Identification of phenprocoumon metabolites in human urine by high-performance liquid chromatography and gas chromatography-mass spectrometry.

The oral anticoagulant phenprocoumon is eliminated in urine mainly as the glucuronide conjugate to an extent of 20% of the dose. The urine from patients undergoing phenprocoumon therapy was investigated and the following metabolites were isolated and identified: 7-hydroxyphenprocoumon as the main component, and 4'-hydroxyphenprocoumon and 6-hydroxyphenprocoumon as conjugates. They were characterized by high-performance liquid chromatography and, after methylation, by gas chromatography-mass spectrometry.