[On the metabolism of eprazinone (author's transl)].

After oral application of 3-[4-(beta-ethoxyphenethyl)-1-piperazinyl]-2-methylpropiophenone dihydrochloride (eprazinone, Eftapan) together with the unchanged drug, five degradation products were detected and subsequently identified by gas liquid chromatography/mass spectrometry in human urine. With respect to the presented results, eprazinone is degraded by various routes in man: 1. hydrolysis which leads to metabolites M1 and M4, and 2. cleavage of alpha-binding to the nitrogen atom and successive dealkylation reactions resulting in M2, M3 and M5, respectively.