Effexor Starting Dose
For adults, start Effexor (venlafaxine) at 37.5 mg per day, with the standard therapeutic dose being 75 mg per day; for patients over 65, start at approximately half the adult dose (around 37.5 mg per day or lower). 1
Adult Dosing
The FDA-approved dosing range for venlafaxine is 37.5 to 225 mg/day 2. Based on guideline recommendations and clinical trial data:
- Initial dose: 37.5-75 mg/day 1
- Standard therapeutic dose: 75 mg/day is the most consistently effective starting point 2
- The dose can be titrated upward if response is inadequate after 2 weeks, with increases to 150 mg/day or higher as needed 3
For the extended-release formulation (Effexor XR), clinical trials demonstrated that 75 mg once daily was effective and well-tolerated, with the option to increase to 150 mg daily if needed after 2 weeks 3. The immediate-release formulation is typically dosed as 37.5 mg twice daily initially 3.
Geriatric Dosing (Age 65+)
Older adults require approximately 50% of the standard adult starting dose due to significantly greater risk of adverse drug reactions 1. This translates to:
- Starting dose: 18.75-37.5 mg/day (approximately half the adult dose)
- Titrate more slowly and cautiously than in younger adults
- Monitor closely for hyponatremia, which occurs more frequently in elderly patients 2
The guideline explicitly states that "lower starting doses are often recommended (i.e., approximately 50% of the adult starting dose)" for older adults 1.
Important Dosing Considerations
Dose adjustments are required for renal or hepatic impairment 1. Venlafaxine requires dose reduction in both conditions, unlike some other antidepressants.
Common Pitfalls to Avoid:
- Don't start too high: While 75 mg/day is therapeutic, starting at 37.5 mg/day improves tolerability, particularly for nausea, which is most common in the first 2 weeks 3
- Don't underdose elderly patients long-term: While starting lower, many older adults will ultimately require standard therapeutic doses for efficacy 4
- Don't forget to monitor blood pressure: Venlafaxine can cause dose-dependent hypertension, particularly at doses above 150 mg/day 1
Formulation Differences:
The extended-release formulation (Effexor XR) allows once-daily dosing and has lower peak-to-trough fluctuations, which may improve tolerability compared to immediate-release formulations that require twice-daily dosing 3.