Cyclooxygenase-2 and antagonists in pain management.

Non-steroidal anti-inflammatory drugs are widely used for the treatment of pain and inflammation by inhibiting the formation of prostaglandins. However, their use is limited by their side-effects, including gastrointestinal, renal function, cardiovascular and platelet function. Cyclooxygenase activity is the principal target for the action of non-steroidal anti-inflammatory drugs. Two isoforms of cyclooxygenase have been characterized: (i) cyclooxygenase-1, which is found in many tissues and is generally constitutively expressed and synthesizes prostanoids that mediate homeostatic functions; and (ii) cyclooxygenase-2, the inducible isoform, which is mainly expressed at sites of injury or inflammation and synthesizes prostanoids that mediate inflammation, pain and fever. These findings led to the development of selective cyclooxygenase-2 inhibitors, with comparable anti-inflammatory and analgesic properties to traditional non-steroidal anti-inflammatory drugs, but with significantly fewer side-effects. However, these new selective cyclooxygenase-2 inhibitors are not risk free, and care should be taken when using these drugs, especially with elderly patients with multiple medical problems. Finally, the future is bright for the broader usage of these agents in the treatment of diseases other than inflammation and pain, such as Alzheimer's disease, colonic polyp and colon cancer, just to name a few.