Drug & supplement interaction

Fever Bark + Abiraterone Acetate

Abiraterone Acetate brand names: Zytiga, Yonsa.

Moderate Interaction
The bottom line Moderate

Fever Bark has a moderate interaction with Abiraterone Acetate. Theoretically, CYP2D6 inhibitors might increase the levels and clinical effects of yohimbine, a constituent of fever bark.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Interaction report

Fever Bark and Abiraterone Acetate

Here is the interaction we found between these two, with the evidence behind it.

Moderate

CYTOCHROME P450 2D6 (CYP2D6) INHIBITORS

Why this applies to Abiraterone Acetate

Abiraterone Acetate falls under CYTOCHROME P450 2D6 (CYP2D6) INHIBITORS — the group Fever Bark interacts with.

Theoretically, CYP2D6 inhibitors might increase the levels and clinical effects of yohimbine, a constituent of fever bark.
In vitro and clinical research shows that the fever bark constituent, yohimbine, is metabolized by CYP2D6 isoenzymes.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the key thing to understand: your prostate cancer medicine, abiraterone (Yonsa), actually blocks an enzyme called CYP2D6. Fever bark contains yohimbine, and yohimbine relies on that very same enzyme to be cleared from your body. So when abiraterone slows that enzyme down, yohimbine can build up and hit harder than expected.

What does that look like in real life? More of yohimbine's stimulant-type effects, things like a racing heart, jitteriness, anxiety, and swings in blood pressure. To be fair, this is a theoretical concern based on how these chemicals behave, not on solid human studies. Still, fever bark is potent and poorly studied, so I'd steer clear while on abiraterone. Please run it by your pharmacist or oncologist first.

References
  1. Le Corre P, Parmer RJ, Kailasam MT, et al. Human sympathetic activation by alpha2-adrenergic blockade with yohimbine: Bimodal, epistatic influence of cytochrome P450-mediated drug metabolism. Clin Pharmacol Ther. 2004;76(2):139-53.
  2. Mueller-Schoell A, Michelet R, Weinelt F, Kloft C, Mikus G. CYP2D6 phenotype explains reported yohimbine concentrations in four severe acute intoxications. Arch Toxicol. 2021. PubMed
  3. Bharucha AE, Skaar T, Andrews CN, et al Relationship of cytochrome P450 pharmacogenetics to the effects of yohimbine on gastrointestinal transit and catecholamines in healthy subjects. Neurogastroenterol Motil. 2008;20(8):891-9. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Fever Bark Also Interacts With Other Medications

Fever Bark has 40 major, 673 moderate, 87 minor known drug interactions in our database — the Abiraterone Acetate one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Fever Bark

Covers the 2,830 medications we’ve checked against Fever Bark. Pick one to open its full report.

From our Q&A

Questions About Fever Bark or Abiraterone Acetate

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Fever Bark or Abiraterone Acetate, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Abiraterone Acetate

This page covers Fever Bark only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Abiraterone Acetate page lists 171 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 128 moderate · 37 minor.

From our pharmacist’s overview on the Abiraterone Acetate page

“Six of the 171 supplement and herbal interactions on file for abiraterone acetate (Zytiga, Yonsa) are rated major, and with an advanced prostate cancer treatment there is little margin for a drug level that drifts, so these pairings deserve genuine care. The bulk of the list, 121 ingredients, affects the CYP3A4 enzyme that clears abira…”

Reviewed by 2 · Jul 18, 2026

Open the Abiraterone Acetate interaction page

How much people look this up

Where Fever Bark and Abiraterone Acetate Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Fever Bark
Top half

#565 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Abiraterone Acetate
Top 10%

#275 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Fever Bark

What is Fever Bark?

Fever Bark
  • Fever
  • Diarrhea
  • Malaria (traditional)
  • Digestive complaints
  • Bitter tonic

Fever bark is the bark of the Australian tree Alstonia constricta, used in traditional medicine for fever, diarrhea, and infections. There is very little reliable human research to support these uses, and the bark contains potent alkaloids that may cause serious side effects. It is best avoided unless used under direct medical supervision.

Read the full Fever Bark monograph & all interactions
Medication

About Abiraterone

What Is Abiraterone Used For?

Brand names: Zytiga, Yonsa

Abiraterone acetate tablets are used to treat two types of advanced prostate cancer: metastatic castration-resistant prostate cancer (CRPC — cancer that has spread and keeps growing despite low testosterone levels) and metastatic high-risk castration-sensitive prostate cancer (CSPC — cancer that has spread but still responds to hormone-lowering treatment). It is always taken together with a corticosteroid — most products pair with prednisone, while Yonsa is specifically indicated with methylprednisolone.

All products — including Abiraterone, Abiraterone Acetate, Abirtega, Yonsa, and Zytiga — are taken by mouth as a tablet. Yonsa is approved only for metastatic CRPC, while the other products (Abiraterone, Abiraterone Acetate, Abirtega, and Zytiga) are approved for both metastatic CRPC and metastatic high-risk CSPC.

See full Abiraterone drug information
Keep checking

Other Drugs & Fever Bark

Browse every other medication we’ve checked against Fever Bark — both the ones with a known interaction and the ones without. Select any drug for the full detail.

40Major
673Moderate
87Minor
2,029No known interaction
Major

40 interactions

Moderate

673 interactions

Showing 60 of 673 moderate interactions — see all 673 on the Fever Bark page.

Minor

87 interactions

Showing 60 of 87 minor interactions — see all 87 on the Fever Bark page.

No interaction 2,029 drugs checked — show the list
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Pharmacist Counseling Corner

Taking Fever Bark and Abiraterone Acetate Together: Common Questions

Can you take Fever Bark with Abiraterone Acetate?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Fever Bark and Abiraterone Acetate interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Abiraterone Acetate and Fever Bark?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.