Bismuth is incorporated into low melting point alloys, glass and ceramics and some of its compounds are used for pigments. Several bismuth preparations have therapeutic activity in the treatment and prevention of gastric and duodenal ulcers.
Although the mechanism of action is not fully understood, it may include suppression of Helicobacter pylori.
Toxicity
Some patients treated with bismuth compounds have enhanced absorption with high concentrations in blood and in urine. For example, bismuth absorption from chelate bismuth markedly increases with gastric acid suppression. Abnormal MRI scans and encephalopathy may develop at high blood bismuth concentrations > 100µg/L but this is usually reversible on cessation of therapy. Bismuth accumulates in the kidney as the metallothionein complex
Laboratory Indices of Exposure
Concentrations of bismuth in blood and urine can be measured. Rapid renal clearance maintains low circulating concentrations of bismuth so that clinical and biochemical abnormalities are more likely with renal insufficiency.
References:
Hall DWR. Review of the mode of action of colloidal bismuth subcitrate. Scand J Gastroenterol 1989; 24(suppl 157): 3-6
Anon. Bismuth and dyspesia. Lancet 1990; 336: 472-3
Wilson APR. The dangers of BIPP (bismuth iodoform paraffin paste). Lancet 1994; 344: 1313-4