 88,000 and 140,000 excess heart attacks in the United States. He estimated roughly 60,000 of those patients died. When Graham presented these findings to Congress, the scale of the disaster became undeniable.