Wyeth; patent expires 2008. IR version available as generic.
Generalized Anxiety Disorder
Social Anxiety Disorder
Serotonin and Norepinephrine Reuptake Inhibitor
XR formulation supplied in 37.5 mg, 75 mg, and 150 mg capsules; IR (immediate release) formulation supplied in 25 mg, 37.5 mg, 50 mg, 75 mg, and 100 mg tablets.
"Magic dose" to aim for: 150 mg, which is the dose at which norepinephrine reuptake inhibition kicks in.
Give patient two things: 1) "starter pack" (one week each of 37.5 mg and 75 mg) and 2) a prescription for 150 mg Q PM.
Evening dosing works well for most patients, taking advantage of initial sedative effects.
Geriatric patients tend to tolerate same dosing schedule as younger patients.
Most common are nausea, dizziness, fatigue, sexual dysfunction.
Treatment-emergent BP elevation is possible at higher doses, uncommon with doses below 300 mg.
Black Box Warning: In clinical trials, SSRIs and SNRIs increased the risk of suicidality in children (from 2% to 4%). No actual suicides occurred in these trials.
Pregnancy Risk Category C
Only significant interactions are that Wellbutrin and Benadryl can increase Effexor serum levels.
Effexor may be more effective than SSRIs in bringing about complete remission of depressive symptoms, though more recent studies are calling this into question.