Clinical experience with cyclooxygenase-2 inhibitors.

Increasing amounts of experimental and clinical data support the role of selective cyclooxygenase (COX)-2 inhibition in anti-inflammatory processes and the role of COX-1 inhibition in increasing the frequency of side effects. This article reviews the regulation of COX-2 in inflammatory processes based on in vitro and in vivo work. In addition, it summarizes the various in vitro assays used to classify the new generation of selective and highly selective inhibitors of COX-2, since prior categorization of NSAIDs does not satisfactorily encompass the COX-2 concept. Finally, the latest published clinical data of new selective and highly selective inhibitors of COX-2 (meloxicam, nimesulide, etodolac, celecoxib and MK966) are discussed.