Amitriptyline and Etrasimod: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Amitriptyline
Etrasimod
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
You've been prescribed amitriptyline (Elavil) and etrasimod (Velsipity). Both of these can affect your heart's rhythm. Amitriptyline can stretch out part of your heartbeat (called the QT interval), and etrasimod can briefly slow your heart rate and its electrical signals, especially in the first days you start it. Together, there's a theoretical chance of an irregular heartbeat.
Please don't stop either medicine on your own. This is something your care team can plan for. Let your doctor and pharmacist know you take both, and tell them right away if you feel dizzy, faint, or notice a racing or fluttering heartbeat.
Effect: Additive cardiac risk. Amitriptyline prolongs the QT interval; etrasimod causes a transient reduction in heart rate and AV conduction delays on initiation. Combined, this raises theoretical risk of QT prolongation and torsades de pointes.
- Mechanism: Additive bradycardia plus additive QT prolongation (PD interaction, not metabolic). Neither is a prodrug affecting this.
- Onset: Unspecified; bradycardic effect notably at etrasimod initiation.
- Evidence: Theoretical.
- Management: Cardiology consultation before initiating etrasimod with a QT-prolonging agent. Consider baseline/periodic ECG, electrolyte correction (K+, Mg2+), and heart rate monitoring at initiation.
What happens
Increased risk of transient reduction in heart rate, AV conduction, QT interval prolongation and an increased risk of torsade de pointes
Interaction Deep Dive
Using etrasimod together with medications that prolong the QT interval may raise the likelihood of QT prolongation and torsades de pointes. When etrasimod therapy is started, patients may experience a temporary reduction in heart rate along with delays in AV conduction. Consult a cardiologist prior to beginning etrasimod in combination with other agents that prolong the QT interval1.
Why it happens (mechanism)
Additive heart rate reduction; additive QT interval prolongation
How to manage this interaction
The good news is that your care team can manage this by planning ahead and watching you closely.
- Keep taking both exactly as prescribed unless your doctor tells you otherwise.
- Because etrasimod can briefly slow the heart when you start it, your team may involve a cardiologist and check an ECG and your heart rate, especially at initiation.
- Your doses may need to be adjusted and individualized by your care team.
- Tell your pharmacist or doctor right away if you feel faint, dizzy, or notice a pounding or irregular heartbeat.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Amitriptyline and Etrasimod together?
Both drugs can affect heart rhythm, so this combination should be reviewed with a cardiologist before starting etrasimod, with heart monitoring at initiation. Keep taking both as prescribed and report any dizziness, fainting, or irregular heartbeat right away. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Amitriptyline and Etrasimod interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Amitriptyline and Etrasimod interaction managed?
The good news is that your care team can manage this by planning ahead and watching you closely. Keep taking both exactly as prescribed unless your doctor tells you otherwise. Because etrasimod can briefly slow the heart when you start it, your team may involve a cardiologist and check an ECG and your heart rate, especially at initiation. Your doses may need to be adjusted and individualized by yo… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Amitriptyline or Etrasimod need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (1)
- Product Information: VELSIPITY(TM) oral tablets, etrasimod oral tablets. Pfizer Labs (per FDA), New York, NY, 2023. DailyMed
Keep reading about Amitriptyline
Keep reading about Etrasimod
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