Allosteric serotonin reuptake inhibitor

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Allosteric serotonin reuptake inhibitor is a type of selective serotonin reuptake inhibitor (SSRI). Currently only escitalopram, the S stereoisomer of the SSRI citalopram is included in this category. It is based on the observation that the R isomer of citalopram can decrease the potency and inhibit the effects of the S isomer, probably through an allosteric interaction between two distinct, non-overlapping binding sites for the two different isomers on the serotonin transporter. Escitalopram, thus, binds not only to the primary site, but also to the allosteric site. From known SSRIs also paroxetine has action to the allosteric site, about half potency of escitalopram. [1]

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<span class="mw-page-title-main">Paroxetine</span> SSRI antidepressant medication

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<span class="mw-page-title-main">Sertraline</span> Antidepressant (SSRI class) medication

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<span class="mw-page-title-main">Escitalopram</span> Antidepressant of the selective serotonin reuptake inhibitor (SSRI) class

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A serotonin reuptake inhibitor (SRI) is a type of drug which acts as a reuptake inhibitor of the neurotransmitter serotonin by blocking the action of the serotonin transporter (SERT). This in turn leads to increased extracellular concentrations of serotonin and, therefore, an increase in serotonergic neurotransmission. It is a type of monoamine reuptake inhibitor (MRI); other types of MRIs include dopamine reuptake inhibitors and norepinephrine reuptake inhibitors.

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<span class="mw-page-title-main">Reuptake inhibitor</span> Type of drug

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<span class="mw-page-title-main">Talopram</span> Chemical compound

Talopram, also known as phthalapromine, is a selective norepinephrine reuptake inhibitor (NRI) which was researched for the management of depression in the 1960s and 1970s but was never commercialized. Along with talsupram, talopram is structurally related to the selective serotonin reuptake inhibitor (SSRI) citalopram, as well as to melitracen:

In 1971, the company hired Klaus Bøgesø as a medicinal chemist. Over the years Bøgesø turned out to have a Midas touch at the game of drug hunting, creating more molecules that made it to the market than almost any other medicinal chemist in the field. The challenge facing him in 1971 following his recruitment was to produce a selective norepinephrine reuptake inhibitor. Like other companies at the time, Lundbeck had little interest in an SSRI. Bøgesø began from an accident in the laboratory. Trying to create a derivative of their norepinephrine reuptake inhibiting antidepressant melitracen, Lundbeck chemists accidentally produced a new chemical — a phenylphthalene. Against all the odds, just like melitracen, this was also a selective norepinephrine reuptake inhibitor. Two potential antidepressants came out of this — talopram and tasulopram, which were pressed into clinical trials. Both however turned out to be energizing, and in a number of cases there were suicide attempts. The fact that there were suicide attempts appeared to confirm another proposal of Paul Kielholz, that activating antidepressants might lead to suicide. Lundbeck's experience suggested that norepinephrine reuptake inhibitors were likely to lead to just this problem. Lundbeck retreated, scared. If norepinephrine reuptake inhibitors were likely to trigger suicide, the greatest hazard of an antidepressant, then Kielholz's view suggested that an SSRI would be less likely to lead to suicide. Bøgesø's job was to see whether the new series of drugs could be converted into a series of SSRIs. Following a lead from Carlsson on how to do this, he converted talopram into citalopram, the most selective serotonin reuptake inhibitor to come to the market.

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<span class="mw-page-title-main">Didesmethylcitalopram</span> Chemical compound

Didesmethylcitalopram is an active metabolite of the antidepressant drug citalopram (racemic). Didesmethylescitalopram is an active metabolite of the antidepressant escitalopram, the S-enantiomer of citalopram. Like citalopram and escitalopram, didesmethyl(es)citalopram functions as a selective serotonin reuptake inhibitor (SSRI), and is responsible for some of its parents' therapeutic benefits.

<span class="mw-page-title-main">Selective serotonin reuptake inhibitor</span> Class of antidepressant medication

Selective serotonin reuptake inhibitors (SSRIs) are a class of drugs that are typically used as antidepressants in the treatment of major depressive disorder, anxiety disorders, and other psychological conditions.

A monoamine reuptake inhibitor (MRI) is a drug that acts as a reuptake inhibitor of one or more of the three major monoamine neurotransmitters serotonin, norepinephrine, and dopamine by blocking the action of one or more of the respective monoamine transporters (MATs), which include the serotonin transporter (SERT), norepinephrine transporter (NET), and dopamine transporter (DAT). This in turn results in an increase in the synaptic concentrations of one or more of these neurotransmitters and therefore an increase in monoaminergic neurotransmission.

Selective serotonin reuptake inhibitors, or serotonin-specific re-uptake inhibitor (SSRIs), are a class of chemical compounds that have contributed to the major advances as antidepressants where they have revolutionised the treatment of depression and other psychiatric disorders. The SSRIs are therapeutically useful in the treatment of panic disorder (PD), posttraumatic stress disorder (PTSD), social anxiety disorder, obsessive-compulsive disorder (OCD), premenstrual dysphoric disorder (PMDD), and anorexia. There is also clinical evidence of SSRIs efficiency in the treatment of the negative symptoms of schizophrenia and their ability to prevent cardiovascular diseases.

References

  1. Mansari, Mostafa El; Wiborg, Ove; Mnie-Filali, Ouissame; Benturquia, Nadia; Sánchez, Connie; Haddjeri, Nasser (February 2007). "Allosteric modulation of the effect of escitalopram, paroxetine and fluoxetine: in-vitro and in-vivo studies". The International Journal of Neuropsychopharmacology. 10 (1): 31–40. doi: 10.1017/S1461145705006462 . ISSN   1461-1457. PMID   16448580.