Drug & supplement interaction

Danshen + Quinidine

Quinidine brand names: Quinaglute Duratabs, Quinaglute, Duraquin, Cardioquin, Cin-Quin, and others.

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

Quinidine falls into 2 drug categories that Danshen can interact with; the most serious is rated moderate. Danshen might alter the levels of drugs cleared by p-glycoprotein.

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

Danshen and Quinidine

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

Why Are There 2 Interactions?

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

Moderate

P-GLYCOPROTEIN SUBSTRATES

1 of 2

Why this applies to Quinidine

Quinidine falls under P-GLYCOPROTEIN SUBSTRATES — the group Danshen interacts with.

Danshen might alter the levels of drugs cleared by p-glycoprotein.
Pharmacokinetic research in healthy volunteers suggests that danshen might affect p-glycoprotein activity. Taking danshen extract 1 gram three times daily for 10 days prior to receiving fexofenadine 60 mg increases peak levels of fexofenadine, a p-glycoprotein substrate, by 27.4% and area under the curve (AUC) by 37.2%.
Severity Moderate Likelihood Possible Evidence B

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 situation with these two. Your body uses a kind of cellular pump called p-glycoprotein to move quinidine around and help clear it. Danshen appears to slow that pump down. In a study with a similar pumped drug, danshen pushed peak blood levels up by about 27% and overall exposure by about 37%. So the worry is that adding danshen could let more quinidine build up in your system.

Why that matters here: quinidine is a heart rhythm drug with a narrow safe range, and higher levels can cause ringing in the ears, nausea, dizziness, or dangerous rhythm changes. On top of that, danshen itself can thin the blood a bit. Please don't start or stop anything on your own. Check with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Qiu F, Zeng J, Liu S, He M, Zhu L, Ye Y, Miao P, Shen S, Jiang J. Effects of danshen ethanol extract on the pharmacokinetics of fexofenadine in healthy volunteers. Evid Based Complement Alternat Med. 2014;2014:473213. PubMed
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 2

Quinidine also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Danshen might alter the levels and clinical effects of drugs metabolized by CYP3A4.
Preliminary clinical research in healthy males shows that the administration of danshen for 10-14 days induces intestinal CYP3A4 and increases the clearance of midazolam, a CYP3A4 substrate. The maximum concentration of midazolam was decreased by 31% to 67%, and drug levels were decreased by 27% to 80%. However, a single dose of danshen has the opposite effect, increasing maximum concentrations of midazolam by 87%.
Severity Moderate Likelihood Possible Evidence B

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 quinidine: your body partly clears it using a liver and gut enzyme called CYP3A4. Danshen seems to nudge this enzyme in two directions depending on timing. In one small human study, taking danshen for about 10 to 14 days actually sped up that enzyme, which could lower your quinidine levels and let your irregular heartbeat slip back. But a single dose of danshen did the opposite, raising drug levels, which with quinidine could mean more side effects like nausea, ringing in the ears, dizziness, or even new rhythm problems.

Because quinidine is a heart rhythm drug where small shifts matter, I wouldn't pair it with danshen without checking first. Please run it by your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Qiu F, Wang G, Zhang R, Sun J, et al. Effect of danshen extract on the activity of CYP3A4 in healthy volunteers. Br J Clin Pharmacol 2010;69:656-62. PubMed
  2. Qiu F, Jiang J, Ma Y, Wang G, Gao C, Zhang X, Zhang L, Liu S, He M, Zhu L, Ye Y, Li Q, Miao P. Opposite Effects of Single-Dose and Multidose Administration of the Ethanol Extract of Danshen on CYP3A in Healthy Volunteers. Evid Based Complement Alternat Me 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

Danshen Also Interacts With Other Medications

Danshen has 123 major, 935 moderate known drug interactions in our database — the Quinidine one above is among them. If you take anything else, check it against the full list below.

Major 123 Moderate 935 No known interaction 1,772 (incl. Quinidine)
Taking anything else?

Check Another of Your Medications Against Danshen

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

From our Q&A

Questions About Danshen or Quinidine

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

This page covers Danshen only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Quinidine page lists 207 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Beer (major) and Cesium (major).

By severity: 15 major · 157 moderate · 35 minor.

From our pharmacist’s overview on the Quinidine page

“Grapefruit belongs nowhere near quinidine. The juice blocks the main enzyme that clears this heart rhythm medicine, so quinidine levels can climb into dangerous territory, and it leads a list of 207 supplement and herbal ingredients I would treat with real seriousness, 15 of them rated major.”

Reviewed by 2 · Jul 18, 2026

Open the Quinidine interaction page

One more smart check

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

We hold 18 real supplement products containing Danshen, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Danshen. Your product may carry other ingredients that interact with Quinidine too, on top of Danshen — 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 Danshen and Quinidine 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 Danshen
Top half

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

29 days ago today
Medication Quinidine
Top 25%

#353 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 Danshen

What is Danshen?

Danshen
  • Heart and circulation support
  • Angina (chest pain)
  • High blood pressure
  • Anxiety and stress
  • Liver health

Danshen is a root used in traditional Chinese medicine, mainly for heart and circulation problems. Some early research is promising, but the evidence is not strong enough to confirm it works for any condition, and it may affect blood clotting. Talk to a pharmacist or doctor before using it, especially if you take other medicines or have a health condition.

Read the full Danshen monograph & all interactions
Medication

About Quinidine

What Is Quinidine Used For?

Brand names: Quinaglute Duratabs, Quinaglute, Duraquin, Cardioquin, Cin-Quin, Quinora, Lin-Qin, Quinova, Quinidex Extentabs

Quinidine is used to help restore a normal heart rhythm in people with atrial fibrillation or atrial flutter (irregular, rapid heart rhythms originating in the upper chambers). It is also used on an ongoing basis to reduce how often those episodes come back, in patients whose episodes are frequent and poorly tolerated — but only after other options have been tried first.

Quinidine sulfate oral tablets and quinidine gluconate extended-release oral tablets are both approved for these heart-rhythm uses. Quinidine sulfate tablets are additionally used as part of an approved treatment regimen for life-threatening Plasmodium falciparum malaria, in combination with quinidine gluconate injection (the central component of that regimen). Both formulations may also be used to suppress recurrent, documented life-threatening ventricular arrhythmias (dangerous rapid rhythms in the lower chambers of the heart), such as sustained ventricular tachycardia.

See full Quinidine drug information
Keep checking

Other Drugs & Danshen

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

123Major
935Moderate
0Minor
1,771No known interaction
123 Major 935 Moderate 1,771 No interaction
Major

123 interactions

Showing 60 of 123 major interactions — see all 123 on the Danshen page.

Moderate

935 interactions

Showing 60 of 935 moderate interactions — see all 935 on the Danshen page.

No interaction 1,771 drugs checked — show the list

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

Showing the 60 most looked-up of 1,771 medications checked with no known interaction — see the full Danshen list.

See the full Danshen interactions page
See every supplement checked against Quinidine, 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
Danshen monograph › Uses, safety, and every drug interaction in one place Quinidine supplement interactions › Every supplement checked against Quinidine, ranked by severity Quinidine 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 Danshen and Quinidine Together: Common Questions

Can you take Danshen with Quinidine?
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 Danshen and Quinidine?
Quinidine belongs to more than one drug category, and Danshen 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 Danshen and Quinidine 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 Quinidine and Danshen?

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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.