Double-blind controlled trial with colloidal bismuth subcitrate in the treatment of symptomatic duodenal ulcers with special references to blood and urine bismuth levels.

To test the efficacy and toxicity of colloidal bismuth subcitrate (CBS) in a double-blind trial, forty-six consecutive outpatients with active duodenal ulceration were randomly allocated either to treatment with CBS or to a placebo for a period of four weeks. Symptomatic assessment was based on frequency and severity of pain. The ulcer size was measured endoscopically before and at the end of the trial. During the trial blood and urinary bismuth concentrations were measured. The symptomatic assessment of the patients receiving CBS or placebo showed that the reduction in pain was highly significant in both groups, but there was statistically significant difference in the degree of reduction of duodenal ulcer size in favour of the colloidal bismuth subcitrate-treated group (p less than 0.025). Although a marked increase in urinary bismuth concentration was noted, the blood bismuth levels remained within the acceptable levels.