Do Other NSAIDs Interfere with Aspirin?

Data from laboratory studies suggest that use of other nonsteroidal anti-inflammatory drugs (NSAIDs) may antagonize aspirin's platelet-inhibiting effects. This interaction could have important consequences because many patients who take aspirin to prevent vascular disease also take other NSAIDs.

In this randomized crossover study, one group of 6 participants took aspirin (81 mg) 2 hours before receiving ibuprofen (400 mg) for 6 days and then, after a washout, received the same 6-day regimens in reverse order; in a second 6-person group, acetaminophen (1000 mg) was substituted for ibuprofen; in a third 6-person group, rofecoxib (25 mg) replaced ibuprofen. Platelet inhibition was assessed by measurements of thromboxane B₂ and of platelet aggre…