What is the equivalent dose of sertraline (Selective Serotonin Reuptake Inhibitor) for 20mg of Lexapro (escitalopram)?

Escitalopram 20mg to Sertraline Dose Equivalence

The approximate equivalent dose of sertraline for escitalopram 20mg is 100mg daily, though some patients may require 100-150mg to achieve comparable therapeutic effect. 1

Evidence-Based Dose Comparison

The most direct evidence comes from a head-to-head randomized controlled trial comparing escitalopram 10mg fixed-dose with sertraline flexibly dosed 50-200mg (mean final dose 144mg, median 150mg) in major depressive disorder. 1 This study demonstrated:

• No significant efficacy differences between escitalopram 10mg and sertraline at a mean dose of 144mg 1
• Both treatments achieved similar response rates (75% vs 70%) and mean MADRS score reductions (-19.1 vs -18.4) 1
• Both were well-tolerated with low discontinuation rates (2% vs 4%) 1

Practical Dosing Algorithm

For switching from escitalopram 20mg to sertraline:

1. Start sertraline at 100mg daily as the initial equivalent dose 1
2. Monitor response over 3-4 weeks at this dose 2, 3
3. If inadequate response after 3 weeks, consider titration to 150mg daily 2
4. Maximum dose is 200mg daily if needed, though most patients respond to 50-100mg 4, 3

Key Clinical Considerations

• Sertraline 50mg is the standard starting and often optimal therapeutic dose for most patients with depression 4, 3
• Evidence suggests limited dose-response relationship above 50mg for sertraline—continued treatment at 50mg yields comparable response to escalation to 150mg in many patients 2
• However, since escitalopram 20mg represents a higher-than-starting dose, beginning at 100mg sertraline is more appropriate than 50mg 1

Pharmacokinetic Differences to Consider

Therapeutic plasma concentration monitoring shows sertraline has a recommended range of 10-50 ng/mL, while escitalopram (measured as S-citalopram at 10mg dose) achieves 27-28 ng/mL. 5 These different ranges reflect distinct pharmacokinetic profiles and cannot be directly compared.

Important Switching Considerations

• Sertraline has a shorter half-life than escitalopram, requiring attention to discontinuation symptoms if cross-tapering 6
• Direct switch is generally safe as both are SSRIs with similar mechanisms 6
• Monitor for common side effects including nausea, dry mouth, drowsiness, and sexual dysfunction at the new dose 6
• Sertraline has favorable drug interaction profile due to less CYP450 inhibition compared to other SSRIs 6

Clinical Pitfalls to Avoid

• Do not assume linear dose equivalence—SSRI dose relationships are not proportional across medications 1
• Avoid starting too low (e.g., 50mg) when switching from escitalopram 20mg, as this may lead to inadequate response and unnecessary dose adjustments 1
• Do not automatically escalate beyond 100-150mg without adequate trial duration, as sertraline shows flat dose-response curve in many patients 2, 3
• Watch for discontinuation syndrome if abruptly stopping escitalopram rather than cross-tapering 6