Qualitative Review of SNRIs in Anxiety

Anxiety disorders pose a problem for a significant number of individuals, with a 1-year prevalencerate estimated at 13.1% to 17.1%. Many pharmacologic agents have been used to treat anxiety disorders,and among those in current use are newer benzodiazepines (alprazolam), azapirones (buspirone),selective serotonin reuptake inhibitors (paroxetine and sertraline), and venlafaxine, a serotonin-norepinephrinereuptake inhibitor (SNRI). The likely role of abnormal serotonergic neurotransmissionin anxiety is widely supported, while the role of norepinephrine is less clear. Still, many lines ofevidence support the hypothesis that a perturbation in norepinephrine neurotransmission contributesto the symptoms of anxiety. Therefore, it is conceivable that modulation of both serotonin and norepinephrinesystems by dual-reuptake inhibitors may be an advantage in the treatment of anxiety disorders.Given this, the current review examines evidence on the possible role of venlafaxine in the treatmentof anxiety disorders. From this review it is clear that venlafaxine is as efficacious as selectiveserotonin reuptake inhibitors in treating anxiety, with comparable tolerability. Future research will bevaluable in determining if antidepressants that combine pharmacologic actions on serotonergic andnoradrenergic systems have advantages over more selective agents in treating anxiety disorders.