Assessment of the safety of selective cyclo-oxygenase-2 inhibitors: where are we in 2003?

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely used drugs worldwide despite their well-documented adverse gastrointestinal (GI) effects. The risk of developing a severe GI event varies from patient to patient and NSAID to NSAID. Selective cyclo-oxygenase-2 inhibitors (coxibs) have been designed to have similar efficacy but less GI toxicity than traditional NSAIDs, and have been shown to have an improved GI tolerability and less adverse events across a range of different GI safety assessments. In clinical trials, particularly VIGOR and CLASS, rofecoxib and celecoxib, respectively, significantly reduce the risk of ulcers and ulcer complications than nonselective NSAID comparators with ulcer rates comparable to placebo. The real benefit of a coxib comes from the sparing of the thromboxane and hence preservation of normal platelet function. Thus, there is less risk of bleeding with selective inhibition of COX-2, which is the most common and serious complication of non-selective NSAIDs. Moreover, bleeding can occur anywhere in the GI tract. Although some concern has been raised about the cardiovascular safety of coxibs, when used in recommended doses, there is no convincing evidence that patients treated with a coxib have an increased risk of cardiovascular thrombotic events. Different approaches have been advocated to minimize NSAID-related GI toxicity. Choice of less harmful NSAIDs such as coxib has been one of the strategies promoted in guidelines. The introduction of coxibs with a higher benefit-risk ratio has dramatically changed the therapeutic scenario for anti-inflammatory treatment in the clinical practice.