Ioglycamide (Biligram) studies in man--plasma binding, renal and biliary excretion studies in jaundiced and anicteric patients.

When five patients with varying degrees of hepatic impairment and a T-tube in situ were given intravenous ioglycamide at a rate of 2 mg/kg/min for two hours the mean biliary excretion in the first two hours was only 3.2% of the administered dose. In contrast, in five T-tube patients with relatively normal liver function the mean biliary excretion over the same time interval was 20.6%. The mean plasma concentration of ioglycamide achieved at the end of a two-hour intravenous infusion at 2 mg/kg/min was 1427 +/- 187 microgram/ml in six anicteric patients and 1262 +/- 82 in six jaundiced patients. Despite these very similar plasma levels the 24-hour urinary excretion of ioglycamide was 42.3 +/- 3.8% of the administered dose in the patients with jaundice compared with only 18.1 +/- 2.4% in the anicteric group. These differences probably reflect the fact that the percentage of unbound contrast agent in the plasma of the jaundiced group (11.9 +/- 1.9%) was significantly higher than that of the anicteric group (6.4 +/- 0.9%). It is suggested that bilirubin and possibly other substances in the plasma are competing with ioglycamide for binding sites on albumin. These factors need to be borne in mind when performing intravenous cholangiograms on jaundiced patients.

A simple spectrophotometric method for measuring biliary ioglycamide (Biligram) concentration.

An extremely simple spectrophotometric method for measuring biliary ioglycamide (meglumine ioglycamate) concentration is described. It was validated by a radioactive technique.

Prolonged drip-infusion cholangiography.

Previous experimenttal work in animals has shown that the hpatic excretion of iodipamide and ioglycamide is subject to a transport maximum (TM). Doses in excess of this TM are largely excreted in the urine. In the present study the TM for man was estimated in three subjects with indwelling T-tubes: figures of 19-23 mg/minute for ioglycamide were obtained. It was thought that prolonged administration of contrast at levels slightly above the TM might have advantages in patients with impaired liver function. In obstruction the gradual excretion of contrast could improve the chances of filling the ducts completely, while in hepato-cellular disease the gall bladder might have time to concentrate the contrast. Ioglycamide was therefore given by slow overnight infusion, equivalent to 35 mg/minute, to patients in whom standard cholangiography had been unsuccessful. The overall success rate was 75 per cent with similar improvement in obstructive and hepatocellular disease.