COX-2 inhibitor

Prostaglandins are made by two different 

 cyclooxygenase-1 (COX-1) 

cyclooxygenase-2 (COX-2) 

 COX-2 inhibitors are NSAIDs that selectively block the COX-2 enzyme and not the COX-1 enzyme. Blocking this enzyme impedes the production of prostaglandins by the COX-2 enzyme that often cause the pain and swelling of inflammation and other painful conditions. Because they selectively block the COX-2 enzyme and not the COX-1 enzyme

these drugs are uniquely different from traditional NSAIDs which usually block both COX-1 and COX-2 enzymes.