Aim: To investigate the efficacy and safety of daily low-dose colloidal bismuth subcitrate in reducing duodenal ulcer relapse.
Design: Double-blind, double-dummy group comparative clinical trial with random allocation. Healing Phase: colloidal bismuth subcitrate 240 mg twice daily vs ranitidine 150 mg twice daily for up to 12 weeks. Maintenance Phase: nightly, colloidal bismuth subcitrate 120 mg vs ranitidine 150 mg vs placebo for up to 12 months (high-risk patients received active treatment only).
Assessment: clinical, endoscopy, random blood bismuth levels (and rapid urease test for Helicobacter pylori in a subgroup).
Patients: 194 with active duodenal ulcer.
Outcome: Cumulative healing at 12 weeks was 93% on colloidal bismuth subcitrate (of 92 patients) and 97% on ranitidine (of 102 patients). Relapse at 1 year was significantly less on active treatment as follows: placebo (50 patients) 60%; ranitidine (71 patients) 21%; colloidal bismuth subcitrate (64 patients) 33%. This was independent of the results of the rapid urease test which was positive in 78%, 88% and 76% of the patients respectively. Treatment was well tolerated. The highest median blood bismuth level (mcg/L) was 25 in the healing phase and fluctuated between 6 and 10 in the maintenance phase.
Conclusions: Colloidal bismuth subcitrate, 120 mg nightly, is effective in reducing duodenal ulcer relapse and is well tolerated.