How do I cross-taper a patient from Viibryd (vilazodone) to Trintellix (vortioxetine)?

Cross-Tapering from Viibryd (Vilazodone) to Trintellix (Vortioxetine)

Gradually taper vilazodone over 2-4 weeks while initiating vortioxetine during the final stages of the taper or after completion, starting vortioxetine at 10 mg daily and titrating to 20 mg as tolerated. 1

Rationale for Sequential Tapering

• Both vilazodone and vortioxetine are serotonergic antidepressants, and starting vortioxetine without properly tapering vilazodone could potentially increase the risk of serotonin syndrome. 1
• Vilazodone, as a selective serotonin reuptake inhibitor with 5-HT1A partial agonist activity, is associated with discontinuation syndrome when stopped abruptly, characterized by dizziness, fatigue, nausea, sensory disturbances, anxiety, and irritability. 1, 2
• Gradual tapering is prudent to avoid withdrawal symptoms and to prevent unexpected return of depressive symptoms weeks to months after the last dose. 1

Recommended Cross-Tapering Protocol

Vilazodone Taper Schedule

• Week 1-2: Reduce vilazodone dose by 25-50% of the original dose (e.g., from 40 mg to 20 mg daily). 1, 3
• Week 3-4: Further reduce to 10 mg daily or discontinue entirely depending on patient tolerance. 1
• The vilazodone taper should occur over a minimum of 2-4 weeks rather than stopping abruptly. 1

Vortioxetine Initiation Timing

• Begin vortioxetine after completing the vilazodone taper or during the final stages of tapering when on a very low dose of vilazodone (10 mg or less). 1
• Initial dose: Start vortioxetine at 10 mg once daily without regard to food. 4
• Titration: Increase to 20 mg daily after 1-2 weeks if the 10 mg dose is tolerated, as 20 mg/day is the effective dose demonstrated in US studies. 4
• For patients who do not tolerate 20 mg daily, 10 mg daily can be used, and a 5 mg daily dose can be considered. 4

Essential Monitoring During Transition

• Weekly assessments should include: mood symptoms, anxiety levels, suicidal ideation or behavior, sleep patterns, appetite and weight changes, and any discontinuation symptoms. 1
• Monitor specifically for vilazodone withdrawal symptoms including dizziness, nausea, sensory disturbances, anxiety, and irritability. 1, 2
• Monitor for serotonin syndrome symptoms such as confusion, agitation, muscle rigidity, and hyperthermia during the overlap period, though risk is relatively low with this specific combination. 1, 3
• Assess for vortioxetine-related adverse effects, particularly nausea (the most common side effect), which is dose-dependent. 4

Managing Withdrawal and Adverse Effects

• If moderate to severe withdrawal symptoms occur during vilazodone tapering, return to the previous dose and stabilize for 1-2 weeks, then resume tapering at a slower rate. 3, 5
• Do not misinterpret discontinuation symptoms as relapse—withdrawal symptoms typically emerge within days and are self-limiting, whereas true relapse develops more gradually over weeks. 1
• Vortioxetine-related nausea typically resolves within 4-5 days after starting the medication and is generally self-limited. 2
• If severe symptoms develop during tapering that pose safety concerns, extend each reduction phase by 1-2 weeks. 1

Critical Pitfalls to Avoid

• Do not start vortioxetine at full therapeutic dose (20 mg) while still on significant amounts of vilazodone, as this increases the risk of serotonergic adverse effects. 1, 3
• Avoid abrupt discontinuation of vilazodone, which can trigger severe withdrawal symptoms. 1, 3
• Do not rush the taper—some patients may require slower tapering if withdrawal symptoms emerge, potentially extending the timeline to 6-8 weeks. 1
• Educate patients about the importance of not missing doses of vortioxetine once established, as both medications can cause discontinuation syndromes. 1

Special Considerations

• Vortioxetine demonstrates improvement in depressive symptoms within 2 weeks, with full therapeutic effect observed at 4-6 weeks. 2
• Both vilazodone and vortioxetine have lower incidences of sexual side effects compared to traditional SSRIs, making this transition potentially advantageous for patients experiencing sexual dysfunction. 2, 6, 7
• No dose adjustment of vortioxetine is needed based on age, gender, or presence of renal or mild to moderate hepatic impairment. 4
• When eventually discontinuing vortioxetine in the future, doses of 15 mg/day or 20 mg/day should be reduced to 10 mg/day for 1 week prior to full discontinuation to avoid potential withdrawal symptoms. 4