Pristiq Drug Classification
Pristiq (desvenlafaxine) is a serotonin-norepinephrine reuptake inhibitor (SNRI).
Mechanism of Action
Desvenlafaxine works by inhibiting the presynaptic reuptake of both serotonin and norepinephrine in the central nervous system 1. The exact mechanism of its antidepressant action is thought to be related to the potentiation of these neurotransmitters in the CNS through inhibition of their reuptake 1. Non-clinical studies have demonstrated that desvenlafaxine is a potent and selective SNRI 1.
SNRI Class Characteristics
The SNRI medication class consists of chemically and pharmacologically different compounds that share the common mechanism of inhibiting presynaptic reuptake of both norepinephrine and serotonin 2. Medications currently marketed in the United States within the SNRI class include venlafaxine, desvenlafaxine, duloxetine, and levomilnacipran 2.
Key Distinguishing Features
- Desvenlafaxine is the major active metabolite of venlafaxine 1, 3
- Unlike venlafaxine, desvenlafaxine is not metabolized by CYP2D6 enzyme pathways and has minimal inhibition of CYP enzymes 4
- This results in a lower risk of drug-drug interactions compared to its parent compound 3, 4
- Desvenlafaxine has a sufficiently long elimination half-life to permit once-daily dosing 2
Clinical Context
The SNRI class is recommended as first-line treatment for moderate to severe major depressive disorder 5. Within this class, desvenlafaxine is approved by the FDA for treatment of MDD in adults at a recommended dose of 50 mg/day 1, 6. The drug lacks significant affinity for muscarinic-cholinergic, H1-histaminergic, or α1-adrenergic receptors, and does not have monoamine oxidase (MAO) inhibitory activity 1.
Important caveat: While some sources use the terminology "selective serotonin-norepinephrine reuptake inhibitor" (SSNRI) 7, the more commonly accepted and FDA-recognized classification is SNRI 1.