Investigation of the metabolites of tofizopam in man and animals by gas-liquid chromatography-mass spectrometry.

The metabolites of tofizopam [Grandaxin; 1-(3,4-dimethoxyphenyl)-4-methyl-5-ethyl-7,8-dimethoxy-5H-2,3-benzodiazepine] have been studied in patients and animals. The major pathway of the metabolic transformation of tofizopam was found to be demethylation. The position in which demethylation takes place and the rate of this process in various species were determined. Gas-liquid chromatography-mass spectrometry-mass chromatography was used for the identification of the metabolites.