Venlafaxine Drug Classification
Venlafaxine is a serotonin-norepinephrine reuptake inhibitor (SNRI), a class of medications that inhibit the presynaptic reuptake of both serotonin and norepinephrine in the brain. 1, 2
Mechanism of Action
The SNRI medication class consists of chemically and pharmacologically different compounds that inhibit the presynaptic reuptake of both norepinephrine and serotonin in the brain. 1
The FDA label confirms that venlafaxine's antidepressant action is believed to be associated with its potentiation of neurotransmitter activity in the CNS through potent inhibition of neuronal serotonin and norepinephrine reuptake, with weak dopamine reuptake inhibition. 2
Venlafaxine demonstrates approximately 30-fold selectivity for serotonin over norepinephrine reuptake inhibition, meaning it blocks serotonin reuptake more potently than norepinephrine at lower doses. 3
In vivo studies indicate that venlafaxine selectively inhibits serotonin uptake at low therapeutic doses and inhibits both serotonin and norepinephrine uptake at higher therapeutic doses. 4
Other SNRIs in the Class
Medications from the SNRI class currently marketed in the United States include venlafaxine, desvenlafaxine, duloxetine, and levomilnacipran. 1
- Although mechanisms of action vary somewhat across SNRIs (effects on other neurotransmitter receptors affecting degree of serotonin and norepinephrine selectivity), the primary mechanism is sufficiently similar across individual medications to warrant extension of findings to the medication class. 1
Important Distinguishing Features
Venlafaxine and its active metabolite O-desmethylvenlafaxine (ODV) have no significant affinity for muscarinic, histaminergic, or α-1 adrenergic receptors, and do not possess monoamine oxidase (MAO) inhibitory activity. 2