Absorption - Oral Bismuth (Bi)


  • The more soluble compounds, e.g. bismuth subnitrate, are more readily absorbed.

  • Citrate enhances absorption.

  • Many bismuth salts are poorly absorbed due to their insolubility. It has been suggested that oral Bi absorption depends on the solubility of the Bi compound in the GI tract (Billon et al., 1976; Thomas and al, 1977; Thomas et al., 1983; Lechat and Kisch, 1986).

  • Pharmacologically active Bi salts were divided into four groups:

    1. Water insoluble organic salts and sub-salts that are minimally absorbed, and therefore cause no toxicity.

    2. Lipid-soluble organic compounds which are sufficiently absorbed to elevate Bi blood levels and cause neurotoxicity and hepatotoxicity.

    3. Water-soluble compounds which are sufficiently absorbed to elevate Bi blood levels and cause nephrotoxicity.

    4. Water-soluble complexes that hydrolyze in the GI tract resulting in some absorption of Bi and the hydrolyzed radical, elevating blood levels of Bi and the complex radical (Slikkerveer and de Wolff, 1989).

  • Bi bioavailability, using 205Bi, was studied in rats. Bioavailability of the citrate containing compounds (colloidal Bi subcitrate, soluble Bi citrate, and basic Bi citrate) was significantly higher (0.26-0.33%) than from basic Bi nitrate, Bi salicylate, Bi gallate and Bi aluminate (0.04-0.11%) (Dresow et al., 1991). Intestinal perfusion of rat small intestine with Bi citrate and colloidal Bi subcitrate resulted in higher Bi concentrations in the blood than with Bi subnitrate, Bi subsalicylate or Bi chloride (Slikkerveer et al., 1995).

  • Bi bioavailability from 205Bi-labeled compounds given to human volunteers showed the same trends as in rats, but lower bioavailability: 0.042% of colloidal bismuth subcitrate, 0.038% of basic bismuth gallate, and 0.002 to 0.005% of basic Bi nitrate, basic Bi subsalicylate, and Bi aluminate appeared in the urine (Dresow et al., 1992).

  • Although the Bi species that is absorbed from the intestine is unknown, the absorbed species is usually not the species that was ingested. Several unidentified Bi species may form in the intestine, in which the counter-ion has been suggested to be responsible for absorption.

  • Simultaneous intraperitoneal cysteine and Bi subnitrate administration increased Bi absorption (Chaleil et al., 1979). Sulfhydryl-group-containing compounds increased the Bi blood concentration in rats. Cysteine, homocysteine, 3-mercaptopropionic acid and penicillamine produced the greatest increase. Methionine, serine and alanine did not increase the Bi blood concentration (Chaleil et al., 1981). Cysteine increased Bi absorption from Bi subsalicylate in rats. This was not seen when cysteine was simultaneously given with the Bi salt in a cysteine-rich diet (D'Souza and Francis, 1987).

  • Citrate increased intestinal absorption of Bi from Bi subnitrate, Bi subsalicylate, Bi citrate, Bi chloride, and collodial Bi subcitrate given by in vivo perfusion of the rat small intestine (Slikkerveer et al., 1992a). The citrate-enhanced absorption of Bi was reduced by active and passive transport blockers, suggesting Bi absorption by both transcellular and paracellular routes (Slikkerveer et al., 1992a).

  • Simultaneous citrate intake with Bi subnitrate by human volunteers significantly increased Bi absorption. The absorption profiles for Bi in blood and citrate in serum were parallel, suggesting formation and absorption of a Bi citrate complex (Slikkerveer et al., 1992b).

  • The site(s) of Bi absorption are unknown (Slikkerveer and de Wolff, 1996). The bioavailability of radiolabeled Bi compounds corresponded with their solubility in artificial duodenal, but not gastric, juice (Dresow et al., 1991).

Link to Absorption Periodic Table

Link to Database Index


Comments to Robert Yokel, Ph.D., Last Modified: November 17, 2008
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