Rofecoxib is a NSAID that was used in the treatment of osteoarthritis, acute pain conditions, and dysmenorrhoea. It was marketed by Merck & Co. under the trade names Vioxx, Ceoxx and Ceeoxx, it was voluntarily withdrawn from the market in because of concerns about increased risk of heart attack and stroke.

Rofecoxib was one of the most widely used drugs to be withdrawn from the market. In the year before withdrawal, Merck had a sales revenue of US$2.5 billion from Vioxx.
As of March 2006,, there had been over 10,000 cases and 190 class actions lawsuits filed against Merck over adverse cardiovascular events associated with rofecoxib and the adequacy of Merck's warnings.

The recall and litigation over Rofecoxib has provoked debate over drug safety in the US. Some argue that the FDA does not do enough to monitor product safety. It has also been argued that litigation is an imperfect means of regulation that would overdeter companies for complying with FDA requirements, and that large awards would inhibit research and development.