Venlafaxine (Effexor) Dosage Recommendations
The recommended starting dose for venlafaxine is 75 mg/day, administered in two or three divided doses, taken with food, with potential increases to 150 mg/day and up to a maximum of 225 mg/day for outpatients or 375 mg/day for severely depressed inpatients. 1
Initial Dosing and Titration
- Starting dose is 75 mg/day, administered in two or three divided doses with food 1
- Dose increases should be made at intervals of no less than 4 days, in increments of up to 75 mg/day 1
- For moderately depressed outpatients, doses greater than 225 mg/day showed no additional benefit 1
- More severely depressed inpatients may respond better to higher doses, with a mean effective dose of 350 mg/day 1, 2
- The maximum recommended dose is 375 mg/day, generally administered in three divided doses 1
Dose-Response Relationship
- For most patients, 75 mg/day is sufficient for treatment 2
- Higher doses (150-225 mg/day) are associated with better response in severely ill patients 3, 2
- Venlafaxine's mechanism is dose-dependent: at lower doses it primarily affects serotonin reuptake, while at higher doses it also inhibits norepinephrine reuptake 2
- Early responses are typically seen at higher dosages 4
Special Populations
Hepatic Impairment
- For mild to moderate hepatic impairment, reduce total daily dose by 50% 1
- Further dose reduction may be necessary for patients with cirrhosis, with individualized dosing recommended 1
Renal Impairment
- For mild to moderate renal impairment (GFR 10-70 mL/min), reduce total daily dose by 25% 1
- For patients on hemodialysis, reduce total daily dose by 50% 1
- Individualized dosing may be necessary due to variability in clearance 1
Elderly Patients
- No specific dose adjustment is recommended based on age alone 1
- Exercise caution when increasing the dose in elderly patients 1
Safety Considerations
- Blood pressure monitoring is important, particularly at higher doses 3
- Dose-dependent blood pressure elevation occurs in approximately:
- 3-5% of patients receiving ≤200 mg/day
- 7% of patients receiving 201-300 mg/day
- 13% of patients receiving >300 mg/day 4
- Common adverse effects include nausea (most common but typically resolves within 1-3 weeks), dizziness, constipation, sweating, nervousness, and abnormal ejaculation 4
- Discontinuation rates due to adverse effects are similar to newer antidepressants 4
Maintenance Treatment
- For major depressive disorder, sustained pharmacological therapy beyond the acute response phase is generally recommended 1
- Maintenance treatment should continue at the same dose that was effective during acute treatment 1
Important Clinical Considerations
- A stepwise dosage regimen is recommended, with dose increases for non-responders before discontinuing treatment 2
- When discontinuing venlafaxine, taper the medication over 10-14 days to limit withdrawal symptoms 3
- Cardiac conduction abnormalities have been reported in a small number of patients, requiring caution in those with cardiac disease 3
- For neuropathic pain management, the efficacious dosage range is typically 150-225 mg/day 3