Noradrenergic and specific serotonergic antidepressant explained

Noradrenergic and specific serotonergic antidepressants (NaSSAs) are a class of psychiatric drugs used primarily as antidepressants.^[1] They act by antagonizing the α₂-adrenergic receptor and certain serotonin receptors such as 5-HT_2A and 5-HT_2C, but also 5-HT₃, 5-HT₆, and/or 5-HT₇ in some cases. By blocking α₂-adrenergic autoreceptors and heteroreceptors, NaSSAs enhance adrenergic and serotonergic neurotransmission in the brain involved in mood regulation, notably 5-HT_1A-mediated transmission.^[2] In addition, due to their blockade of certain serotonin receptors, serotonergic neurotransmission is not facilitated in unwanted areas, which prevents the incidence of many side effects often associated with selective serotonin reuptake inhibitor (SSRI) antidepressants;^[3] hence, in part, the "specific serotonergic" label of NaSSAs.

List of NaSSAs

The NaSSAs include the following agents:

• Aptazapine (CGS-7525A)
• Esmirtazapine (ORG-50,081)
• Mianserin (Bolvidon, Norval, Tolvon)^[4]
• Mirtazapine (Norset, Remeron, Avanza, Zispin)
• Setiptiline/teciptiline (Tecipul)

Notably, all of these compounds are analogues and are also classified as tetracyclic antidepressants (TeCAs) based on their chemical structures.

S32212, a structurally novel NaSSA with an improved selectivity profile (e.g., no antihistamine effects, etc.), was reported in 2012.^{[5] [6]} It has completed preliminary preclinical research and may go on to undergo clinical trials.

See also

• Serotonin antagonist and reuptake inhibitor (SARI)
• Serotonin modulator and stimulator (SMS)
• Norepinephrine-dopamine disinhibitor (NDDI)
• Tetracyclic antidepressant
• Norepinephrine–dopamine reuptake inhibitor
• Atypical antidepressant

Further reading

• Kent JM . SNaRIs, NaSSAs, and NaRIs: new agents for the treatment of depression . Lancet . 355 . 9207 . 911–8 . March 2000 . 10752718 . 10.1016/S0140-6736(99)11381-3 . 27686300 . free .

Notes and References

1. Book: Robert M. Julien . A Primer Of Drug Action: A Comprehensive Guide To The Actions, Uses, And Side Effects Of Psychoactive Drugs . 23 April 2012 . 17 September 2004 . Macmillan . 978-0-7167-0615-1 . 286.
2. Book: Robert E. Hales . Narriman C. Shahrokh . Alan F. Schatzberg . Charles B. Nemeroff . Study Guide to Psychopharmacology: A Companion to the American Psychiatric Publishing Textbook of Psychopharmacology, Fourth Edition . 23 April 2012 . 28 April 2009 . American Psychiatric Pub . 978-1-58562-354-9 . 202.
3. Book: Bentham Science Publishers . Current Pharmaceutical Design . 23 April 2012 . August 1998 . Bentham Science Publishers . 298.
4. Book: Roland A. Carlstedt . Handbook of Integrative Clinical Psychology, Psychiatry, and Behavioral Medicine: Perspectives, Practices, and Research . 23 April 2012 . 14 December 2009 . Springer Publishing Company . 978-0-8261-1094-7 . 290.
5. Millan MJ, Mannoury la Cour C, Chanrion B, etal . S32212, a novel serotonin type 2C receptor inverse agonist/α2-adrenoceptor antagonist and potential antidepressant: I. A mechanistic characterization . The Journal of Pharmacology and Experimental Therapeutics . 340 . 3 . 750–64 . March 2012 . 22178752 . 10.1124/jpet.111.187468 . 8546314 .
6. Dekeyne A, Brocco M, Loiseau F, etal . S32212, a novel serotonin type 2C receptor inverse agonist/α2-adrenoceptor antagonist and potential antidepressant: II. A behavioral, neurochemical, and electrophysiological characterization . The Journal of Pharmacology and Experimental Therapeutics . 340 . 3 . 765–80 . March 2012 . 22178753 . 10.1124/jpet.111.187534 . 11363664 .