The role of COX-2 in acute pain and the use of selective COX-2 inhibitors for acute pain relief

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the mainstay of therapy for the management of acute pain. Cyclooxygenase (COX) enzyme is of particular interest because it is the major target of NSAIDs. Although NSAIDs are remarkably effective in the management of pain and inflammation, their use is limited by several adverse effects including gastrointestinal bleeding and ulceration, impaired renal function, and inhibition of platelet aggregation. Discovery of a second cyclooxygenase, COX-2, led to the hypothesis that NSAID side effects could be decreased, as the inhibition of COX-2 is more directly implicated in ameliorating inflammation while the inhibition of COX-1 is related to adverse effects in the GI tract. This stimulated the development of selective COX-2 inhibitors (coxibs) that are better tolerated than nonselective NSAIDs but comparable in analgesic efficacy. This article provides an overview on the therapeutic use of selective COX-2 inhibitors for relief of acute pain, largely based on clinical trials in patients undergoing the surgical removal of impacted third molars, with focus on analgesic efficacy and the potential safety associated with their use compared to dual COX-1/COX-2 inhibitors.