Impact of nonsteroidal antiinflammatory drugs on the cardioprotective effects of aspirin.

OBJECTIVE: To examine the evidence of a pharmacodynamic interaction between aspirin and nonsteroidal antiinflammatory drugs (NSAIDs); specifically, to determine whether a deleterious relationship exists with respect to the cardioprotective effects of aspirin. DATA SOURCES: Primary articles were identified by a MEDLINE search (1966-May 2004). Search terms included aspirin, nonsteroidal antiinflammatory drug, drug interaction, mortality, myocardial infarction, and stroke. STUDY SELECTION AND DATA EXTRACTION: All prospective and retrospective studies conducted in human subjects and investigating the potential interaction between aspirin and NSAIDs were included. DATA SYNTHESIS: Several controlled pharmacodynamic studies indicate that the sustained inhibition of cyclooxygenase activity by aspirin is blunted in the presence of some NSAIDs. While these data are fairly consistent, they are limited in that they rely on surrogate markers and not clinical outcomes. Observational studies have shown conflicting results regarding the effect of combination NSAID and aspirin therapy on mortality risk and incidence of myocardial infarction. CONCLUSIONS: Pharmacodynamic data indicating an interaction between aspirin and NSAIDs have not translated to a consistent clinical effect in observational studies. In the absence of a randomized, controlled, clinical outcomes study, there is insufficient evidence to dictate a change in therapy.