Serotonin and norepinephrine reuptake inhibitors


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Serotonin and norepinephrine reuptake inhibitors

Behavioral sciences


Selective serotonin reuptake inhibitors

Serotonin and norepinephrine reuptake inhibitors

Tricyclic antidepressants

Monoamine oxidase inhibitors

Atypical antidepressants


Typical antipsychotics

Atypical antipsychotics

Mood stabilizers


Nonbenzodiazepine anticonvulsants

Atypical antipsychotics

Anxiolytics and hypnotics

Anticonvulsants and anxiolytics: Barbiturates

Anticonvulsants and anxiolytics: Benzodiazepines

Psychomotor stimulants

Psychomotor stimulants


Serotonin and norepinephrine reuptake inhibitors


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Serotonin and norepinephrine reuptake inhibitors

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External References

First Aid









serotonin-norepinephrine reuptake inhibitors (SNRIs) for p. 599

Generalized anxiety disorder (GAD) p. 585, 586

serotonin-norepinephrine reuptake inhibitors (SNRIs) for p. 599

Serotonin-norepinephrine reuptake inhibitors (SNRIs)

SNRIs (serotonin-norepinephrine reuptake inhibitors ) p. 599


Content Reviewers

Yifan Xiao, MD


Filip Vasiljević, MD

Elizabeth Nixon-Shapiro, MSMI, CMI

Evan Debevec-McKenney

Serotonin norepinephrine reuptake inhibitors, or SNRIs, are mainly used to treat major depressive disorder.

This disorder causes a persistent feeling of sadness and loss of interest in everyday activities.

Even though the exact cause of depression is still unknown, there's some evidence that suggests it’s related to low levels of neurotransmitters like serotonin, norepinephrine, and dopamine.

Serotonin norepinephrine reuptake inhibitors work by increasing the levels of serotonin and norepinephrine to alleviate the symptoms of depression.

Alright, now within the brain, there are many different types of neurons, but we’re going to focus only on two: serotonergic neurons which produce serotonin, and noradrenergic neurons which produces norepinephrine.

Each of these neurons synthesizes and stores their neurotransmitters in small vesicles.

So, when an action potential reaches the presynaptic membrane, these vesicles fuse with the membrane, releasing neurotransmitters in the synaptic cleft.

Once released, serotonin or 5-HT binds to 5-HT2 receptors on the postsynaptic membrane, thereby increasing neural stimulation and regulating mood, feeding, and reproductive behavior.

On the other hand, norepinephrine binds to norepinephrine receptors on the postsynaptic membrane, boosting alertness.

As long as there’s a high enough concentration of neurotransmitters in the synaptic cleft, the postsynaptic neurons will continue to fire.

Now, serotonergic neurons on their presynaptic membrane have serotonin transporters or SERT, while noradrenergic neurons have norepinephrine transporters or NET.


Serotonin and norepinephrine reuptake inhibitors (SNRIs) are a class of antidepressant medications used to treat major depressive disorder and other mental health conditions such as anxiety disorders, obsessive-compulsive disorder, and attention deficit hyperactivity disorder. SNRIs work by preventing serotonin and norepinephrine reuptake from the synaptic cleft, thus enhancing the effect of both neurotransmitters on the postsynaptic neuron. SNRIs can cause a few dangerous side effects like increased risk of suicide and life-threatening serotonin syndrome.


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