Amitriptyline and Amoxapine: 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
Amoxapine
No brand names on record
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.
Amitriptyline and amoxapine are both antidepressants, and they can each have a small effect on your heart's rhythm. That effect is measured as something called the QT interval. When you take both together, those effects can add up, which may slightly raise the chance of an irregular heartbeat.
The good news is that this concern is theoretical, meaning it is based on how these drugs work rather than a lot of real-world reports. Doctors don't usually prescribe these two together. If you are on both, please talk with your pharmacist or doctor. Your care team can keep an eye on this and manage it safely.
Effect: Additive QT-interval prolongation with concurrent amitriptyline and amoxapine, increasing risk of serious cardiovascular events (including torsades de pointes).
- Mechanism: Pharmacodynamic additivity; both TCAs/TCA-related agents can delay cardiac repolarization. No prodrug relationship applies.
- Direction: Additive PD effect, not a PK-driven exposure change.
- Onset: Unspecified.
- Evidence: Theoretical; concurrent use is uncommon.
- Management: Avoid combination where possible. If co-prescribed, obtain baseline/follow-up ECG, correct electrolytes (K+, Mg2+), review other QT-prolonging agents, and monitor for arrhythmia symptoms.
What happens
An increased risk of QT interval prolongation
Interaction Deep Dive
It is not standard clinical practice to combine amitriptyline with amoxapine. Nevertheless, should these two agents be administered together, caution is warranted because of the possibility of additive QT interval effects and a heightened risk of serious cardiovascular events1.
Why it happens (mechanism)
Additive effects on the QT interval
How to manage this interaction
These two antidepressants are rarely used together, but if your care team has prescribed both, this is manageable.
- Keep taking both exactly as prescribed unless your doctor tells you otherwise.
- Your team may monitor you more closely, which can include checking your heart rhythm (ECG) and blood electrolytes like potassium and magnesium.
- Doses may need to be adjusted and individualized by your care team.
- Tell your prescriber about any other medicines you take, since some also affect heart rhythm.
Call your doctor right away if you feel fainting, dizziness, a racing or pounding heartbeat, or palpitations.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Amitriptyline and Amoxapine together?
Using amitriptyline and amoxapine together can add up their effects on your heart's rhythm, so this combination is best avoided; if you are on both, ask your pharmacist or doctor, who can monitor you and adjust your treatment. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Amitriptyline and Amoxapine 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 Amoxapine interaction managed?
These two antidepressants are rarely used together, but if your care team has prescribed both, this is manageable. Keep taking both exactly as prescribed unless your doctor tells you otherwise. Your team may monitor you more closely, which can include checking your heart rhythm (ECG) and blood electrolytes like potassium and magnesium. Doses may need to be adjusted and individualized by your care… 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 Amoxapine 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: amitriptyline HCl oral tablet, amitriptyline HCl oral tablet. RemedyRepack Inc. (per DailyMed), Indiana, PA, 2010. DailyMed
Keep reading about Amitriptyline
Keep reading about Amoxapine
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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