Ibuprofen Cripples Aspirin's Heart Benefits
Posted by Mike Kremer on Dec 21, 2001 at 05:14
usera074.dsl.pipex.com (62.188.48.74)BOSTON (Reuters) - The painkilling drug ibuprofen can cripple aspirin's ability to protect against a heart attack, researchers report in Thursday's New England Journal of Medicine.
The results, if confirmed, would have major implications for millions of people who take a small dose of aspirin every day to thin the blood, but who also take ibuprofen, widely known in North America under the brand name Advil, to cope with conditions such as arthritis.
In a series of tests, a team from the University of Pennsylvania School of Medicine led by Dr. Francesca Catella-Lawson, found that ibuprofen set up a chemical blockade that prevented aspirin from thinning the blood.
They found that if aspirin was given two hours before the ibuprofen, aspirin had time to lower the risk of clotting. When taken together, aspirin lost its effectiveness.
In theory, people could simply take aspirin first. But the researchers noted that most patients take ibuprofen, which belongs to a class of medicines known as nonsteroidal anti-inflammatory drugs, continuously to control arthritus.
When the Catella-Lawson group gave a dose of aspirin in the morning to people who hadn't taken their Advil since late the previous night, they found there was still enough Advil in the blood to block aspirin's blood-thinning effects.
"Multiple daily doses of ibuprofen can undermine the cardioprotective effects of a daily aspirin regimen," according to coauthor Garret FitzGerald.
Other painkillers such as diclofenac (best known under the brand name Voltaren by Novartis AG ), acetaminophen (Tylenol), and refocoxib (sold under the brand name Vioxx by Merck ) did not produce the same problem.
FitzGerald said people ``taking aspirin to protect against heart attack should seek the advice of their doctors before commencing additional treatments for pain and inflammation.In related research published in the same issue of the New England Journal, doctors in Sweden and Nashville found that aspirin and acetaminophen seemed to increase the risk of long-term kidney failure.
Using medical records and interviews from Swedes, both with kidney failure and without, Dr. Michael Fored of the Karolinska Institute in Stockholm found the 926 people with kidney failure were 2.5 times more likely to have been regular users of aspirin and acetaminophen than the 998 without kidney problems.Leslie Crofford of the University of Michigan in Ann Arbor, in an accompanying editorial, noted the problem wasn't seen in people taking a low dose of aspirin to prevent a heart attack, and people without any preexisting kidney disease faced a low risk of kidney failure, even if they were taking the aspirin and the nonsteroidal anti-inflammatory drugs.