A new approach to the treatment of nonsteroidal anti-inflammatory drugs induced gastric bleeding by free radical scavengers.

The effect of the free radical scavengers allopurinol (50 milligrams) and dimethyl sulfoxide (DMSO) (500 milligrams), taken orally four times a day, on the clinical outcome of hematemesis resulting from nonsteroidal anti-inflammatory drugs (NSAID) induced erosive gastritis was examined in a prospective randomized double-blinded controlled trial. In 180 fully evaluable patients with osteoarthritis or rheumatoid arthritis, administration of allopurinol (n = 63) or DMSO (n = 58) enabled significantly (p < 0.01) larger numbers of patients to remain hemodynamically stable with no rebleed relative to those in the control group (n = 59). The results of endoscopic examination 48 hours after admission demonstrated that gastric erosions were still present in significantly more patients in the control group (p < 0.01; n = 20; 50 percent) than in the allopurinol (n = 5; 9 percent) or DMSO (n = 4; 7 percent) groups. The radical scavengers also reduced the number of patients requiring blood transfusion because of a rebleed or continued bleeding and emergency operation relative to control values. It is, thus, construed that oxygen derived free radicals mediate the mechanism of NSAID induced erosive gastritis. Scavenging these radicals impairs the gastritis, stimulates healing and protects against the complications of its hemorrhagic episodes.