Quantitative Aspects of the Urinary Excretion of Meptazinol and Its Metabolites in Human Volunteers

Abstract

1. The urinary excretion of meptazinol and its metabolites has been studied in five healthy human volunteers following oral administration of 200 mg of the ³H-labelled drug.

2. Meptazinol was well absorbed, with 90% of the radioactivity excreted in the urine; elimination of drug-related material took place rapidly.

3. Metabolism was extensive, no unchanged material being detected in the urine. Following selective enzymic hydrolysis the major metabolites were identified as glucuronide and sulphate conjugates of the parent drug present in an approximate ratio of 4:1.

4. A number of minor metabolites, also present in conjugated form, were tentatively identified.