Serotonin Norepinephrine Reuptake Inhibitors

Serotonin norepinephrine reuptake inhibitors (SNRIs) are related to tricyclic antidepressants. SNRIs inhibit reuptake of both serotonin and norepinephrine; however, SNRIs have less alpha blockade, anticholinergic, and antihistamine effects. SNRIs are second line treatments for depression and are also used in the treatment of chronic pain syndromes.  SNRIs have similar rebound discontinuation effects.

Class Drugs

• Venlafaxine

• Desvenlafaxine

• Duloxetine

Class Mechanism of Action

• Blocks reuptake of serotonin and norepinephrine in central nervous system.

Class Application

Depression

• Increases serotonin/norepinephrine levels in the synaptic cleft.

• May have some effect in decreasing pain related to depression.

Pain syndromes

• Diabetic peripheral neuropathy

• Post-herpetic neuralgia

• Fibromyalgia

Class Adverse Effects

• Insomnia

• Sexual dysfunction

• Sedation

• Dizziness

• Increased heart rate

• Increased blood pressure

• Discontinuation syndrome

Occurs when SNRI is stopped suddenly.

Drug Table

Drug Name	Application	Comments	Image
Venlafaxine			"Van" and "Fax Machine"
Desvenlafaxine			"Desk" and "Van" and "Fax Machine"
Duloxetine		Rare Hepatotoxicity	"Two Oxen" "Eating"