Metabolism of trimipramine in man

This paper describes studies on the metabolism of the tricyclic antidepressant 5-(3-dimethylamino-2-methylpropyl)-10,11-dihydro-5H-dibenz[b,f]azepine (trimipramine, Stangyl) in man. The metabolites were identified after cleavage of conjugates, extraction and derivatisation by acetylation in human urine using gas chromatography-mass spectrometry. Besides the unchanged trimipramine (T), the following 15 metabolites could be identified: mono- and dihydroxy-T, hydroxy-methoxy-T; iminodibenzyl (I), mono- and dihydroxy-I, hydroxy-methoxy-I; nor-T (NT), mono- and dihydroxy-NT, hydroxy-methoxy-NT; bis-nor-T (BNT), mono- and dihydroxy-BNT and hydroxy-methoxy-BNT. Therefore 3 overlapping metabolic pathways can be postulated: N-dealkylation of the nitrogen in the iminodibenzyl ring, 1- and 2-fold N-demethylation of the nitrogen in the side chain and 1- and 2-fold aromatic hydroxylation of the iminodibenzyl ring. The dihydroxy metabolites are partly methylated at one of the hydroxy groups. The hydroxy metabolites are conjugated additionally.