How should I switch a patient with major depressive disorder from Trintellix (vortioxetine) to Auvelity (dextromethorphan/bupropion)?

Switching from Trintellix to Auvelity in Major Depressive Disorder

When switching a patient with MDD from Trintellix (vortioxetine) to Auvelity (dextromethorphan/bupropion), perform a direct cross-taper without a washout period, as neither medication requires the 14-day MAOI washout that Auvelity mandates. 1

Switching Strategy

Step 1: Assess Patient Suitability for Auvelity

Before initiating the switch, screen for absolute contraindications 1:

• Seizure history or disorder (contraindicated)
• Current or prior bulimia/anorexia nervosa (contraindicated due to increased seizure risk)
• Recent abrupt discontinuation of alcohol, benzodiazepines, barbiturates, or antiepileptic drugs (contraindicated)
• MAOI use within 14 days (contraindicated)
• Uncontrolled hypertension (measure baseline blood pressure)
• Bipolar disorder history (screen for personal/family history of mania/hypomania)
• Renal impairment (if moderate [eGFR 30-59], dose adjustment required)
• CYP2D6 poor metabolizer status (dose adjustment required)

Step 2: Execute the Cross-Taper

Direct cross-taper approach (supported by evidence showing switching between second-generation antidepressants is generally well-tolerated) 2:

Days 1-3:

• Continue Trintellix at current dose
• Start Auvelity 1 tablet (45mg/105mg) once daily in the morning
• Monitor for adverse effects, particularly nausea, dizziness, and activation symptoms

Day 4 onward:

• Discontinue Trintellix completely
• Increase Auvelity to 1 tablet twice daily (at least 8 hours apart)
• This is the target maintenance dose

Step 3: Critical Monitoring Points

Week 1-2 monitoring 3, 1:

• Suicidal ideation (FDA black box warning requires close monitoring, especially in patients <24 years)
• Blood pressure (check at baseline and periodically; Auvelity can increase BP)
• Seizure precautions (educate patient on risk factors)
• Activation symptoms (agitation, irritability, insomnia, restlessness suggesting emerging mania)
• Nausea/GI symptoms (most common reason for discontinuation in antidepressant trials) 3, 4

Weeks 2-6:

• Assess therapeutic response using standardized scales (MADRS or PHQ-9)
• Auvelity demonstrates efficacy as early as week 1, with significant improvement by week 6 5, 6
• If inadequate response by 6-8 weeks, consider alternative strategies 3

Key Advantages of This Switch

The evidence supports this direct approach because:

• No washout required: Trintellix is not an MAOI, so the 14-day washout mandated for MAOIs does not apply 1
• Different mechanisms: Vortioxetine (multimodal serotonergic) versus Auvelity (NMDA antagonist/sigma-1 agonist plus NDRI) minimizes overlapping pharmacology 5, 7
• Rapid onset: Auvelity shows improvement within 1 week, potentially minimizing the symptomatic gap during transition 6
• Low discontinuation syndrome risk: Moderate-quality evidence shows switching between second-generation antidepressants has similar discontinuation rates and tolerability 2

Common Pitfalls to Avoid

1. Do not use a washout period unless the patient is on an MAOI (which Trintellix is not). Unnecessary washouts increase risk of depressive relapse 8

2. Do not exceed 2 tablets of Auvelity per day or take doses <8 hours apart (seizure risk increases with higher doses) 1

3. Do not combine with other bupropion-containing products (check for Wellbutrin, Zyban, Contrave) as this increases seizure risk 1

4. Do not ignore alcohol use patterns: If patient drinks heavily, sudden alcohol cessation during the switch increases seizure risk; address this proactively 1

5. Adjust dosing for special populations: Patients with moderate renal impairment, CYP2D6 poor metabolizers, or those on strong CYP2D6 inhibitors require reduced dosing (1 tablet once daily) 1

Clinical Context

Real-world data shows that 71.2% of patients initiate Auvelity as add-on therapy rather than monotherapy, with 28.8% using it as monotherapy 9. However, for a direct switch scenario, the cross-taper monotherapy approach is appropriate. The evidence base shows no significant differences in efficacy when switching between second-generation antidepressants 2, making this a reasonable strategy when Trintellix has failed or is poorly tolerated.

The 2023 ACP guidelines confirm that switching strategies between antidepressants show similar benefits, with treatment selection based primarily on adverse effect profiles and patient preferences 10. Auvelity's unique rapid onset (1 week vs. 4-6 weeks for traditional antidepressants) and novel mechanism make it a compelling option for patients who have not responded to serotonergic agents like Trintellix 5, 6.