Mechanism of action of nonsteroidal anti-inflammatory agents.

Recent data from several laboratories, which suggest that generally accepted concepts relating to the mechanism of action of nonsteroidal, anti-inflammatory drugs (NSAIDs) in rheumatoid arthritis may be incorrect, are reviewed. Over the past decade, most researchers have espoused the idea that NSAIDs act by inhibiting cyclooxygenase, thereby removing prostaglandins, which are thought to be responsible for pain and inflammation. Recent studies demonstrating that prostaglandins have important immunomodulating properties and that NSAIDs actually provide partial correction of several immunoregulatory dysfunctions in patients with rheumatoid arthritis are described. In addition, some NSAIDs inhibit migration along with other monocyte and polymorphonuclear leukocyte functions. Data suggest that these actions are not related to inhibition of cyclooxygenase.