Doxepin hydrochlorideProduct ingredient for Doxepin

Doxepin is a psychotropic agent with antidepressant and anxiolytic properties.⁹ It is a tertiary amine that can be presented as (E) and (Z) stereoisomers with the (Z) stereoisomer corresponding to cidoxepin. Doxepin commonly produces a 5:1 (E):(Z) racemic mixture.⁸

In a strict sense, doxepin is not a tricyclic antidepressant but it is commonly associated with the class since it shares a lot of properties with members of the drug family including amitriptyline, clomipramine, desipramine, imipramine, nortriptyline, protriptyline and trimipramine.¹³

Doxepin was developed by Pfizer and FDA approved in 1969 as an antidepressant.¹¹ However, in 2010 it was approved for the treatment of insomnia. The latter indication was presented by Pernix Therapeutics.¹²