Researchers at the University at Buffalo followed 28 patients from the Dent Neurologic Institute who were given both ibuprofen (NSAID) to lessen the arthritis effects on elderly patients and aspirin to minimize the risks of the second stroke. Both drugs were taken on daily basis. The analyses showed that this ibuprofen – aspirin combination may not be advisable as ibuprofen was found to have the potential to destroy aspirin's positive effect on stroke risk. Ibuprofen may be doing so by undermining aspirin's ability to act as an anti-platelet agent.

Thirteen patients who were taking both aspirin and a NSAID (ibuprofen or another) had had a second stroke and had been platelet non-responsive to aspirin i.e. aspirin resistant at the time of the stroke.

When the other 15 of the 28 patients, who had been discontinued NSAID, came back for their second neurological visit, the doctors found that they had regained their aspirin sensitivity and its ability to prevent blood platelets from aggregating and blocking arteries.

Although the aspirin/NSAID interaction has been one of the best-known, but well-kept secrets in stroke medicine, this study is important because it shows the clinical consequences of the aspirin/NSAID interaction in those patients being treated for prevention of a second stroke.

Unfortunately, many of the clinicians are often unaware of this interaction. This new study shows that strokes that occurred in patients who had had received both aspirin and an NSAIDs were preventable.

FDA has warned that ibuprofen could make aspirin less effective, but they also say that clinical implications of the interaction have not been evaluated.