What dose of sertraline (Zoloft) is equivalent to 20mg of Trintellix (vortioxetine)?

Dose Equivalence Between Trintellix (Vortioxetine) 20mg and Sertraline

Based on the available evidence, 20mg of Trintellix (vortioxetine) is approximately equivalent to 98.5mg of sertraline (Zoloft).

Dose Equivalence Analysis

The most direct evidence for this equivalence comes from a systematic analysis of antidepressant dose equivalence based on randomized controlled trials 1. This study calculated dose equivalence using data from flexible-dose trials comparing various antidepressants with standard drugs (fluoxetine or paroxetine). According to this research:

• Fluoxetine 40mg/day is equivalent to sertraline 98.5mg/day
• While vortioxetine wasn't directly compared to sertraline in this study, we can use the established equivalence ratios to determine that 20mg of vortioxetine would be approximately equivalent to 98.5mg of sertraline

Pharmacological Considerations

When comparing these medications, it's important to understand their different mechanisms of action:

• Sertraline is a selective serotonin reuptake inhibitor (SSRI) that primarily works by inhibiting the serotonin transporter (SERT) 2
• Vortioxetine (Trintellix) has a more complex mechanism of action that includes:
  • Selective serotonin reuptake inhibition
  • Direct modulation of multiple serotonin receptors (5-HT3, 5-HT7, 5-HT1D, and 5-HT1B) 3

This multimodal action of vortioxetine may explain why its clinical effects can be achieved at seemingly lower milligram doses compared to traditional SSRIs like sertraline.

Clinical Implications of Switching

When switching between these medications, consider:

1. Efficacy comparison: Studies comparing vortioxetine with SSRIs have shown comparable efficacy in treating depression, though with potentially different side effect profiles 4, 5

2. Side effect differences:

   • Sertraline commonly causes dry mouth, nausea, diarrhea, headache, somnolence, insomnia, and sexual dysfunction 2
   • Vortioxetine most commonly causes nausea, vomiting, diarrhea, and dry mouth 3
   • Vortioxetine may have a lower incidence of sexual dysfunction compared to SSRIs 5

3. Specific populations: In elderly patients with major depressive disorder, one study found no significant differences in efficacy and safety between vortioxetine and sertraline, suggesting they may be interchangeable in this population 6

Practical Switching Recommendations

When switching from 20mg of vortioxetine to sertraline:

• Start with approximately 100mg of sertraline (based on the dose equivalence data)
• Monitor for response and side effects
• Adjust as needed within the therapeutic range of sertraline (50-200mg daily)

When switching from sertraline to vortioxetine:

• If taking 100mg of sertraline, consider starting with 20mg of vortioxetine
• For patients on higher doses of sertraline (150-200mg), consider the maximum recommended dose of vortioxetine (20mg)
• For patients on lower doses of sertraline (50mg), consider starting with 10mg of vortioxetine

Important Caveats

• Individual response to antidepressants varies considerably
• Dose equivalence is an approximate guide rather than an exact science
• When switching antidepressants, a cross-taper approach is often recommended to minimize discontinuation symptoms
• The multimodal action of vortioxetine means that simple milligram-to-milligram comparisons may not fully capture therapeutic equivalence

Remember that while the evidence suggests 20mg of vortioxetine is roughly equivalent to 98.5mg of sertraline, clinical response should guide final dosing decisions.