Aspirin-like nonsteroidal antiinflammatory agents, corticosteroids, and methotrexate are the mainstays of therapy in rheumatoid arthritis and other inflammatory diseases. It is now clear that these agents share at least one characteristic: All of these agents diminish the adhesive interactions required for the accumulation of white blood cells at an inflamed site. We discuss the biochemical and functional mechanisms by which these drugs alter the inflammatory response, and the potential for development of new antiinflammatory agents based upon these pharmacological actions.