There is no evidence to suggest one NSAID is more effective than another in treating pain or morning stiffness in AS, a review of short term studies shows.

According to the network meta-analysis 15 NSAIDs were significantly better than placebo in reducing pain.

When it came to comparing NSAIDs and pain reduction etoricoxib was significantly better than celecoxib, ketoprofen and tenoxicam in reducing pain; however the authors noted that this finding was based on one trial.

 There were no significant differences among NSAIDs in decreasing morning stiffness or in the risk of adverse events, they reported in the Annals of the Rheumatic Diseases.

A large multi-arm trial was needed to test the relative efficacy and safety of NSAIDs in AS, concluded the researchers from the National Institute of Arthritis and Musculoskeletal and Skin Diseases in Maryland, US.