A serotonin modulator and stimulator (SMS), sometimes referred to more simply as a serotonin modulator, is a type of
drug
A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via insufflation (medicine), inhalation, drug i ...
with a multimodal action specific to the
serotonin
Serotonin (), also known as 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter with a wide range of functions in both the central nervous system (CNS) and also peripheral tissues. It is involved in mood, cognition, reward, learning, ...
neurotransmitter
A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a Chemical synapse, synapse. The cell receiving the signal, or target cell, may be another neuron, but could also be a gland or muscle cell.
Neurotra ...
system. To be precise, SMSs simultaneously modulate one or more
serotonin receptor
5-HT receptors, 5-hydroxytryptamine receptors, or serotonin receptors, are a group of G protein-coupled receptor and ligand-gated ion channels found in multiple tissues including the central and peripheral nervous systems. They mediate both ex ...
s and inhibit the
reuptake
Reuptake is the reabsorption of a neurotransmitter by a neurotransmitter transporter located along the plasma membrane of an axon terminal (i.e., the pre-synaptic neuron at a synapse) or glial cell after it has performed its function of transmi ...
of serotonin. The term was created to describe the
mechanism of action
In pharmacology, the term mechanism of action (MOA) refers to the specific biochemical Drug interaction, interaction through which a Medication, drug substance produces its pharmacological effect. A mechanism of action usually includes mention o ...
of the serotonergic
antidepressant
Antidepressants are a class of medications used to treat major depressive disorder, anxiety disorders, chronic pain, and addiction.
Common side effects of antidepressants include Xerostomia, dry mouth, weight gain, dizziness, headaches, akathi ...
vortioxetine
Vortioxetine, sold under the brand name Trintellix (in the US) and Brintellix (in the EU) among others, is an antidepressant medication of the serotonin modulator and stimulator (SMS) class used in the treatment of major depressive disorder. ...
, which acts as a
serotonin reuptake inhibitor
A serotonin reuptake inhibitor (SRI) is a type of drug which acts as a reuptake inhibitor of the neurotransmitter serotonin (5-hydroxytryptamine, or 5-HT) by blocking the drug action, action of the serotonin transporter (SERT). This in turn lea ...
(SRI),
agonist
An agonist is a chemical that activates a Receptor (biochemistry), receptor to produce a biological response. Receptors are Cell (biology), cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an R ...
antagonist
An antagonist is a character in a story who is presented as the main enemy or rival of the protagonist and is often depicted as a villain.5-HT3 and 5-HT7 receptors. However, it can also technically be applied to
vilazodone
Vilazodone, sold under the brand name Viibryd among others, is a medication used to treat major depressive disorder. It is classified as a serotonin modulator and is taken by mouth.
Common side effects include nausea, diarrhea, and trouble ...
, which is an antidepressant as well and acts as an SRI and 5-HT1A receptor partial agonist.
SMSs were developed because there are many different subtypes of serotonin receptors (at least 15 in total are currently known) and not all of these receptors appear to be involved in the antidepressant effects of SRIs. Some serotonin receptors seem to play a relatively neutral or insignificant role in the regulation of mood, but others, such as 5-HT1A autoreceptors and 5-HT7 receptors, appear to play an oppositional role in the efficacy of SRIs in treating depression. As such, a drug which combines the actions of, say, an SRI, 5-HT1A partial agonism, and 5-HT7 receptor antagonism, could, in theory, have the potential to prove more effective than pure SRIs. Alternatively, antagonism of 5-HT3 – a receptor that is involved in the regulation of
nausea
Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat.
Over 30 d ...
,
vomiting
Vomiting (also known as emesis, puking and throwing up) is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose.
Vomiting can be the result of ailments like food poisoning, gastroenteritis, pre ...
, and the
gastrointestinal tract
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the Digestion, digestive system that leads from the mouth to the anus. The tract is the largest of the body's systems, after the cardiovascula ...
– could counteract the undesirable increase in activation of this receptor mediated by SRIs, thereby potentially improving
tolerability
In pharmacology, tolerability refers to the degree to which overt adverse effects of a drug can be tolerated by a patient. Tolerability of a particular drug can be discussed in a general sense, or it can be a quantifiable measurement as part of a ...
.
An alternative term is serotonin partial agonist/reuptake inhibitor (SPARI), which can be applied only to vilazodone.
It is similar to the marketing strategy used for the drug
brexpiprazole
Brexpiprazole, sold under the brand name Rexulti among others, is an atypical antipsychotic medication used for the treatment of major depressive disorder, schizophrenia, and Agitation (dementia), agitation associated with dementia due to Alzhe ...
, labeling it as a "serotonin-dopamine activity modulator" or 'SDAM'.
See also
*
List of antidepressants
This is a complete list of clinically approved prescription antidepressants throughout the world, as well as clinically approved prescription drugs used to augment antidepressants or mood stabilizers, by pharmacological and/or structural classific ...
*
Serotonin antagonist and reuptake inhibitor
Serotonin antagonist and reuptake inhibitors (SARIs) are a class of drugs used mainly as antidepressants, but also as anxiolytics and hypnotics. They act by antagonizing serotonin receptors such as 5-HT2A and inhibiting the reuptake of seroto ...
(SARI)
*
Selective serotonin reuptake inhibitor
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.
SSRIs primarily work by blo ...
(SSRI)
*
Noradrenergic and specific serotonergic antidepressant
Noradrenergic and specific serotonergic antidepressants (NaSSAs) are a class of psychiatric drugs used primarily as antidepressants. They act by antagonizing the α2-adrenergic receptor and certain serotonin receptors such as 5-HT2A and 5-HT ...
(NaSSA)
*
Tricyclic antidepressant
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. They are named after their chemical structure, which contains ...