Vioxx Timeline: 1998-2005

Aug. 25, 2004: Preliminary data from an FDA-financed study show patients who took Vioxx had a higher cardiovascular risk than patients who took Pfizer's (PFE Quote) Celebrex. Merck disputes the study's methodology. The FDA posts a more detailed version of the study on its Web site in November 2004, but says the article hasn't been subject to standard peer review. In early 2005, a version of the article is printed in the medical journal The Lancet.

Sept. 23, 2004: The independent safety monitoring board for the Approve trial recommends that Merck end the trial because of results showing that long-term use of Vioxx -- more than 18 months -- increases risk of heart attacks and strokes compared with patients who took a placebo. There is no difference in risk among patients taking Vioxx or placebo for less than 18 months.

Sept. 30, 2004: Merck says it is withdrawing Vioxx from the U.S. and worldwide markets.

Oct. 29, 2004: Merck receives conditional approval from the FDA for Arcoxia, a cousin of Vioxx. However, this approval is contingent upon Merck completing more long-term safety and efficacy tests. At the time, Arcoxia is sold in 48 countries. Merck says it will work with regulators "to assess whether changes to the prescribing information for this class of drugs, including Arcoxia, are warranted." Merck continues to test and develop Arcoxia for the U.S. market.

Nov. 8, 2004: Merck reveals that its handling of Vioxx is being investigated by the Justice Department and by the Securities and Exchange Commission.

Nov. 18, 2004: The Senate Finance Committee holds a hearing on Merck and the FDA. Dr. David J. Graham, a veteran FDA researcher, accuses the agency of "a profound regulatory failure" in evaluating Vioxx that could easily be repeated with other drugs." Graham is the lead author of the FDA study that criticized Vioxx.

Dec. 23, 2004: The FDA issues a public health advisory urging doctors to weigh carefully the risks in prescribing medications for arthritis and pain, adding that they limit the use of medications known as Cox-2 inhibitors, which includes Vioxx and Pfizer's Celebrex and Bextra. The FDA urges patients to pay closer attention to the labels of certain over-the-counter medications for pain relief.

Feb. 7, 2005: In advance of three days of FDA advisory committee hearings on Cox-2 drugs and other painkillers, FDA staff members issue a report raising questions about two experimental Cox-2 drugs, Arcoxia from Merck and Prexige from Novartis (NVS Quote). The two companies continue to test and develop their drugs for the U.S. market.