Treatment of anxiety disorders with venlafaxine XR

When venlafaxine was introduced in 1994, it was the first of the newer generation antidepressants to be classified as a serotonin norepinephrine reuptake inhibitor (SNRI). An extended release (XR) formulation of venlafaxine, introduced in 1997, subsequently received regulatory approval for treatment of three anxiety disorders: generalized anxiety disorder, social anxiety disorder and panic disorder. Although less extensively studied, venlafaxine XR also appears to have efficacy for two other anxiety disorders, post-traumatic stress disorder and obsessive-compulsive disorder. In contrast to the treatment of depression, for which meta-analyses suggest an efficacy advantage relative to selective serotonin reuptake inhibitors (SSRIs), evidence of differential efficacy has not yet been established for any of the anxiety disorders. The overall tolerability profile of venlafaxine XR is generally comparable to that of the SSRIs, although there is greater incidence of noradrenergically mediated side effects (i.e., dry mouth and constipation), as well as a dose-dependent risk of treatment-emergent high blood pressure. Concerns about safety in overdose have also recently emerged. Despite these caveats, venlafaxine XR is an effective and generally well-tolerated option for treatment of anxiety disorders.