Drug & supplement interaction

Fever Bark + Aprocitentan

Aprocitentan brand name: Tryvio.

Moderate Interaction
The bottom line Moderate

Aprocitentan falls into 2 drug categories that Fever Bark can interact with; the most serious is rated moderate. Theoretically, fever bark might alter the effects of antihypertensive drugs.

Read the full interaction report
SeverityModerate
LikelihoodProbable
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Fever Bark and Aprocitentan

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Fever Bark interacts with whole categories of medication. Aprocitentan falls into 2 of those categories, so it can interact with Fever Bark in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

ANTIHYPERTENSIVE DRUGS

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Why this applies to Aprocitentan

Aprocitentan falls under ANTIHYPERTENSIVE DRUGS — the group Fever Bark interacts with.

Theoretically, fever bark might alter the effects of antihypertensive drugs.
Yohimbine, a constituent of fever bark, is an alpha-2 adrenoceptor antagonist and has been reported to increase blood pressure in clinical research. Conversely, reserpine can reduce both systolic and diastolic blood pressure. Theoretically, concomitant use of fever bark and antihypertensive drugs can interfere with blood pressure control.
Severity Moderate Likelihood Probable Evidence D

Interaction 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..

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

Here's the thing to know if you're taking Tryvio (aprocitentan) for high blood pressure and thinking about fever bark. This isn't really about how your body breaks down the drug. Aprocitentan isn't a prodrug, so nothing here changes its activation. The concern is a tug-of-war on your actual blood pressure numbers.

Fever bark carries a mix of plant alkaloids that pull in opposite directions. The yohimbine-like ones can raise blood pressure, which could work against aprocitentan and leave your pressure less controlled. The reserpine-like ones can lower it, which stacked on top of your medicine could drop you too far, causing dizziness, swelling, or fatigue. This is theoretical, based on pharmacology rather than solid human studies, but the effect is unpredictable. Please check with your pharmacist or doctor before combining them.

References
  1. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  2. Kearney T, Tu N, Haller C. Adverse drug events associated with yohimbine-containing products: a retrospective review of the California Poison Control System reported cases. Ann Pharmacother 2010;44:1022-9. PubMed
  3. Lobay D. Rauwolfia in the Treatment of Hypertension. Integr Med (Encinitas). 2015 Jun;14(3):40-6.
  4. Sheldon MB, Kotte JH. Effect of Rauwolfia serpentina and reserpine on the blood pressure in essential hypertension; a long-term double-blind study. Circulation. 1957 Aug;16(2):200-6.
Moderate

CYTOCHROME P450 3A4 (CYP3A4) INHIBITORS

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Aprocitentan also falls under CYTOCHROME P450 3A4 (CYP3A4) INHIBITORS.

Theoretically, CYP3A4 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 CYP3A4 enzymes.
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 thing to understand with this pairing: it's actually the fever bark that may be affected, not your blood pressure medicine. Aprocitentan (Tryvio) can act as a mild CYP3A4 inhibitor, and one of the alkaloids in fever bark, yohimbine, is broken down by that same CYP3A4 enzyme. So in theory, slowing that pathway could let yohimbine build up in your system.

Why does that matter? Yohimbine can raise blood pressure and heart rate and cause jitteriness or anxiety, which is a strange direction to go when you're taking Aprocitentan specifically to lower stubborn high blood pressure. I'll be honest, this is a theoretical concern based on how the drugs work, not proven cases. Still, fever bark is a risky supplement on its own, so please check with your pharmacist or doctor before combining them.

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. 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 Aprocitentan one above is among 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.

Everything else you take

See Every Supplement That Interacts With Aprocitentan

This page covers Fever Bark only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Aprocitentan page lists 189 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Beer (major) and Siberian Cocklebur (major).

By severity: 7 major · 161 moderate · 21 minor.

From our pharmacist’s overview on the Aprocitentan page

“Aprocitentan (Tryvio) is prescribed when blood pressure stays high despite other medicines, so anything that pushes your pressure around cuts straight to why you take it. Most of the 189 ingredients here do exactly that: some add to the drop and can leave you dizzy or faint, while others, tyramine among them, push pressure back up and…”

Reviewed by 2 · Jul 18, 2026

Open the Aprocitentan interaction page

How much people look this up

Where Fever Bark and Aprocitentan 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
Steady interest

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

29 days ago today
Medication Aprocitentan
Top 25%

#469 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 Aprocitentan

What Is Aprocitentan Used For?

Brand name: Tryvio

Tryvio is used to treat high blood pressure (hypertension) in adults. It is specifically for people whose blood pressure is not adequately controlled on other blood pressure medications — it is always used together with at least one other antihypertensive drug, not on its own.

Lowering blood pressure helps reduce the risk of serious cardiovascular events such as stroke and heart attack. Tryvio has not been studied as a standalone treatment and is not intended to replace other blood pressure medicines.

See full Aprocitentan 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

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Pharmacist Counseling Corner

Taking Fever Bark and Aprocitentan Together: Common Questions

Can you take Fever Bark with Aprocitentan?
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.
Why are there 2 interactions listed for Fever Bark and Aprocitentan?
Aprocitentan belongs to more than one drug category, and Fever Bark interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Fever Bark and Aprocitentan 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

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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.