ChEBI: Amitriptyline is an organic tricyclic compound that is 10,11-dihydro-5H-dibenzo[a,d][7]annulene substituted by a 3-(dimethylamino)propylidene group at position 5. It has a role as an adrenergic uptake inhibitor, an antidepressant, an environmental contaminant, a xenobiotic and a tropomyosin-related kinase B receptor agonist. It is a tertiary amine and an organic tricyclic compound. It derives from a hydride of a dibenzo[a,d][7]annulene.NCI Thesaurus (NCIt): Amitriptyline is a derivative of dibenzocycloheptadiene and a tricyclic antidepressant. Amitriptyline inhibits the re-uptake of norepinephrine and serotonin by the presynaptic neuronal membrane in the central nervous system (CNS), thereby increasing the synaptic concentration of norepinephrine and serotonin. Due to constant stimulation to these receptors, amitriptyline may produce a downregulation of adrenergic and serotonin receptors, which may contribute to the antidepressant activity.