Dothiepin HCl is a Tricyclic antidepressant (TCA), acting as a serotonin–norepinephrine reuptake inhibitor (SNRI) and also having other activities including antihistamine, antiadrenergic, antiserotonergic, anticholinergic, and sodium channel-blocking effects.

Dothiepin-d6 HCl (N,N-dimethyl-d6) (cis/trans mixture) is a deuterated compound of Dothiepin HCl. Dothiepin HCl has a CAS number of 25627-36-5.

Dothiepin (Dosulepin; Dothep), an antidepressant with sedative/anxiolytic properties, preferentially inhibits noradrenaline over serotonin uptake, enhancing noradrenergic neurotransmission by blocking neuronal reuptake. Additionally, it acts as a histamine H1-receptor antagonist and lacks cardiotoxicity. Its analgesic efficacy is noted in conditions such as psychogenic facial pain, idiopathic fibromyalgia syndrome, and rheumatoid arthritis [1].