Upper gastrointestinal tolerability of celecoxib compared with diclofenac in the treatment of osteoarthritis and rheumatoid arthritis.

OBJECTIVE To compare the upper gastrointestinal (UGI) tolerability of celecoxib (a cyclooxygenase-2 specific inhibitor) and diclofenac using data from three randomised, double-blind clinical trials in osteoarthritis (OA) and rheumatoid arthritis (RA). METHODS Patients in two OA studies received either celecoxib 100 mg BID (n = 545), diclofenac 50 mg BID or TID (n = 540), or placebo (n = 200) for 6 weeks. In the RA study, patients received celecoxib 200 mg BID (n = 326) or diclofenac 75 mg BID (n = 329) for 24 weeks. The cumulative incidence of abdominal pain, dyspepsia, nausea or any of these events (UGI tolerability composite endpoint) after the first 6 weeks was estimated using time-to-event analysis. RESULTS In the pooled OA trials, the cumulative incidence of the composite endpoint was significantly higher with diclofenac (17.6%; 95% CI: 14.4-20.9%) than celecoxib (11.1%; 95% CI: 8.4-13.8%; p = 0.002) and comparable with placebo (13.3%; 95% CI: 8.1-18.4%; p = 0.157). In the PA trial, the cumulative incidence of the UGI tolerability composite endpoint was also significantly higher with diclofenac (20.7%; 95% CI: 16.3-25.1%) than celecoxib (15.9%; 95% CI: 11.9-20.0%; p = 0.013). Celecoxib was also better tolerated than diclofenac in this trial in terms of the cumulative incidences of abdominal pain (p = 0.031) and dyspepsia (p = 0.062). The results of the UGI tolerability composite endpoint analysis were confirmed using the Cox proportional hazards model to controlfor other predictors of UGI adverse events. CONCLUSION The UGI tolerability of therapeutic dosages of celecoxib was significantly better than diclofenac in patients with RA or OA.