What have efficacy studies of NSAIDs found?
In general, there are no important differences among the various NSAIDs in terms of “comparative effectiveness”, although there are clear individual variations in response. In some arthritic diseases, specific NSAIDs have been traditionally used as first-line agents over others. This is typically based on the evidence of clinical effectiveness of a drug for a particular condition, rather than evidence of superiority over other NSAIDs. For example, in gout and seronegative spondyloarthropathies, indomethacin is often the initial drug of choice.
There is no clear relationship between the amount of COX inhibition and effectiveness of a particular agent for treatment of arthritis. Although the pharmacodynamics of the drug is important in a given individual, there is no good correlation between the plasma level of the drug and efficacy except for salicylates.