Metabolism of amineptine in rat, dog and man

After oral administration of amineptine (7-[(10-11)-dihydro-5H-dibenzo(a,d)cycloheptane-5yl] amino heptanoic acid), an original tricyclic antidepressant, seven metabolites were isolated from urine and plasma of rat, dog and man. The metabolic pathways were similar for the three species studied. The two major pathways consisted of the beta-oxidation of the heptanoic side chain leading to pentanoic (first step) and propanoic (second step) side chain metabolites and the hydroxylation of the dibenzocycloheptyl ring on carbon atom 10 (C10) causing the formation of two diastereoisomers. Lactamization by internal dehydration of beta-oxidized metabolites appeared to be a minor route of biotransformation. Conjugation reactions were of minor importance in the rat, in contrast to findings for dog and man. Urinary elimination was the major route of excretion in man while in dog and in rat faecal excretion was predominant.