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Antagonists and Inhibitors of Serotonin Reuptake (AIRSs)

Antagonists and Inhibitors of Serotonin Reuptake (AIRSs)

March 28, 2024

Among all mental problems, depression is one of the most common disorders in the world together with anxiety disorders. The treatment of this type of problem has been something that has generated extensive research from multiple scientific disciplines, one of them being psychopharmacology.

From this discipline they have been generating and synthesizing different therapeutic alternatives, existing at the present time a great amount of substances that contribute to mitigate both the depression and other problems. One of the types of drugs synthesized is extremely interesting because it works in a way apparently contrary to other drugs. Is about Antagonists and Inhibitors of Reuptake of Serotonin or AIRSs .


  • Related article: "Types of antidepressants: characteristics and effects"

Antagonists and Inhibitors of Serotonin Reuptake: what are they?

Antagonists and Inhibitors of Serotonin Reuptake or AIRSs (Serotonin Antagonist and Reuptake Inhibitor or SARIs in English) are a type of atypical antidepressant and relatively new characterized by having an unusual mechanism of action and apparently contrary to the way other antidepressants work.

On the one hand, they inhibit the reuptake of serotonin with which their levels at the brain level increase, but on the other they exert opposite effects to it in certain receptors of the same, which in principle reduces the presence and action of this neurotransmitter.


The main and best known representative of this type of drugs is trazodone , a drug with therapeutic success in both depression and other anxious features. Other substances such as nefazodone also have characteristics and mechanisms of action of this type of drugs, although since it also acts to a large extent in other neurotransmitters, they do not fall into this classification.

However, despite its atypical functioning, this group of drugs have been shown to be useful for the treatment of depressive symptoms as well as for other conditions and mental problems.

  • Maybe you're interested: "Types of psychotropic drugs: uses and side effects"

Mechanism of action

As mentioned above, antagonists and inhibitors of serotonin reuptake have a mechanism of action of differentiated action in relation to other similar drugs.


The AIRSs they have a dual action mechanism , generating mainly two types of change in brain chemistry.

On the one hand, they are characterized by generating a blockade in the reuptake of serotonin in presynaptic neurons , which makes this neurotransmitter more present in the synaptic space and can be used by postsynaptic neurons.

On the other, the action of this type of drug has an antagonistic effect on 5HT2A and 5HT2C receptors , preventing serotonin from acting on them. Of course, in 5HT1A receptors the effect is agonist, facilitating effects similar to those of serotonin.

It is this latter mechanism of action that makes AIRs' way of acting somewhat different and peculiar when compared to other types of antidepressants that are better known, with anxiolytic and hypnotic properties.

Therapeutic indications of AIRSs

Antagonists and inhibitors of serotonin reuptake are substances classified as antidepressants, thereby Its main indication is the treatment of her major depression .

Also these drugs have anxiolytic action, which are also effective for the treatment of various conditions linked to anxiety. Thus, they have been used (specifically as regards trazodone) in problems such as generalized anxiety, erectile dysfunction of psychogenic origin, bulimia nervosa, OCD, or withdrawal syndromes.

They are also used in sleep problems, such as insomnia, because they have hypnotic and sedative effect . This effect has also been used in some cases of bipolar disorder or in psychotic disorders such as schizophrenia.

  • You may be interested: "Major depression: symptoms, causes and treatment"

Side effects

Like all psychotropic drugs, AIRSs can have different side effects. Nausea and vomiting are frequent (especially in the first weeks), sedation and fatigue, fatigue, hypotension, edema or blurred vision.

There may also be a risk that suicidal ideation, which is common to many antidepressants, will appear more easily in the first weeks.Priapism and arrhythmias can also appear and have consequences in people with previous cardiovascular problems.

It must be taken into account that the main representative of these drugs is excreted with breast milk, which is contraindicated in pregnant women and infants. Also in people with heart problems and previous heart attacks and liver or kidney problems. Special caution should be used in cases of bipolarity or psychotic disorder, since it may favor a shift to manic symptoms or the appearance of positive symptoms such as hallucinations and agitation.

Bibliographic references:

  • Alcántara-López, M.G .; Gutiérrez-García, A.G .; Hernández-Lozano, M. & Contreras, C.M. (2009). Trazodone, an atypical antidepressant with anxiolytic and sedative properties. Arch. Neurocien (Mex), 14 (4): 249-257.
  • Pérez, R. (2017). Pharmacological treatment of depression: news and future directions. Rev. Fac. Med. (Méx.), 60 (5). Mexico City.

2-Minute Neuroscience: Selective Serotonin Reuptake Inhibitors (SSRIs) (March 2024).


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