What is the use of venlafaxine (Effexor), a selective serotonin and norepinephrine reuptake inhibitor (SSNRI)?

From the Guidelines

Venlafaxine is primarily used to treat major depressive disorder, generalized anxiety disorder, social anxiety disorder, and panic disorder, as well as neuropathic pain, with a typical starting dose of 37.5 mg or 75 mg once daily, which can be gradually increased to a maximum of 225 mg daily for depression or 225-375 mg daily for anxiety disorders, depending on response and tolerability 1.

Key Points

• Venlafaxine belongs to the serotonin-norepinephrine reuptake inhibitor (SNRI) class, which works by increasing the levels of serotonin and norepinephrine in the brain to regulate mood and reduce anxiety 1.
• The medication is available in immediate-release tablets (taken 2-3 times daily) or extended-release capsules (taken once daily) 1.
• Common side effects include nausea, headache, dizziness, dry mouth, sweating, and sleep disturbances, and blood pressure should be monitored as venlafaxine can cause hypertension, particularly at higher doses 1.
• Venlafaxine should not be stopped abruptly as this can lead to discontinuation symptoms like dizziness, irritability, headaches, and flu-like symptoms 1.
• The medication typically takes 2-4 weeks to notice improvement in symptoms, though full benefits may take 6-8 weeks to develop 1.

Use in Neuropathic Pain

• Venlafaxine has shown efficacy in the treatment of neuropathic pain, particularly in painful diabetic neuropathy and painful polyneuropathies of different origins 1.
• The medication is typically titrated to an efficacious dosage of 150-225 mg/d, with cardiac conduction abnormalities and blood pressure increases being potential concerns 1.

Important Considerations

• Venlafaxine may be associated with greater suicide risk than other SNRIs, and both venlafaxine and desvenlafaxine have been associated with overdose fatalities 1.
• The medication should be prescribed with caution in patients with cardiac disease, and dosage adjustments may be necessary in patients with renal insufficiency 1.

From the FDA Drug Label

INDICATIONS AND USAGE Venlafaxine tablets, USP are indicated for the treatment of major depressive disorder The use of venlafaxine (Effexor), a selective serotonin and norepinephrine reuptake inhibitor (SSNRI), is for the treatment of major depressive disorder.

• The treatment is indicated for patients with a prominent and relatively persistent depressed or dysphoric mood that interferes with daily functioning.
• Key symptoms of major depressive disorder include:
  • Change in appetite
  • Change in sleep
  • Psychomotor agitation or retardation
  • Loss of interest in usual activities or decrease in sexual drive
  • Increased fatigue
  • Feelings of guilt or worthlessness
  • Slowed thinking or impaired concentration
  • A suicide attempt or suicidal ideation 2

From the Research

Use of Venlafaxine

• Venlafaxine, a selective serotonin and norepinephrine reuptake inhibitor (SSNRI), is used in the treatment of major depression and major depression associated with anxiety 3.
• The drug has a clear dose progression, with low doses predominantly binding to the 5-HT transporter and more binding of the NE transporter as the dose ascends 4.
• Venlafaxine is approved for major depressive disorder (MDD) as well as generalized anxiety disorder, social anxiety disorder, and panic disorder 4.

Dosage and Efficacy

• The efficacy of venlafaxine is dose-dependent, with higher doses producing greater improvements in depressive symptoms 3, 5.
• A study found that venlafaxine at a dosage of 75 mg/day is sufficient for the majority of cases, but higher dosages may be associated with additional benefits in extremely ill patients 5.
• A systematic review and dose-response meta-analysis found that the optimal dose of venlafaxine is around 75-150 mg, with higher doses showing a more modest increase in efficacy 6.

Tolerability and Safety

• Venlafaxine is generally well tolerated, with common adverse events including nausea, dizziness, somnolence, insomnia, dry mouth, and asthenia 3, 4.
• The drug may cause dose-dependent blood pressure elevation, but this is infrequently observed at doses below 225 mg per day 4.
• A study found that venlafaxine extended release is an efficient and safe therapeutic option for patients with major depressive disorder, with the additional effect of reducing associated painful physical symptoms 7.