The fate of intravenous [3H]glycopyrrolate in man

Abstract

Abstract Glycopyrrolate was labelled in one methyl group with tritium and its fate was studied in six patients with T-tube drainage by determining serum levels as well as the biliary and urinary excretion of radioactivity after intravenous injection. More than 90 % of the radioactivity had disappeared from serum in 5 min and after 30 min almost no radioactivity could be found. The highest radioactivity in bile was found in samples taken 30 or 60 min after the injection. However, measurable radioactivity was found in most cases after 48 h. The first urine samples (0–3 h) showed the greatest radioactivity, and in 48 h 85% of the total radioactivity was excreted into the urine. Paper chromatography showed that both in bile and in urine over 80% of the radioactivity corresponded to unchanged glycopyrrolate. That appreciable amounts of glycopyrrolate were excreted into the bile suggests that the spasmolysis achieved with glycopyrrolate could be based partly on a local action on the bile ducts.