The identification of two cyclooxygenase (COX) enzymes has been a tremendou
s advance in understanding the role of prostaglandins in inflammation and t
he actions of nonsteroidal antiinflammatory drugs (NSAIDs). COX-1 activity
appears to be related to "constitutive" or "house-keeping" functions in the
gastric mucosa, kidney and platelets. COX-2 activity is "inducible" and ge
nerally occurs in response to a specific stimulus to enhance inflammatory a
ctions. Current NSAIDs inhibit both COX-1 and COX-2, although the clinical
benefit of NSAIDs appears to be associated with inhibition of COX-2 activit
y. The inhibition of COX-1 activity by NSAIDs is related to adverse side ef
fects in general, particularly gastrointestinal toxicity. Recently, COX-2 s
elective inhibitors have been developed. Current data would suggest that by
inhibiting COX-2 action, these agents may have efficacy similar to that of
standard NSAIDs and that by not inhibiting COX-I activity, they may have l
ess toxicity than standard NSAIDs. Thus, these actions indicate that COX-2
selective inhibitors will have similar clinical efficacy to the traditional
NSAIDs with fewer adverse side effects. (C) 1999 Prous Science: All rights
reserved.