Tricyclic Antidepressants

Also known as:  Tricyclics

Tricyclic Antidepressants are a group of Pharmaceutical Antidepressants.  They operate (primarily) by blocking the reuptake of Norepinephrine into Neurons, thereby increasing the effects of Norepinephrine (Tricyclic Antidepressants could therefore be described as Norepinephrine Reuptake Inhibitors).  Chemically, Tricyclic Antidepressants consist of 3 Benzene rings.

Nervous System

 Tricyclic Antidepressants are commonly prescribed by physicians for the treatment of Depression:

 Many Tricyclic Antidepressants increase Dopamine levels within the Brain by blocking the reuptake of Norepinephrine into Dopamine D2 Receptors (i.e. by functioning as Dopamine Reuptake Inhibitors).

 Many Tricyclic Antidepressants increase Histamine levels within the Brain by blocking the reuptake of Histamine into Histamine H2 Receptors (i.e. by functioning as Histamine Reuptake Inhibitors).

 TCAs bind to and block Histamine H1 Receptors within the Brain - different types of TCAs have differing degrees of affinity for Histamine H1 Receptors.

 Many Tricyclic Antidepressants increase Norepinephrine levels within the Brain by blocking the reuptake of Norepinephrine into Alpha-1 Adrenergic Receptors (i.e. by functioning as Norepinephrine Reuptake Inhibitors).