THURSDAY, Sept. 30, 2004 (HealthDayNews) -- The maker of the popular arthritis drug Vioxx is removing it from markets worldwide after a new study found that long-term users face increased risks for heart attack and stroke.
The three-year study, designed to see if daily 25-milligram doses of Vioxx might inhibit recurrence of precancerous polyps in the colon and rectum, found the cardiovascular risks began to appear approximately 18 months after starting on the drug.
The 2,600-patient trial was stopped after Merck & Co., the maker of Vioxx, discovered the patients were at elevated risk of heart attack and stroke compared to those taking a placebo.
"While the cause of these results is uncertain at this time, they suggest an increased risk of confirmed cardiovascular events," Peter S. Kim, president of Merck Research Laboratories, said in a prepared statement. He added that "while we recognize that Vioxx benefited many patients, we believe this action is appropriate."
Thursday's announcement came after Merck officials met with representatives of the U.S. Food and Drug Administration on Tuesday to inform them of their decision.
"Merck did the right thing by promptly reporting these findings to FDA and voluntarily withdrawing the product from the market," Acting FDA Commissioner Dr. Lester M. Crawford said in a statement. "Although the risk that an individual patient would have a heart attack or stroke related to Vioxx is very small, the study that was halted suggests that, overall, patients taking the drug chronically face twice the risk of a heart attack compared to patients receiving a placebo."
Vioxx, one of a class of cox 2 inhibitor anti-inflammatory medications that also includes Celebrex, has been one of the biggest-selling drugs on the market, earning more than $2.5 billion for Merck in 2003 alone. Cox 2 inhibitors are designed to treat arthritis without the gastrointestinal damage caused by other medications.
This latest study is not the first to suggest that long-term Vioxx use might harm cardiovascular health. In June 2000, Merck submitted the results of a safety study indicating an increased risk of cardiovascular events in patients taking Vioxx versus the drug napoxen (Aleve). Those findings prompted the FDA to mandate labeling changes for Vioxx.
And in August, a study involving more than 40,500 members of the Kaiser Permanente HMO found that rates for heart attacks and sudden cardiac death were tripled in patients taking the drug at doses greater than 25 milligrams a day, compared to those taking Celebrex.
At the time, Vioxx was already on the "non-preferred" list of arthritis medications at major health insurers such as Cigna Healthcare and Aetna, meaning it was prescribed only to patients who could not use other, equivalent medications.
Patients with a long history of taking Vioxx should not necessarily be alarmed by these findings, said Dr. Michael Fleming, president of the American Academy of Family Physicians.
"It's very difficult to translate findings from a population-based study into individual patients," he said. "If someone is taking Vioxx presently, they need to call their physician right away" to consult on the potential need for specific tests.
"However, from a population standpoint, the likelihood is very low that any one individual patient would be affected," he added.
For arthritis patients, effective alternatives to Vioxx do exist, Fleming added. "There are several anti-inflammatory medicines that have the same effect as Vioxx, and there are several in the same class -- the cox 2 inhibitors. So patients need to discuss this with their physicians."
In a statement Thursday announcing the withdrawal, Merck Chairman and CEO Ray V. Gilmartin said: "We're taking this action because we believe it best serves the interests of patients. Although we believe it would have been possible to continue to market Vioxx with labeling that would incorporate these new data, given the availability of alternative therapies and the questions raised by the data, we concluded that a voluntary withdrawal is the responsible course to take."
Crawford said his agency also plans to monitor other cox 2 inhibitors closely in the coming years for similar cardiovascular problems. "All of the NSAID (non-steroidal anti-inflammatory) drugs have risks when taken chronically, especially of gastrointestinal bleeding, but also liver and kidney toxicity. They should only be used continuously under the supervision of a physician," he advised in a statement.
The FDA first approved Vioxx in 1999 for the prevention and treatment of pain inflammation caused by osteoarthritis.
Karen Reed is on the board of trustees of the American Pharmacists Association, representing 50,000 pharmacists nationwide. She said pharmacists "were all surprised by the announcement today." However, she added that "there had been concerns about answering questions about the product for some time."
Reed worries that patients currently on Vioxx might "self-medicate" now that the drug has been pulled. This might mean switching to an over-the-counter (OTC) alternative before consulting with a doctor or pharmacist.
"People who take Vioxx are in chronic pain because of arthritis," she said. "They are looking for relief and now they are afraid to take a trusted product that was recalled today. So they might jump to the OTC products and start taking those, which have risks as well. Before they do that they should seek help on this from their pharmacist."
"What I would encourage patients to do is to contact their pharmacist or their doctor and find out alternatives that would be suitable for them," Reed said.
More information
For more on Vioxx, visit the U.S. Food and Drug Administration.