Starting Dose of Effexor (Venlafaxine) for Adults
The recommended starting dose of venlafaxine (Effexor) for adults is 75 mg/day, administered in two or three divided doses, taken with food. 1
Dosing Guidelines
Initial Dosing
- Starting dose: 75 mg/day divided into 2-3 doses with food 1
- For extended-release (XR) formulation: 75 mg once daily 2
Dose Titration
- Dose may be increased to 150 mg/day based on clinical response and tolerability
- Further increases up to 225 mg/day may be made if needed
- When increasing the dose, increments of up to 75 mg/day should be made at intervals of no less than 4 days 1
- Maximum recommended dose: 375 mg/day (generally in three divided doses) 1
Special Populations
Hepatic Impairment
- For mild to moderate hepatic impairment: Reduce total daily dose by 50%
- Individual dose adjustments may be necessary due to variability in clearance among patients with cirrhosis 1
Renal Impairment
- Mild to moderate renal impairment (GFR 10-70 mL/min): Reduce total daily dose by 25%
- Patients undergoing hemodialysis: Reduce total daily dose by 50%
- Individual dose adjustments may be necessary due to variability in clearance 1
Elderly Patients
- No specific dose adjustment is recommended based on age alone
- However, extra caution should be exercised when increasing the dose in elderly patients 1
Clinical Considerations
Efficacy
- A minimum effective dose of 75 mg/day has been established 3
- A positive dose-response relationship has been demonstrated with doses up to 375 mg/day 3
- For more severely depressed patients, higher doses (mean 350 mg/day) may be more effective 1
Formulation Differences
- Immediate-release (IR): Usually administered in 2-3 divided doses
- Extended-release (XR): Can be administered once daily with similar efficacy and potentially better tolerability 2
Common Side Effects
- Nausea (especially during the first 2 weeks of treatment)
- Dizziness
- Somnolence
- Dry mouth
- Sweating 4
Important Monitoring Considerations
- Blood pressure should be monitored, as venlafaxine has been associated with modest increases in blood pressure, particularly at higher doses 5
- Assess for signs of serotonin syndrome when combining with other serotonergic medications
- Monitor for withdrawal symptoms if discontinuing; gradual tapering is recommended
Remember that while the starting dose is standardized at 75 mg/day, the therapeutic response and side effect profile will determine the optimal maintenance dose for each patient.