Switching from Lexapro 15mg to Venlafaxine
When switching from escitalopram (Lexapro) 15mg to venlafaxine, use a conservative cross-taper approach: gradually taper escitalopram over 1-2 weeks while simultaneously starting venlafaxine at a low dose (37.5mg daily), then titrate venlafaxine upward as escitalopram is discontinued. 1, 2
Switching Strategy
Cross-Taper Approach (Recommended)
The most practical method for switching between these SSRIs/SNRIs involves overlapping the medications briefly:
- Week 1: Reduce escitalopram from 15mg to 10mg daily while starting venlafaxine 37.5mg once or twice daily 3, 2
- Week 2: Reduce escitalopram to 5mg daily while increasing venlafaxine to 75mg daily 3, 1
- Week 3: Discontinue escitalopram completely and increase venlafaxine to 150mg daily if tolerated 3, 1
- Week 4-6: Continue titrating venlafaxine by 75mg weekly as needed, up to a maximum of 225mg daily 3
This cross-taper minimizes both discontinuation symptoms from escitalopram and allows gradual introduction of venlafaxine to assess tolerability 2, 4.
Alternative Conservative Approach
If the patient has experienced significant side effects with medication changes previously, consider a more conservative taper-and-switch:
- Taper escitalopram by 5mg every 3-7 days until discontinued 3, 2
- Wait 1-2 days after complete discontinuation 2
- Start venlafaxine at 37.5mg daily, then increase by 75mg each week 3, 1
Critical Safety Considerations
Discontinuation Syndrome Risk
Both escitalopram and venlafaxine can cause withdrawal symptoms if stopped abruptly 3, 1. Escitalopram has a relatively lower risk compared to shorter-acting SSRIs like paroxetine, but gradual tapering remains essential 3. Venlafaxine specifically requires careful tapering as discontinuation syndrome is well-documented with this agent 3, 1.
Discontinuation symptoms to monitor include: dizziness, fatigue, headaches, nausea, sensory disturbances, anxiety, irritability, and flu-like symptoms 3, 1.
Serotonin Syndrome Precautions
While switching between an SSRI and SNRI carries lower risk than MAOI combinations, monitor for serotonin syndrome during the overlap period 3, 1. Warning signs include: mental status changes (confusion, agitation), neuromuscular hyperactivity (tremors, hyperreflexia), and autonomic instability (hypertension, tachycardia, diaphoresis) 3.
The cross-taper approach described above is generally safe as both medications work through serotonergic mechanisms, but avoid combining with other serotonergic agents during the switch 3, 1.
Venlafaxine-Specific Monitoring
Baseline and Ongoing Assessments
Before and during venlafaxine treatment, monitor 3:
- Blood pressure and pulse: Venlafaxine can cause sustained hypertension and increased heart rate, particularly at higher doses 3
- Weight: Monitor for appetite changes and weight loss 3
- Cardiac history: Use caution in patients with cardiac disease due to potential conduction abnormalities 3
Dosing Considerations
Standard titration schedule 3, 1:
- Starting dose: 37.5mg once or twice daily
- Increase by 75mg weekly as tolerated
- Therapeutic range: 150-225mg daily
- Maximum dose: 225mg daily (375mg in some treatment-resistant cases)
- Duration for adequate trial: 4-6 weeks at therapeutic dose 3
Take venlafaxine with food to minimize gastrointestinal side effects 1.
Expected Efficacy
Switching from an SSRI to venlafaxine shows variable response rates depending on depression severity 5, 6:
- In patients with moderate depression (HAM-D ≤31), switching to venlafaxine shows similar efficacy to switching to another SSRI like citalopram 5
- In more severely depressed patients (HAM-D >31), venlafaxine demonstrates superior efficacy compared to switching to another SSRI 5
- Overall response rates after switching range from 48-59%, with remission rates of 37-41% 5, 7
Evidence does not strongly support that dual-action antidepressants like venlafaxine are universally superior to SSRIs, though they may offer advantages in specific populations 6, 7.
Common Pitfalls to Avoid
Do not abruptly discontinue escitalopram without tapering, as this increases risk of discontinuation syndrome even though escitalopram has a relatively favorable profile 3, 2.
Do not rapidly titrate venlafaxine to high doses—this increases adverse effects including nausea, hypertension, and discontinuation rates 3.
Do not combine with MAOIs—allow at least 7 days after stopping venlafaxine before starting an MAOI, and 14 days after stopping an MAOI before starting venlafaxine 1.
Monitor for treatment-emergent suicidal ideation, particularly in patients under age 25 3, 1.