Drug & supplement interaction

Plant Sterols + Quinidine

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

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Plant Sterols and Quinidine in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Plant Sterols and Quinidine

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Quinidine and Plant Sterols in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

Worth understanding: our licensed dataset holds no drug-interaction record for Plant Sterols at all — not against Quinidine, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Plant Sterols safety at a glance

Plant Sterols overall Generally safe Generally well tolerated at typical food and supplement amounts for most adults.
Pregnancy Use caution Safety of concentrated supplements during pregnancy is not well studied, so use caution and check with your doctor.
Breastfeeding Use caution There is limited information on concentrated supplements during breastfeeding, so caution is advised.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Quinidine and Plant Sterols? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Plant Sterols and Quinidine May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Diarrhea Additional detail

    Plant Sterols

    “Abdominal discomfort has occurred in one child in a clinical trial of oral plant sterols. Because plant sterols decrease cholesterol absorption in the gut, there is concern that they might produce some gastrointestinal symptoms like diarrhea and excess amounts of fat in the stool (steatorrhea), although these adverse effects have not been reported in clinical research.”

    Plant Sterols · Natural Medicines adverse-effect record, reported in diarrhea.

    1 source cited
    1. 35106. Guardamagna, O., Abello, F., Baracco, V., Federici, G., Bertucci, P., Mozzi, A., Mannucci, L., Gnasso, A., and Cortese, C. Primary hyperlipidemias in children: effect of plant sterol supplementation on plasma lipids and markers of cholesterol synthesis a

    Quinidine

    Listed in the ADVERSE REACTIONS section of the FDA label for Quinidine. Read the label on DailyMed ›

  • A skin rash Additional detail

    Plant Sterols

    “Acute dermatitis has been reported in a case report of a 51-year-old female who used a pharmacy-brand plant sterol supplement to lower cholesterol levels. The rash was widespread with lesions on the hands and feet and a red and swollen face. The patient was treated orally with prednisolone and topically with emollients for 2 weeks.”

    Plant Sterols · Natural Medicines adverse-effect record, reported in dermatitis.

    1 source cited
    1. 90737. Haque Hussain SS, Weir J, Roberts N. Severe dermatitis secondary to plant sterol supplements. Clin Exp Dermatol. 2009 Oct;34(7):e276-7. PubMed

    Quinidine

    Listed in the ADVERSE REACTIONS section of the FDA label for Quinidine. Read the label on DailyMed ›

Reported for Plant Sterols but not commonly for Quinidine: stomach upset and acne.

Effects for Quinidine come from the ADVERSE REACTIONS section of its FDA label; effects for Plant Sterols come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

From our Q&A

Questions About Plant Sterols 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 Plant Sterols 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 Plant Sterols 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 Plant Sterols as Part of a Dietary Supplement Product? Check It for Interactions

We hold 28 real supplement products containing Plant Sterols, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Plant Sterols. Even though Plant Sterols itself has no known interaction with Quinidine, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Plant Sterols 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 Plant Sterols
Steady interest

#1,091 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Quinidine
Top half

#1,338 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Plant Sterols reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Plant Sterols and Quinidine records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Plant Sterols

What is Plant Sterols?

  • High cholesterol
  • Heart health support
  • Lowering LDL cholesterol

Plant sterols (and their close relatives, plant stanols) are natural compounds found in plants that can modestly lower LDL ('bad') cholesterol when taken regularly in adequate amounts, usually through fortified foods or supplements. They are widely considered a useful add-on to a heart-healthy diet, but they are not a replacement for prescribed cholesterol medicine. Talk with your pharmacist or doctor before starting them, especially if you take cholesterol drugs.

Sterols extracted from plant oils, nuts, seeds, grains, and legumes · Capsules, softgels, fortified margarine/spreads, fortified yogurt and milk, powders

An interaction check asks whether these two react with each other — it does not ask whether Plant Sterols is a good idea for someone in your situation. Here is what our Plant Sterols record says about it on its own.

Plant Sterols: dosing

There is no single official dose for everyone, but cholesterol-lowering benefits are generally seen only when enough is taken consistently each day, usually spread across meals. Taking them with food is often recommended, since they work by affecting how cholesterol is absorbed during digestion.The best approach is to follow the directions on your specific product label, since fortified foods and supplements vary in strength.

From our Plant Sterols monograph — the full record covers uses, side effects and every documented interaction.

Read the full Plant Sterols 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 & Plant Sterols

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

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Plant Sterols list.

See the full Plant Sterols interactions page
See every supplement checked against Quinidine, ranked by severity
Evidence & sources

Plant Sterols References

The 3 references that drive our Plant Sterols monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Guardamagna, O., Abello, F., Baracco, V., Federici, G., Bertucci, P., Mozzi, A., Mannucci, L., Gnasso, A., and Cortese, C. Primary hyperlipidemias in children: effect of plant sterol supplementation on plasma lipids and markers of cholesterol synthesis a
  2. Haque Hussain SS, Weir J, Roberts N. Severe dermatitis secondary to plant sterol supplements. Clin Exp Dermatol. 2009 Oct;34(7):e276-7. PubMed
  3. Xue P, Wang Y, Chen Y, et al. A Case of Peripheral Precocious Puberty May Be Caused by a Diet Containing Phytosterols in a 20-Month-Old Boy. Horm Res Paediatr 2022;95(5):484-491. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Plant Sterols and Quinidine Together: Common Questions

Is it safe to take Plant Sterols with Quinidine?
We do not list a known interaction between Plant Sterols and Quinidine. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do Plant Sterols and Quinidine have any of the same side effects?
Yes — our sources link each of them separately to 2 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Does Quinidine interact with any supplements?
Yes. Quinidine has documented interactions with 207 supplements in our database — Plant Sterols is not one of them. The Quinidine interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Plant Sterols monograph Uses, safety profile, and every drug interaction in one place Quinidine drug information The full plain-English guide to this medication Quinidine supplement interactions Every supplement checked against Quinidine, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 3 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Quinidine and Plant Sterols?

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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.