Double-blind comparison of absorbable colloidal bismuth subcitrate and nonabsorbable bismuth subnitrate in the eradication of Helicobacter pylori andthe relief of nonulcer dyspepsia

Background. Bismuth is widely used for the eradication of H. pylori, especi ally in developing countries, although there are concerns over its neurotox icity. Whether bismuth has to be absorbed in humans to act against H. pylor i is not known. In this study, we compared "absorbable" (colloidal bismuth subcitrate) and "nonabsorbable" (bismuth subnitrate) bismuth as part of tri ple therapy in the eradication of H. pylori. Materials and Methods. A double-blind, randomized, placebo-controlled trial was carried out with 120 H. pylori-positive patients with nonulcer dyspeps ia. Group CBS + Ab (n = 35) received colloidal bismuth subcitrate (one tabl et qds), amoxicillin (500 mg qds), and metronidazole (400 mg tds). Group BS N + Ab (n = 35) received bismuth subnitrate (two tablets tds) and the same antibiotics. Group Ab (n = 35) received placebo bismuth (two tablets tds) a nd the antibiotics. Group BSN (n = 15) received bismuth subnitrate (two tab lets tds) and placebo antibiotics. Bismuth was taken for 4 weeks and the an tibiotics for the first 2 weeks. H. pylori eradication, side effects, compl iance, pre- and post-treatment symptom scores, and bismuth absorption were assessed. Results. H. pylori eradication was 69%, 83%, 31%, and 0% in CBS + Ab, BSN Ab, Ab, and BSN, respectively. Side effects, compliance, and symptom relie f were similar in all groups, but blood bismuth levels were significantly g reater in CBS + Ab than the other three groups. Conclusion. The efficacy of bismuth-based therapies as part of triple thera py in the eradication of H. pylori is unrelated to absorption. Hence, the u se of effective but poorly absorbed bismuth preparations should be encourag ed for bismuth-based eradication therapies.