What is the recommended dosing for Effexor XR (venlafaxine) for anxiety?

Effexor XR Dosing for Anxiety

For generalized anxiety disorder, start Effexor XR at 75 mg once daily, which can be increased to 150-225 mg/day based on response and tolerability, with dose increases of up to 75 mg at intervals of no less than 4 days. 1

Initial Dosing Strategy

• Begin with 75 mg once daily for patients with generalized anxiety disorder without major depression 2
• The extended-release formulation permits convenient once-daily dosing due to its sufficiently long elimination half-life 3
• Take with food to improve tolerability 1

Dose Titration

• Increase in increments of up to 75 mg at intervals of no less than 4 days if additional clinical effect is needed 1
• The therapeutic range for anxiety is typically 75-225 mg/day 4, 5, 2
• Response may be evident as early as week 1-2, with continued improvement through week 12 4, 5

Special Population Adjustments

Hepatic Impairment

• Reduce total daily dose by 50% in patients with mild to moderate hepatic impairment 1
• Individual variability is substantial; some patients with severe cirrhosis may require dose reductions exceeding 50% 1

Renal Impairment

• Reduce total daily dose by 25% for GFR 10-70 mL/min 1
• Reduce total daily dose by 50% for patients on hemodialysis 1

Elderly Patients

• No systematic dose adjustment required based solely on age 1
• Exercise caution when increasing doses in elderly patients 1

Monitoring Requirements

• Monitor height, weight, pulse, and blood pressure at baseline and during treatment 3
• SNRIs including venlafaxine have been associated with sustained hypertension, increased blood pressure, and increased pulse 3
• No specific laboratory tests are routinely recommended 3

Common Adverse Effects to Anticipate

• Nausea, dry mouth, abdominal discomfort, dizziness, headache, insomnia or somnolence, sweating, decreased appetite, and weight loss 3, 5
• Discontinuation due to adverse events occurs in approximately 11% of patients 5
• Nausea is typically the most common side effect 4

Critical Safety Considerations

• Monitor for suicidal thinking and behavior in patients through age 24 years 3
• Watch for behavioral activation, agitation, hypomania, or mania 3
• Venlafaxine may be associated with greater suicide risk than other SNRIs and has been associated with overdose fatalities 3
• Contraindicated with MAOIs due to serotonin syndrome risk 3

Discontinuation Protocol

• Taper gradually over 10-14 days to minimize withdrawal symptoms 6
• A discontinuation syndrome has been reported following missed doses or acute discontinuation 3
• The 37.5 mg/day dose is intended for gradual tapering when stopping treatment, not as an initial therapeutic dose 6

Efficacy Timeline

• Anxiolytic effects may begin as early as week 1 in patients with anxiety symptoms 5
• Significant improvement typically evident by weeks 4-6 4, 2
• Response rates at 12 weeks are approximately 44% (versus 30% with placebo) 4
• Remission rates at 12 weeks are approximately 20% (versus 7% with placebo) 4