Colloidal Bismuth CompoundPosted on 28/2/2008
Used in alloys as components of thermoelectric safety appliances. Bismuth subnitrate and carbonate are used in surgical dressings and bismuth chelate (tripotassium dicitratobismuthate) is used in the treatment of gastric and duodenal ulcers.
Introduction
Mechanism of Action
Bismuth salts precipitate in the acid environment of the stomach and then bind to glycoprotein on the base of an ulcer. The resulting complex adheres to the ulcer and has similar local effects to sucralfate. An additional action which may make a major contribution to ulcer healing is suppression of Helicobacter pylori in most patients, and long-term eradication in 20%.
In brief, it works by selective binding to an ulcer and by coating it to protect the ulcer from acid and pepsin.
Unwanted Effects
- Blackens stools
- Absorption of bismuth chelates from the gut is minimal but in severe renal failure, the inability to excrete the small amounts of absorbed bismuth could produce encephalopathy.
Because of the risk of accumulation of bismuth, courses are usually limited to a maximum of 6 weeks.