Gastroduodenal tolerability of highly specific cyclo-oxygenase-2 inhibitor

Inhibition of constitutively expressed cyclo-oxygenase (COX-1) by NSAIDs is thought to play an important role is the gastrointestinal toxicity of NSAIDs. To minimise the intestinal toxicity of NSAIDS, highly selective COX-2 (induced at inflammatory sites) inhibitors have been developed. One such is flosulide. We assessed the gastroduodenal tolerability of flosulide (20 mg twice a day) in man and compared it with that of naproxen (500 mg twice a day) in a randomised, double blind crossover fashion in 19 patients with osteoarthrosis. Treatment period was 2 weeks with a 2-week washout period with endoscopy before and after each treatment. Gastroduodenal damage was assessed as by Lanza (Grades 0-4) and by the Gastroscopic Rating Scale (Grades 0-9). Flosulide was significantly better tolerated (p < 0.005, analyses of deviance) than naproxen. No stomach damage was seen in 13 (68%) patients following flosulide and 5 (37%) following naproxen (p < 0.001). Lanza scores following flosulide (0.58) were significantly better than that of naproxen (1.47) (p < 0.001). The duodenal damage was mild with both treatments. The selective COX-2 inhibitor, flosulide, is significantly better tolerated and causes less gastric mucosal damage than naproxen when given for two weeks.