Background/aims: Our investigations was carried out in order to examine the effect of cimetidine, ranitidine and famotidine on the generation of free radicals, lipid peroxidation and enzymatic antioxidative defense in the blood of patients with peptic ulcer disease, clinically diagnosed as gastric or duodenal ulcer.
Methodology: 124 non-smoking males (aged 20-51 years), were randomly divided into 4 groups: 28 patients received intravenously 200 mg of cimetidine; 26 patients intravenously 50 mg comprised of ranitidine; 25 patients received intravenously 20 mg of famotidine; and 45 healthy men served as the control group. Superoxide dismutase activity, malonyldialdehyde concentration in blood platelets and superoxide anion generation in granulocytes were determined in all examined men. An assay of superoxide dismutase activity and malonyldialdehyde concentration were performed before drug administration and after 2 and 72 hours. Superoxide anion generation was estimated before drug administration and after 2 hours.
Results: Our data indicate that all examined H2 receptor antagonists stimulate superoxide dismutase activity, but after 72 hours a distinct increase was observed, in addition to a decrease of malonyldialdehyde concentration. No differences have been observed in superoxide anion generation in patients with ulcer disease or in healthy subjects before and after ranitidine and famotidine administration. Only after 2 hours of cimetidine administration was a significant increase in superoxide anion generation observed.
Conclusion: We concluded that H2 receptor antagonists have a beneficial effect on antioxidative processes.