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The biliary and urinary excretion and the choleretic effect of ioglycamide were studied in unanesthetized bile fistula dogs using stepwise increasing infusion rates to obtain multiple steady states. The results are compared with data from previously reported experiments in the same animals using iodoxamate and iodipamide. The rate of biliary excretion and the choleretic effect of ioglycamide are similar to those of iodipamide and iodoxamate. Like iodipamide and iodoxamate, the relation between infusion rate or plasma concentration and biliary excretion or concentration of ioglycamide are hyperbolic and can be fitted to saturation kinetics. Quantitatively, the excretion of ioglycamide and iodipamide are virtually identical. However, for any equimolar infusion rate or plasma concentration, more iodoxamate than ioglycamide is excreted in the bile. Despite the greater biliary excretion of iodoxamate, the maximum biliary concentration of ioglycamide, iodipamide, and iodoxamate is the same at low basal bile flow because the choleretic effects of the three compounds are equal. The data suggest that, theoretically, with any equimolar dose ioglycamide will be identical to iodipamide as a contrast material for intravenous cholangiography, but that iodoxamate may be superior to ioglycamide because more iodoxamate is excreted in the bile. This advantage of iodoxamate might become apparent clinically in patients with high basal bile flow or if smaller doses of the contrast material are used. However, at the presently recommended doses of the two compounds, it is unlikely that the use of ioglycamide for intravenous cholangiography will be any different than iodoxamate.

The biliary and urinary excretion of sodium tyropanoate (Bilopaque) and sodium ipodate (Oragrafin) were studied in unanesthetized bile-fistula dogs using stepwise, increasing, intravenous infusions of the contrast materials. A constant intravenous infusion of sodium taurocholate was administered at the rate of either 0.5 or 2.0 mu moles per min per kg throughout each experiment. The biliary excretion of sodium tyropanoate or sodium ipodate was not effected by the rate of sodium taurocholate infusion. The maximum rate of biliary excretion of sodium ipodate was significantly greater than that of sodium tyropanoate with the low taurocholate infusion, but there was no significant difference between the two with the high taurocholate infusion. With the low taurocholate infusion the maximum biliary excretion rate of sodium tyropanoate (0.956 mu moles per min per kg) and sodium ipodate (1.472 mu moles per min per kg) were significantly greater than the maximum biliary excretion of iopanoic acid (Telepaque) (0.671 mu moles per min per kg). With the high taurocholate infusion the maximum biliary excretion rates of the three contrast agents were not statistically different. Both sodium tyropanoate and sodium ipodate produced an increase in canalicular bile flow (8-11 ml per millimole). These data suggest that in clinical cholecystography sodium tyropanoate and sodium ipodate are not excreted in bile more rapidly than iopanoic acid, except when the rate of biliary excretion of bile salts is low; that is, except in patients who are fasting or those who are on a fat-free diet.

Biliary tract disease is a major cause of acute pancreatitis. However, with traditionally employed Telepaque, radiographic visualization of the gallbladder during acute pancreatitis remains unreliable, even in patients with apparently normal gallbladders. Therefore, oral cholecystography has customarily been deferred for such patients for several weeks. Recently, successful oral cholecystography has been described during the acute episode of pancreatitis, using Bilopaque, a more water-soluble cholecystopaque. The relative intestinal absorption of Telepaque and Bilopaque and the ability of these agents to produce diagnostic oral cholecystograms of fasting patients with acute alcoholic pancreatitis were compared. Forty-five hospitalized patients were studied within 96 hours of admission. Mean peak plasma contrast concentrations for Bilopaque exceeded those for Telepaque. Thirty-one percent of the Bilopaque group achieved diagnostic single-dose oral cholecystograms, compared with to 11% of the Telepaque group (P less than 0.05).

The biliary excretion of two oral cholecystographic contrast agents, iocetamic acid and iopanoic acid, were compared during low and high taurocholate infusion rates. The pharmacokinetics of these compounds after intravenous infusion were studied in bile-fistula dogs using both indirect and direct pharmacokinetic techniques. The indirect multiple infusion technique, corrected for urinary excretion, provides a reliable estimate of the maximum biliary excretion rates of either contrast agent without necessitating the sampling of biliary output. The results indicate that taurocholate facilitates the biliary excretion of both agents. At both taurocholate infusion rates studied, the maximum biliary excretion rate of iocetamic acid is greater than that of iopanoic acid.