Amitriptylinoxide (Amioxid, Ambivalon, Equilibrin), or amitriptyline N-oxide, is a tricyclic antidepressant (TCA) which was introduced in Europe in the 1970s for the treatment of depression.[1]

Amitriptylinoxide is both an analogue and metabolite of amitriptyline, and has similar effects as well as equivalent efficacy as an antidepressant.[2][3][4][5] However, it has a faster onset of action and fewer adverse effects, including reduced drowsiness, sedation, anticholinergic symptoms like dry mouth, sweating, and dizziness, orthostatic hypotension, and cardiotoxicity.[2][3][3][4][5][6]

In receptor binding assays, amitripylinoxide was found to have generally equivalent pharmacology to amitriptyline, acting as a serotonin and norepinephrine reuptake inhibitor, serotonin receptor antagonist, and H1 receptor antagonist, among other properties, but with approximately 60-fold lower affinity for the α1-adrenergic receptor, and the weakest affinity of any of the TCAs analyzed for the muscarinic acetylcholine receptors.[3][7][8]

See also