[Cycloxygenase-2 inhibitors nonsteroid anti-inflammatory drugs: current issues.].

BACKGROUND AND OBJECTIVES Due to the high incidence of NSAID-related side-effects, the discovery of two cycloxygenase isoforms, classified as: COX-1 or constitutive and COX-2 or inductive, has formulated the paradigm that NSAIDs anti-inflammatory properties would be mediated by COX-2 inhibition, and side-effects, by COX-1 blockade. However, COX-2 has been constitutively detected in normal tissues raising the question of how really safe are specific inhibitors of such enzyme. This review aimed to report new clinical and experimental evidences involving COX-2 and its specific inhibitors. CONTENTS New concepts on structural differences between COX-1 and COX-2, the existence of these isoforms in different organic tissues, and animal and human experiments are reported, in addition to clinical observations of specific COX-2 inhibitors (coxibs). Potential new therapeutic indications of NSAIDS, mainly coxibs, for Alzheimers disease and cancer are emphasized. CONCLUSIONS Coxibs are an important pharmacological advance for anti-inflammatory treatment, decreasing the incidence of gastrointestinal adverse effects and probably playing a role in the prevention of cancer and neurological diseases. However, similar side-effects from conventional NSAIDs still exist, and also, coxibs are high-cost drugs. Like any new medication, further evaluations are needed to determine the actual safety profile of such compounds.