Cyclic metabolites of etidocaine in humans

1. Three cyclic metabolites of etidocaine excreted in urine of man have been investigated by g.l.c.-mass spectrometry. 2. These metabolites have been identified as 3-(2,6-dimethylphenyl)-5-ethyl-2,4-imidazolidinedione, 1-(2,6-dimethylphenyl)-2-methyl-4-ethyl-2-imidazolin-5-one and 1-(2,6-dimethylphenyl)-2,4-diethyl-2-imidazoline-5-one. 3. Formation in vivo of two of the metabolites is proposed to proceed via carbinolamine intermediates.