Drug & supplement interaction

Cinchona + Apixaban

Apixaban brand name: Eliquis.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Cinchona has a moderate interaction with Apixaban. Theoretically, taking cinchona might increase the drug effects and risk of bleeding with anticoagulant and antiplatelet drugs.

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

Cinchona and Apixaban

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

Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

Why this applies to Apixaban

Apixaban falls under ANTICOAGULANT/ANTIPLATELET DRUGS — the group Cinchona interacts with.

Theoretically, taking cinchona might increase the drug effects and risk of bleeding with anticoagulant and antiplatelet drugs.
In vitro evidence shows that the alkaloids quinine, quinidine, and cinchonine, constituents of cinchona, inhibit platelet aggregation.
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 concern with pairing cinchona bark with Eliquis (apixaban). Apixaban already thins your blood to stop dangerous clots, and it works as-is, so it isn't a prodrug that needs activating. The worry here is additive. Lab studies suggest cinchona's compounds (quinine, quinidine, and cinchonine) can make platelets, the cells that help blood clot, less sticky. Stack that on top of apixaban and you may tip toward too much blood thinning.

In plain terms, that could mean easier bruising, nosebleeds, bleeding gums, or harder-to-stop bleeding. I'll be honest though: this is theoretical, based mostly on test-tube data, not strong human studies. Still, since cinchona supplements are unpredictable and risky on their own, please check with your pharmacist or doctor before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  2. Shah BH, Nawaz Z, Virani SS, Ali IQ, Saeed SA, Gilani AH.The inhibitory effect of cinchonine on human platelet aggregation due to blockade of calcium influx. Biochem Pharmacol 1998;56:955-60. 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

Cinchona Also Interacts With Other Medications

Cinchona has 3 major, 472 moderate, 16 minor known drug interactions in our database — the Apixaban one above is one of them. If you take anything else, check it against the full list below.

Major 3 Moderate 472 Minor 16 No known interaction 2,339 (incl. Apixaban)
Taking anything else?

Check Another of Your Medications Against Cinchona

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

From our Q&A

Questions About Cinchona or Apixaban

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Cinchona or Apixaban, 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 Apixaban

This page covers Cinchona only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Apixaban page lists 285 supplements it has a documented interaction with, worst first, each one explained.

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

By severity: 5 major · 240 moderate · 40 minor.

From our pharmacist’s overview on the Apixaban page

“St. John's wort can weaken apixaban (Eliquis), speeding how the body clears this blood thinner and leaving you less protected from the strokes and clots it is prescribed to prevent.”

Reviewed by 2 · Jul 18, 2026

Open the Apixaban interaction page

One more smart check

Taking Cinchona as Part of a Dietary Supplement Product? Check It for Interactions

We hold 12 real supplement products containing Cinchona, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cinchona. Your product may carry other ingredients that interact with Apixaban too, on top of Cinchona — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Cinchona and Apixaban 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 Cinchona
Steady interest

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

29 days ago today
Medication Apixaban
Most looked up

#1 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 Cinchona

What is Cinchona?

Cinchona
  • Malaria (historical/traditional)
  • Fever
  • Leg cramps and restless legs
  • Digestive upset and loss of appetite
  • Bitter tonic

Cinchona bark is the natural source of quinine and has been used for centuries to treat malaria and fever, but the bark itself is not standardized and can be unpredictable and risky. Modern medicine uses purified, dose-controlled quinine instead, and the supplement form carries real dangers, including serious heart and blood problems. Talk to a pharmacist or doctor before using it, and avoid it during pregnancy.

Read the full Cinchona monograph & all interactions
Medication

About Apixaban

What Is Apixaban Used For?

Brand name: Eliquis

Apixaban is used to reduce the risk of stroke and dangerous clots traveling through the body in adults with nonvalvular atrial fibrillation (an irregular heart rhythm not caused by a heart valve problem). It is also used to prevent deep vein thrombosis (DVT — a blood clot in the leg) in adults after hip or knee replacement surgery, and to treat DVT and pulmonary embolism (PE — a blood clot in the lungs) in adults, including reducing the risk of those clots coming back.

Eliquis (the brand-name tablet and kit) is additionally approved to treat venous thromboembolism (VTE — blood clots in the veins) and reduce the risk of recurrent VTE in pediatric patients from birth and older, after at least 5 days of initial anticoagulant treatment. The generic apixaban tablet carries the adult indications only.

See full Apixaban drug information
Keep checking

Other Drugs & Cinchona

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

3Major
472Moderate
16Minor
2,338No known interaction
3 Major 472 Moderate 16 Minor 2,338 No interaction
Major

3 interactions

Moderate

472 interactions

Showing 60 of 472 moderate interactions — see all 472 on the Cinchona page.

Minor

16 interactions

No interaction 2,338 drugs checked — show the list

We also checked Cinchona against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,338 medications checked with no known interaction — see the full Cinchona list.

See the full Cinchona interactions page
See every supplement checked against Apixaban, ranked by severity
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
Cinchona monograph › Uses, safety, and every drug interaction in one place Apixaban supplement interactions › Every supplement checked against Apixaban, ranked by severity Apixaban drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Cinchona and Apixaban Together: Common Questions

Can you take Cinchona with Apixaban?
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 Cinchona and Apixaban 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 Apixaban and Cinchona?

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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.