Tetracyclic antidepressant

Tetracyclic antidepressants (TeCAs) are a class of antidepressants that were first introduced in the 1970s. They are named after their tetracyclic chemical structure, containing four rings of atoms, and are closely related to the tricyclic antidepressants (TCAs), which contain three rings of atoms. Maprotiline (Ludiomil) – can also be classified as a TCA and grouped with the secondary amines Mianserin (Tolvon) Mirtazapine (Remeron) Setiptiline (Tecipul) Drugs that contain four rings not all fused together but are sometimes still classified as TeCAs include: Amoxapine (Asendin) – often classified as a TCA and grouped with the secondary amines Quetiapine (Seroquel) - an atypical antipsychotic sometimes used as an adjunct antidepressant Benzoctamine (Tacitin) – a tetracyclic compound and is closely related to maprotiline, with the two compounds differing only in the length of their side chain, but benzoctamine is not used as an antidepressant and is instead used as an anxiolytic Loxapine (Adasuve, Loxitane) – a typical antipsychotic that produces amoxapine as a major metabolite and is said to have antidepressant effects, but it is not usually regarded as a TeCA Drugs that contain four rings not all fused together but could still be classified as tetracyclic include: Mazindol (Mazanor, Sanorex) – a monoamine reuptake inhibitor used as an appetite suppressant and with potential antidepressant effects, but not classified as a TeCA Aptazapine (CGS-7525A) – a close analogue of mirtazapine Esmirtazapine (ORG-50,081) – the (S)-(+) enantiomer of mirtazapine Oxaprotiline (C 49-802 BDA) – a close analogue of maprotiline Drugs that contain four rings not all fused together but could still be classified as tetracyclic include: Ciclazindol (WY-23,409) – a close analogue of mazindol Pharmacology of antidepressants TeCAs have diverse pharmacology and differ from TCAs in a number of ways. With the exception of amoxapine, TeCAs do not inhibit the reuptake of serotonin. However, aside from mirtazapine, they do inhibit the reuptake of norepinephrine.