Cyclooxygenase inhibitors: any reservations?

The discovery of two cyclooxygenase isozymes, constitutive COX-1 and inducible COX-2, has resulted in the rapid development of selective inhibitors of COX-2, such as celecoxib and rofecoxib. Compared with traditional non-steroidal anti-inflammatory drug agents, use of COX-2 selective inhibitors is associated with decreased incidence of adverse gastric events as a result of minimal inhibition of gastroprotective COX-1, but with equivalent anti-inflammatory benefit through inhibition of COX-2. However, there is evidence to suggest that the 'COX-1 = constitutive, COX-2 = inflammatory' paradigm is less distinct than originally proposed. Futhermore, selective COX-2 inhibitors may have other consequences as a result of the change in the eicosanoid profile. Thus, despite the relatively safe gastrointestinal profile, vigilant post-marketing surveillance for other adverse effects is required.