Pristiq (O-desmethylvenlafaxine) the major active metabolite of venlafaxine, is an antidepressant from the serotonin-norepinephrine reuptake inhibitor (SNRI class). Pristiq may be used to treat major depressive disorder and is being studied for use in the management of vasomotor symptoms in postmenopausal women. It is formulated as an extended release tablet. FDA approved in 2008.
Pristiq is a selective serotonin and norepinephrine reuptake inhibitor. It lacks significant activity on muscarinic-cholinergic, H1-histaminergic, or α1-adrenergic receptors in vitro. Pristiq does not appear to exert activity against calcium, chloride, potassium and sodium ion channels and also lacks monoamine oxidase (MAO) inhibitory activity. It was also shown to lack significant activity again the cardiac potassium channel, hERG, in vitro. Compared to other SNRIs, pristiq undergoes simple metabolism, has a low risk of drug-drug interactions and does not have to be extensively titrated to reach a therapeutic dose. Some of the limitations of pristiq include moderate efficacy in the treatment of major depressive disorder, similar safety and tolerability profile to other SNRIs and possible transient discontinuation symptoms upon cessation of therapy.
The safety and tolerability of pristiq is similar to other SNRIs. Common side effects upon initiation or dose increase include increased blood pressure and heart rate, agitation, tremor, sweating, nausea, headache, and sleep disturbances. May cause sexual dysfunction and weight loss in some patients. May cause increases in fasting serum total cholesterol, LDL cholesterol, and triglycerides. Withdrawal effects may occur and thus, the dose of pristiq should be titrated down prior to discontinuation.