Many heart patients regularly take aspirin because it thins the blood and prevents the clots that cause heart attacks. Ibuprofen belongs to a widely used class of pain relievers known as nonsteroidal anti-inflammatory drugs. Ibuprofen is widely used for arthritis and other aches and pains. The popular pain reliever ibuprofen blocks the heart-protecting effects of aspirin, according to a study that sounds a warning for people who take both medicines.
In the study, when patients took a single dose of ibuprofen beforehand, aspirin lost 98 percent of its blood-thinning power. When aspirin was taken first, three daily doses of ibuprofen weakened aspirin of 90 percent of its benefit. The researchers believe that ibuprofen clogs a channel inside a clotting enzyme known as cyclooxygenase-1. Aspirin gets stuck and cannot reach its own active site inside the enzyme.
The study found no conflict between aspirin and three other arthritis drugs: rofecoxib, diclofenac, and acetaminophen, which is in Tylenol. But the researchers suggested that other drugs with structures like ibuprofen, such as indomethacin, will similarly block aspirin.
If the study is right, it's more a matter of timing. Aspirin should be taken two hours before ibuprofen. Enteric-coated aspirin, which is released more slowly into the blood, could also be taken at bedtime without a conflict.