Tricyclic antidepressant

Tricyclic antidepressant
Drug class
Chemical structure of the prototypical and first marketed tricyclic antidepressant imipramine showing its three rings.
Class identifiers
Chemical class	Tricyclic
External links
MeSH	D000929
Legal status
In Wikidata

Tricyclic antidepressants (TCAs) are a class of medications that are used primarily as antidepressants. TCAs were discovered in the early 1950s and were marketed later in the decade.^[1] They are named after their chemical structure, which contains three rings of atoms. Tetracyclic antidepressants (TeCAs), which contain four rings of atoms, are a closely related group of antidepressant compounds.

Although TCAs are sometimes prescribed for depressive disorders, they have been largely replaced in clinical use in most parts of the world by newer antidepressants such as selective serotonin reuptake inhibitors (SSRIs), serotonin–norepinephrine reuptake inhibitors (SNRIs) and norepinephrine reuptake inhibitors (NRIs). Adverse effects have been found to be of a similar level between TCAs and SSRIs.^[2]