Disposition of bismuth in the rat. II. Pharmacokinetics and biliary excretion.

The pharmacokinetics and biliary excretion profile of intravenously administered bismuth ions were investigated in male Sprague Dawley rats. The data indicated that in the dose range studied, the percentage of dose excreted in urine ranged from 58 to 63%. The mean residence time for bismuth ions was 3.93, 4.07, and 5.45 hr for the 0.5, 0.75, and 1.0 mg/kg dose, respectively, while the volume of distribution at steady state was 0.75, 1.24, and 1.38 L/kg for the three doses. Blood clearance values ranged from 0.2 to 0.32 L/hr/kg. Blood bismuth ion concentrations toward the latter part of the sampling schedule indicated significant variability. The bile-to-blood concentration ratio of intravenously administered bismuth exceeded 1.0 for the three doses studied, suggesting that transport of bismuth from blood to bile may be carrier mediated.