Amitriptyline and Abiraterone Acetate: 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
Abiraterone Acetate
Amitriptyline
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.
Let me explain how these two work together. Abiraterone (used for prostate cancer) can slow down a liver enzyme called CYP2D6, which is the same pathway your body uses to break down amitriptyline. When that breakdown slows, more amitriptyline can build up in your system than expected.
Because of this, you might notice more of amitriptyline's usual side effects, like drowsiness, dry mouth, constipation, or feeling lightheaded. This is a theoretical concern, meaning it's based on how the drugs work rather than lots of real-world reports. Please don't change anything on your own. Your care team can manage this easily by watching you and adjusting your dose if needed.
Effect: Increased amitriptyline exposure via abiraterone inhibition of CYP2D6, the primary enzyme clearing amitriptyline (a CYP2D6 substrate). Neither agent is prodrug-dependent here, so inhibition raises parent drug levels and TCA-related effects.
- Direction: Higher amitriptyline AUC/Cmax; poor metabolizers at greatest risk.
- Onset: Unspecified.
- Evidence: Theoretical; magnitude not quantified.
- Management: Use with caution. Monitor for anticholinergic and cardiac effects (sedation, orthostasis, QT/ECG). Consider therapeutic plasma level monitoring and dose adjustment as needed. If abiraterone is stopped, an amitriptyline dose increase may be warranted.
What happens
Increased exposure of amitriptyline
Interaction Deep Dive
When amitriptyline (a substrate of CYP2D6) is taken together with an inhibitor of CYP2D6, amitriptyline exposure may rise. This risk is particularly pronounced in poor metabolizers. Caution and close patient monitoring are warranted whenever the two must be given together. Plasma concentrations of amitriptyline should also be checked, with dose adjustment as necessary. Should the CYP2D6 inhibitor be stopped, the amitriptyline dose may need to be raised1.
Why it happens (mechanism)
Inhibition of CYP2D6-mediated metabolism of amitriptyline
How to manage this interaction
Good news: this is manageable when your care team knows you take both.
- Keep taking both exactly as prescribed unless your doctor or pharmacist tells you otherwise.
- Your team may monitor you more closely for amitriptyline side effects such as drowsiness, dry mouth, constipation, or dizziness.
- They may check amitriptyline blood levels and adjust the dose to keep it in a safe range.
- If the abiraterone is later stopped, your amitriptyline dose may need to be adjusted again.
Tell your pharmacist or prescriber about any new or worsening side effects.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Amitriptyline and Abiraterone Acetate together?
Abiraterone can raise amitriptyline levels by slowing its breakdown, so your team may monitor you and check blood levels, adjusting the amitriptyline dose as needed. 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 Abiraterone Acetate interaction?
It is rated moderate. Can be significant — usually manageable with 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 Abiraterone Acetate interaction managed?
Good news: this is manageable when your care team knows you take both. Keep taking both exactly as prescribed unless your doctor or pharmacist tells you otherwise. Your team may monitor you more closely for amitriptyline side effects such as drowsiness, dry mouth, constipation, or dizziness. They may check amitriptyline blood levels and adjust the dose to keep it in a safe range. If the abirateron… 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 Abiraterone Acetate 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 anything you'd monitor while I'm on both?
References (1)
- Product Information: amitriptyline HCl oral tablet, amitriptyline HCl oral tablet. RemedyRepack Inc. (per DailyMed), Indiana, PA, 2010. DailyMed
Keep reading about Abiraterone Acetate
Keep reading about Amitriptyline
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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