Amitriptyline and Pixantrone: 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
Pixantrone
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.
These two medicines can interact. Pixantrone (a cancer medicine) can slow down one of the liver enzymes (called CYP1A2) that helps break down amitriptyline (Elavil). When that enzyme is slowed, amitriptyline can build up in your body more than usual.
Higher levels can mean stronger side effects, like drowsiness, dizziness, dry mouth, constipation, a fast heartbeat, or feeling foggy. The good news is that this concern is based on how the drugs work in theory, not on strong real-world reports. Your care team can manage it by adjusting your dose if needed and watching you a little more closely. Keep taking both as prescribed and talk with your pharmacist or doctor.
Effect: Pixantrone inhibits CYP1A2, the enzyme partly responsible for amitriptyline metabolism, so co-administration may increase amitriptyline exposure (higher AUC/Cmax).
Direction: Increased tricyclic exposure, raising risk of anticholinergic effects, sedation, orthostasis, and QT/conduction effects.
- Mechanism: CYP1A2 inhibition by pixantrone (amitriptyline is a substrate, not a prodrug).
- Evidence: Theoretical.
- Onset: Unspecified.
- Severity: Major (labeled).
- Management: If used together, monitor closely for TCA toxicity; dose may need individualization. Consider ECG and clinical review; plasma level monitoring where available.
What happens
Increased CYP1A2 substrate exposure
Interaction Deep Dive
Exercise caution when pixantrone, which inhibits CYP1A2, is given alongside a CYP1A2 substrate, since this combination can raise the exposure of the CYP1A2 substrate. Should co-administration be necessary, close patient monitoring is advised1.
Why it happens (mechanism)
Inhibition of CYP1A2-mediated metabolism by pixantrone
How to manage this interaction
If your care team decides you need both, here is how they typically handle it:
- Keep taking both as prescribed unless your doctor tells you otherwise. Do not stop or change anything on your own.
- Closer monitoring: Your team may watch you more closely for signs that amitriptyline is building up, such as strong drowsiness, dizziness, dry mouth, constipation, or a rapid or irregular heartbeat.
- Dose tailoring: Your amitriptyline dose may need to be adjusted and individualized by your care team.
Tell your pharmacist or prescriber about any new or worsening side effects, and confirm your full medication list so they can plan the safest approach.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Amitriptyline and Pixantrone together?
Pixantrone may slow the breakdown of amitriptyline, raising its levels and side effect risk; this is a theoretical concern that your care team can manage with closer monitoring and dose adjustment. Keep taking both as prescribed and report new side effects. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Amitriptyline and Pixantrone 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 Pixantrone interaction managed?
If your care team decides you need both, here is how they typically handle it: Keep taking both as prescribed unless your doctor tells you otherwise. Do not stop or change anything on your own. Closer monitoring: Your team may watch you more closely for signs that amitriptyline is building up, such as strong drowsiness, dizziness, dry mouth, constipation, or a rapid or irregular heartbeat. Dose ta… 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 Pixantrone 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: Pixuvri intravenous injection powder concentrate, pixantrone intravenous injection powder concentrate. CTI Life Sciences Limited (per EMA), Hertforshire, United Kingdom, 2012.
Keep reading about Amitriptyline
Keep reading about Pixantrone
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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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