THERAPEUTICS

Brands

• Effexor, Effexor XR, Effexor XL, Efectin, Efexor, Trevilor, Venla

Generic?

• Yes

Class

• Serotonin and norepinephrine reuptake inhibitor (SNRI)

Commonly Prescribed for

(FDA approved in bold)

• Major depressive disorder

• Generalized anxiety disorder (Effexor XR only)

• Panic disorder (Effexor XR only)

• Social phobia (Effexor XR only)

• Migraine or tension-type headache prophylaxis

• Diabetic neuropathy

• Other painful peripheral neuropathies

• Cancer pain (neuropathic)

• Depression secondary to stroke

• Stress urinary incontinence

• Fibromyalgia

• Binge-eating disorder

• Post-traumatic stress disorder (PTSD)

• Attention deficit hyperactivity disorder

• Perimenopausal/menopausal hot flushes

• Cataplexy

How the Drug Works

• Both venlafaxine and its active metabolite (desvenlafaxine) are potent inhibitors of serotonin and norepinephrine reuptake transporters (SERT, NET), increasing serotonin and norepinephrine levels within hours, but antidepressant effects take weeks. Effect is more likely related to adaptive changes in serotonin and norepinephrine receptor systems over time

• Weakly blocks dopamine reuptake pump (dopamine transporter)

• Interacts with μ-opioid receptors and α2-adrenergic receptor

How Long Until It Works

• Migraines: effective in as little as 2 weeks, but can take up to 10 weeks on a stable dose to see full effect

• Tension-type headache prophylaxis: effective in 4–8 weeks

• Neuropathic pain: usually some effect within 4 weeks

• Diabetic neuropathy: may have significant improvement with high doses within 6 weeks

• Depression: 2 weeks but up to 2 months for full effect

If It Works

• Migraine/tension-type headache: goal is a 50% or greater reduction in headache frequency or severity. Consider tapering or stopping if headaches remit for more than 6 months or if considering pregnancy

• Neuropathic pain: the goal is to reduce pain intensity and symptoms, but usually does not produce remission. Continue to use and monitor for AEs

• Diabetic neuropathy: the goal is to reduce pain intensity and reduce use of analgesics, but usually does not produce remission. Continue to use and maintain strict glycemic control and diabetic management