Efficacy of cyclooxygenase-2-specific inhibitors.

Conventional nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit both cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). The clinical efficacy of NSAIDs is primarily related to the inhibition of COX-2 activity, whereas much of the toxicity, particularly gastrointestinal toxicity, is related to COX-1 inhibition. In vitro and in vivo assays indicate that both COX-2-specific inhibitors and conventional NSAIDs are equally effective in inhibiting COX-2, suggesting that the clinical efficacy of COX-2-specific inhibitors should be similar to that of conventional NSAIDs. Multiple studies in patients with osteoarthritis, rheumatoid arthritis, and acute pain have now confirmed that the clinical efficacy of COX-2-specific inhibitors is similar to that of conventional NSAIDs.