Vioxx

Vioxx became one of the most prescribed drugs in history.

Thereafter, studies by Merck and by others found an increased risk of heart attack associated with Vioxx use when compared with Naproxen. There was no indication of this risk in the original placebo-controlled safety trials, and it was possible that the effect was more related to Naproxen decreasing the risk of heart attacks than one of Vioxx increasing the risk. Nonetheless, in 2002 Merck adjusted the labeling of Vioxx to reflect possible cardiovascular risks.

On September 23, 2004, Merck received information about results from a clinical trial it was conducting that included findings of increased risk of heart attacks among Vioxx users who had been using the medication for over eighteen months On September 28. Merck notified the FDA that it was withdrawing Vioxx from the market, and it publicly announced the withdrawal on September 30. The FDA has since recommended that Vioxx be put back on the market, but with a more prominent warning regarding cardiovascular risks on its label.

On November 5, 2004 the medical journal The Lancet published the results of its analysis of the available studies. It concluded that “the unacceptable cardiovascular risks of Vioxx (rofecoxib) were evident as early as 2000...”  The Lancet condemned Merck for having kept the drug on the market, despite its knowledge of the risks, and also criticized the FDA for its failure of regulatory oversight.

On August 19, 2005, Merck was found liable in the death of a man who took Vioxx. The plaintiff was awarded $253.4 million in damages, which were subsequently reduced to $20 million, the maximum allowed by Texas statute. In a followup case in New Jersey, Merck was found not liable. A third case is pending in Louisiana. Merck's stock fell $2.35 to $28.06/share (7.73%) in the minutes after the verdict was announced and three months later 7,000 Merck employees were laid off. At the time of the verdict, there were over 4,000 other lawsuits pending against Merck regarding Vioxx, and several thousand against Pfizer, the maker of competing anti-inflammatory drug Bextra, which, in some cases, causes an adverse skin reaction which burns patients "from the inside out."

Merck is currently trying to get a successor drug to Vioxx, called Arcoxia (known generically as etoricoxib) approved in the USA. The FDA has said it will approve Arcoxia if it proves to be safer than Vioxx. Two other drug companies, Pfizer and Novartis, are trying to get alternatives to Vioxx approved. Their drugs are called Dynastat (parecoxib) and Prexige (lumiracoxib), respectively.