Prostaglandin production in the normal gastrointestinal tract, believed to be critical for mucosal integrity, is mediated by cyclooxygenase (COX)-1, whereas prostaglandin production at inflammatory sites seems to occur via induction of COX-2. We hypothesized that COX-2-specific inhibition with rofecoxib (25 mg once daily) in the treatment of patients with osteoarthritis would cause fewer gastroduodenal ulcers than an equally effective dose of ibuprofen (800 mg 3 times a day), a nonspecific COX inhibitor.
A total of 742 osteoarthritis patients without ulcers on baseline endoscopy were randomly assigned to receive rofecoxib (25 or 50 mg once daily), ibuprofen (800 mg 3 times daily), or placebo. Endoscopy was repeated at 6, 12, and 24 weeks. At 16 weeks, by study design, 95% of the placebo group and 5% of the other groups were discontinued.
The cumulative incidence of gastroduodenal ulcers >/=3 mm with rofecoxib (25 or 50 mg once daily) was significantly (P < 0.001) lower than with ibuprofen and was statistically equivalent to placebo at week 12 (placebo, 9.9%; 25 mg rofecoxib, 4.1%; 50 mg rofecoxib, 7.3%; and ibuprofen, 27.7%). At 24 weeks, ulcer rates were 25 mg rofecoxib, 9. 6%; 50 mg rofecoxib, 14.7%; and ibuprofen, 45.8% (P < 0.001, ibuprofen vs. 25 and 50 mg rofecoxib).
Rofecoxib, at doses 2-4 times the dose demonstrated to relieve symptoms of osteoarthritis, caused significantly less gastroduodenal ulceration than ibuprofen, with ulcer rates comparable to placebo.