title: Oxygen-derived free radicals and the prevention of duodenal ulcer relapse: a new approach.
abstract: This study investigated whether or not oxygen-derived free radicals are implicated in the mechanism of recurrence of duodenal ulceration. To this end, allopurinol (50 mg qds)--a hydroxyl scavenger and an inhibitor of xanthine oxidase which forms superoxide radicals--and dimethyl sulphoxide (DMSO, 500 mg qds)--a hydroxyl scavenger--were given orally. Three hundred and two consecutive patients with previous symptomatic, endoscopy-proven duodenal ulceration which had been shown endoscopically to have healed and who were smokers and social drinkers, were randomized to receive for one year either placebo, cimetidine 400 mg at bedtime, allopurinol, or DMSO. In two hundred and twenty patients evaluable for efficacy, the cumulative relapse at one year was: placebo 65%, cimetidine 30%, allopurinol 12% and DMSO 13%. Cimetidine was significantly effective (p less than 0.01); however, allopurinol and DMSO were equally efficacious and superior to cimetidine (p less than 0.05). In patients who relapsed, the ulcer recurrence tended to occur early on placebo and to be evenly distributed over the year on active therapy. In all the groups, the relative frequency of symptomatic to silent relapses was similar in the first and second halves of the year and was comparable among the groups. The results suggest that oxygen-derived free radicals are directly implicated in the mechanism of duodenal ulcer relapse and that removing the radicals reduces recurrence of this ulceration.
authors.affiliation: University Department of Surgery, The Medical City, Baghdad, Iraq.
authors.forename: A S
authors.initials: AS
authors.lastname: Salim
mesh_terms: D000493:Allopurinol / Q000627:therapeutic use*; D002927:Cimetidine / Q000627:therapeutic use*; D004121:Dimethyl Sulfoxide / Q000627:therapeutic use*; D004381:Duodenal Ulcer / Q000503:physiopathology / Q000517:prevention & control*; D005260:Female; D005500:Follow-Up Studies; D005609:Free Radicals; D006801:Humans; D006878:Hydroxides; D017665:Hydroxyl Radical; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011897:Random Allocation; D012008:Recurrence; D012907:Smoking / Q000503:physiopathology
chemical_list: D005609:Free Radicals; D006878:Hydroxides; D017665:Hydroxyl Radical; D000493:Allopurinol; D002927:Cimetidine; D004121:Dimethyl Sulfoxide