Serotonin Antagonists and Serotonin Reuptake Inhibitors (SIAs)

This type of drugs can be used in patients with depression and other mental disorders.

Among all mental problems, depression is, together with anxiety-related disorders, one of the most common worldwide. 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, different therapeutic alternatives have been generated and synthesized, and there are currently a large number of substances that help to alleviate both depression and other problems. One of the types of drugs synthesized is extremely interesting since it works in an apparently opposite way to other drugs. It is the Serotonin Reuptake Antagonists and Inhibitors or AIRSs.

Serotonin Antagonists and Serotonin Reuptake Inhibitors: what are they?

Serotonin Antagonists and Serotonin Reuptake Inhibitors or SARIs (Serotonin Antagonist and Reuptake Inhibitors) are a type of atypical and relatively novel Antidepressant characterized by characterized by an unusual mechanism of action and apparently contrary to the way other antidepressants work.

On the one hand, they inhibit the reuptake of serotonin, which increases its levels in the brain, but on the other hand, they exert opposite effects on certain serotonin receptors, which in principle reduces the presence and action of this neurotransmitter.

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

However, in spite of their atypical functioning, this group of drugs have proven useful for the treatment of depressive symptomatology, as well as for other mental conditions and problems. as well as for other mental conditions and problems.

Mechanism of action.

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

The AIRSs have a dual mechanism of actionThey mainly generate two types of changes in brain chemistry.

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

On the other hand, the action of this type of drug has an antagonistic effect on the presynaptic receptors. an antagonistic effect on the 5HT2A and 5HT2C receptors, preventing serotonin from being used by postsynaptic neurons.receptors, preventing serotonin from acting on them. In the 5HT1A receptors, however, the effect is agonistic, facilitating effects similar to those of serotonin.

It is this last mechanism of action that makes the way of acting of AIRS somewhat different and peculiar if we compare it with other types of antidepressant more known, possessing anxiolytic and hypnotic properties.

Therapeutic indications of AIRS

Serotonin reuptake antagonists and inhibitors are substances classified as antidepressants, so their main indication is the treatment of depression. their main indication is the treatment of major depression..

These drugs also have anxiolytic action, making them effective in the treatment of various anxiety-related conditions. Thus, they have been used (specifically with regard to 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 a hypnotic and sedative effect. hypnotic and sedative effect.. This effect has also been used in some cases of bipolar disorder or psychotic disorders such as schizophrenia.

Side effects.

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

There may also be a risk of suicidal ideation appearing more easily in the first weeks, something common to many antidepressants. Priapism and arrhythmias may also appear and have consequences in people with previous cardiovascular problems.

It should be noted that the main representative of these drugs is excreted in breast milk, so it is contraindicated in pregnant and lactating women. Also in people with cardiac problems and previous heart attacks and hepatic or renal problems. Special caution should be taken in cases of bipolar or psychotic disorder, since it may favor a shift to manic symptoms or the appearance of positive symptoms such as hallucinations and agitation.