Drug & supplement interaction

Cinchona + Naproxen, Pseudoephedrine

Naproxen, Pseudoephedrine brand name: Aleve Cold and Sinus.

Moderate Interaction
The bottom line Moderate

Cinchona has a moderate interaction with Naproxen, Pseudoephedrine. 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 Naproxen, Pseudoephedrine

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

Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

Why this applies to Naproxen, Pseudoephedrine

Naproxen, Pseudoephedrine 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 gist with Aleve Cold and Sinus, which pairs naproxen (an anti-inflammatory pain reliever) with pseudoephedrine (a decongestant). Naproxen on its own can already irritate the stomach lining and make it a little harder for your blood to clot. Lab studies suggest the alkaloids in cinchona bark (quinine, quinidine, cinchonine) can also keep platelets from sticking together, so stacking the two could, in theory, nudge your bleeding risk up a bit higher.

To be honest, this is a theoretical concern based on test-tube data, not real-world reports, so I wouldn't panic. Still, watch for easy bruising, nosebleeds, dark stools, or stomach upset. Cinchona bark itself can be risky, so please run this combo by your pharmacist or doctor first.

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 Naproxen, Pseudoephedrine 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 Cinchona

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

Everything else you take

See Every Supplement That Interacts With Naproxen, Pseudoephedrine

This page covers Cinchona only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Naproxen, Pseudoephedrine page lists 334 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Beer (major), Danshen (major) and Ephedra (major).

By severity: 11 major · 279 moderate · 44 minor.

From our pharmacist’s overview on the Naproxen, Pseudoephedrine page

“Aleve Cold and Sinus pairs naproxen, an anti-inflammatory painkiller, with pseudoephedrine, a decongestant that acts as a mild stimulant, and that combination is why its supplement list runs to 334 entries and deserves real vigilance. The two biggest themes mirror the two drugs.”

Reviewed by 2 · Jul 18, 2026

Open the Naproxen, Pseudoephedrine 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 Naproxen, Pseudoephedrine 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 Naproxen, Pseudoephedrine 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

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

29 days ago today
Medication Naproxen, Pseudoephedrine
Steady interest

#1,599 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
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
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
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 Cinchona and Naproxen, Pseudoephedrine Together: Common Questions

Can you take Cinchona with Naproxen, Pseudoephedrine?
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 Naproxen, Pseudoephedrine 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.