Drug Interaction Report

Abiraterone and Dextromethorphan: Interaction Details

A pharmacist-reviewed analysis of the Abiraterone and Dextromethorphan interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Dextromethorphan

Delsym
+

Abiraterone

Abirtega Yonsa Zytiga Zytiga®
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
LinkedIn
Interaction severity
Moderate
Can be significant — usually manageable with monitoring.
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.

Of 164 documented Abiraterone interactions, 14 are rated moderate — including this one.
Onset
unspecified
Evidence
probable
Severity
Moderate

What happens

Increased dextromethorphan exposure

Interaction Deep Dive

Coadministration of abiraterone acetate (a CYP2D6 inhibitor) with dextromethorphan (a CYP2D6 substrate) may result in increased plasma concentrations of dextromethorphan. When abiraterone acetate (1000 mg/day) and predniSONE (5 mg twice daily) were administered with dextromethorphan (30 mg), the dextromethorphan Cmax and AUC were increased 2.8-fold and 2.9-fold, respectively. If an alternative to dextromethorphan cannot be used, use caution and reduce dextromethorphan dose as necessary during coadministration21.

Why it happens (mechanism)

Inhibition of CYP2D6-mediated dextromethorphan metabolism by abiraterone acetate

Literature reports

1 report — tap to read

a) The administration of abiraterone acetate 1000 mg/day (plus prednisone 5 mg twice daily) with dextromethorphan 30 mg increased the dextromethorphan Cmax and AUC 2.8-fold and 2.9-fold, respectively. There was also a 1.3-fold increase in the AUC of dextrorphan (active metabolite of dextromethorphan) 21.

Common questions

Can I take Abiraterone and Dextromethorphan together?

Increased dextromethorphan exposure Always confirm with your pharmacist or prescriber before making any change.

How serious is the Abiraterone and Dextromethorphan 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 strong is the evidence for this interaction?

The evidence is graded "probable". Good supporting evidence, though not definitively proven.

From our Q&A

Real reader questions about these medications, each personally answered by our pharmacist:

Questions for your pharmacist

  • Does my dose of Abiraterone or Dextromethorphan 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 (2)

  1. Product Information: AKEEGA(TM) oral tablets, niraparib, abiraterone acetate oral tablets. Janssen Biotech, Inc. (per FDA), Horsham, PA, 2023. DailyMed
  2. Product Information: ZYTIGA(R) oral tablets, abiraterone acetate oral tablets. Janssen Biotech, Inc. (per FDA), Horsham, PA, 2013. DailyMed
Was this write-up helpful?
Dextromethorphan

Keep reading about Dextromethorphan

All Dextromethorphan interactions (20)
Also serious with: Linezolid Injection Palonosetron Injection Amitriptyline Buprenorphine
Abiraterone

Keep reading about Abiraterone

All Abiraterone interactions (164) Abiraterone drug information
Also serious with: Ensitrelvir Abametapir Acarbose Albiglutide
Beyond drug–drug

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:

Dextromethorphan + Activated Charcoal Grapefruit Lithium St. John's Wort 1,3-dmaa 5-htp Acacia Rigidula Acetyl-l-carnitine + 163 more
Abiraterone + Activated Charcoal Beer Grapefruit Siberian Cocklebur St. John's Wort Wine Acacia Rigidula Adrafinil + 173 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

Check another combination

Our instant two-drug interaction checker is almost here.

Coming soon

The instant two-drug checker is on its way.

In the meantime, browse the directory below to look up any drug and see its documented interactions.

Still have questions about this combination?

Every question gets a real answer from a licensed pharmacist — free, and usually within a day.

Ask the pharmacist
This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.