MEDICATIONS Painkillers can reduce aspirin's heart benefit

The impact of newer drugs such as Celebrex is now being researched.
By JULIE ISHIDA
WASHINGTON POST
Aspirin may fit nicely with Advil and Motrin in your medicine cabinet. But if you use aspirin regularly for its heart benefits, these and other anti-inflammatory painkillers may reduce aspirin's protective effects, according to a new study. Researchers at Boston's Brigham and Women's Hospital, an affiliate of Harvard Medical School, published the findings last week in the online version of the journal Circulation.
Millions of Americans take aspirin to reduce their risk of heart attack and stroke, and for the sizable subset of those people who also regularly use nonsteroidal anti-inflammatory drugs (NSAIDs) for the pain of arthritis and other conditions, the new research may have clinical implications, said the study's lead author, Tobias Kurth.
"Our study provides more evidence that regular users of nonaspirin NSAIDs may not experience the clinical benefit of aspirin," Kurth said. "But we need more data on which specific NSAIDs interfere with aspirin and how to effectively combine these medications for people who need to take both."
The research
Previous studies have suggested that nonaspirin NSAIDs block aspirin's heart-protective effect, but this is the first that focused on risk for a first heart attack. Researchers showed that aspirin did not protect against a first heart attack in regular users of nonaspirin NSAIDs, those who used the drugs 60 or more days per year. But intermittent users of the drugs still received the heart benefit. The study controlled for such factors as age, smoking, exercise and history of other medical conditions such as high blood pressure, diabetes and arthritis.
The findings were based on data from the Physicians' Health Study, in which more than 22,000 healthy male physicians nationwide were randomly assigned to take 325 milligrams of aspirin or a placebo every other day; neither the study participants nor the investigators were aware of any individual's assignment. The participants were surveyed every year about their usage of aspirin and other NSAIDs and whether they had experienced a heart attack.
The trial was halted early, in January 1988, after about five years because aspirin use was found to reduce the risk of a first heart attack by 44 percent.
How it works
Aspirin is thought to reduce the risk of heart attack by binding to an enzyme, called COX-1, that promotes blood clotting. Because aspirin and other NSAIDs share a common docking site on COX-1, the other NSAIDs can occupy these sites instead of aspirin.
A study published in 2001 by the New England Journal of Medicine suggested that regular use of ibuprofen, even taken 12 hours before aspirin, reduces the benefit of aspirin.
The study did not examine the impact of newer NSAIDs, including Celebrex (celecoxib) and Vioxx (rofecoxib), which bind only to the COX-2 form of the enzyme. But researchers are investigating the effect of these newer drugs -- by continuing to follow the Physicians' Health Study participants.