[Biotransformation of Chlorphenethazin (Elroquil, Marophen)]

After application of chlorophenethazine more than 20 metabolites were detected in rat urine. The structure of 14 metabolites were elucidated (UV, MS), which are hydroxy, N-dealkyl, S-oxide, sulfone and N-oxid derivatives. The hydroxy derivatives are partly conjugated. The relative high content of the sulfone of 2-chlorophenothiazine-N-acetic acid (upto 10% of the total metabolite content) is remarkable. Main metabolites are the S-oxide of the N-dealkyl derivative and 7-hydroxy-1.