Bismuth (Bi)

Bismuth is a post-transition metal with the atomic number 83, primarily recognized in medicine for its use in treating various gastrointestinal ailments. It is not a biological target such as a receptor or enzyme, but rather a therapeutic element found in drugs like bismuth subsalicylate and bismuth subcitrate (Wikipedia, Bismuth). Bismuth compounds are a cornerstone of quadruple therapy for Helicobacter pylori eradication, where they function by inhibiting bacterial enzymes and disrupting the microbial cell membrane (NCBI, PMC5518599). Beyond its antimicrobial properties, bismuth provides cytoprotection by forming a physical barrier over gastric ulcers and stimulating endogenous mucosal protective factors. It also exhibits anti-secretory and anti-inflammatory properties, which contribute to its effectiveness in treating diarrhea and dyspepsia (StatPearls, NBK537071). While generally well-tolerated for short-term indications, excessive or prolonged use can lead to systemic accumulation and serious adverse effects, most notably bismuth-induced encephalopathy. The metal's unique ability to bind to various bacterial proteins makes it a versatile agent in overcoming antibiotic resistance in H. pylori infections.

Other names

BiAtomic number 83BismuthumBismuth metal

Bismuth compounds exert their therapeutic effects through several mechanisms: they act as bactericidal agents against Helicobacter pylori by disrupting cell wall integrity and inhibiting essential enzymes like urease and alcohol dehydrogenase (PubChem CID 5359367). In the gastrointestinal tract, bismuth reacts with gastric acid to form bismuth oxychloride and salicylic acid (in the case of subsalicylate), providing a protective coating over ulcerated tissue to shield it from acid and pepsin (StatPearls, NBK537071). It also stimulates the synthesis of prostaglandins, bicarbonate, and mucus, enhancing mucosal defense mechanisms (Alkim et al., 2017).