Drug & supplement interaction

Quebracho Blanco + Hydroxychloroquine

Hydroxychloroquine brand name: Plaquenil.

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 Quebracho Blanco and Hydroxychloroquine 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 label for Hydroxychloroquine states a food rule worth keeping to, and 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

Quebracho Blanco and Hydroxychloroquine

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 Hydroxychloroquine and Quebracho Blanco 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 Quebracho Blanco at all — not against Hydroxychloroquine, 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.

Quebracho Blanco safety at a glance

Quebracho Blanco overall Use caution Limited human safety data and the bark contains active alkaloids, so use cautiously.
Pregnancy Avoid Not enough safety information; avoid use during pregnancy.
Breastfeeding Avoid No reliable safety data, so avoid while breastfeeding.

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

Still wondering about combining Hydroxychloroquine and Quebracho Blanco? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Quebracho Blanco and Hydroxychloroquine 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.

  • Dizziness / Headache Additional detail

    Quebracho Blanco

    “Orally, quebracho blanco seems to be well tolerated. However, a thorough evaluation of safety outcomes has not been conducted. Some people who take quebracho blanco bark may experience salivation, headache, outbreaks of sweating, vertigo, stupor, and drowsiness. In large doses, it can cause nausea and vomiting (18).”

    Quebracho Blanco · Natural Medicines adverse-effect record, reported in cluster headache.

    1 source cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

    “Orally, quebracho blanco bark may cause headache, vertigo, stupor, and drowsiness (18).”

    Quebracho Blanco · Natural Medicines adverse-effect record, reported in cluster headache.

    1 source cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

    Hydroxychloroquine

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

  • Vomiting / Nausea Additional detail

    Quebracho Blanco

    “Orally, quebracho blanco bark may cause salivation. In large doses, it can cause nausea and vomiting (18).”

    Quebracho Blanco · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    1 source cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

    Hydroxychloroquine

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

Reported for Quebracho Blanco but not commonly for Hydroxychloroquine: drowsiness and sweating.

Effects for Hydroxychloroquine come from the ADVERSE REACTIONS section of its FDA label; effects for Quebracho Blanco 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.

How to take them

Some Hydroxychloroquine Products Have a Food Rule — Quebracho Blanco Should Not Break It

At least one FDA label for a product containing Hydroxychloroquine says to take it with food. If you take Quebracho Blanco on an empty stomach out of habit, keep them separate — and take Hydroxychloroquine with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Hydroxychloroquine products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

Rheumatoid Arthritis in Adults ( 2.3 ): Initial dosage: 400 mg to 600 mg daily Chronic dosage: 200 mg once daily or 400 mg once daily (or in two divided doses) Systemic Lupus Erythematosus in Adults ( 2.4 ): 200 mg once daily or 400 mg once daily (or in two divided doses) Chronic Discoid Lupus Erythematosus in Adults ( 2.5 ): 200 mg once daily or 400 mg once daily (or in two divided doses) 2.1 Imp

From the Dosage and Administration section of the FDA label we read for Hydroxychloroquine — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

From our Q&A

Questions About Quebracho Blanco or Hydroxychloroquine

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

This page covers Quebracho Blanco only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Hydroxychloroquine page lists 32 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), Cesium (major) and Ephedra (major).

By severity: 7 major · 16 moderate · 9 minor.

From our pharmacist’s overview on the Hydroxychloroquine page

“Hydroxychloroquine (Plaquenil) can stretch the QT interval on its own, the pause between heartbeats that, prolonged too far, can trigger a dangerous rhythm. Thirteen of the supplements and herbs on this page add to that same effect, grapefruit in large amounts among them, and that overlap is why this list calls for genuine care rather…”

Reviewed by 2 · Jul 18, 2026

Open the Hydroxychloroquine interaction page

How much people look this up

Where Quebracho Blanco and Hydroxychloroquine 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 Quebracho Blanco
Steady interest

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

29 days ago today
Medication Hydroxychloroquine
Top 25%

#301 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 Quebracho Blanco reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Quebracho Blanco and Hydroxychloroquine 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 Quebracho Blanco

What is Quebracho Blanco?

  • Coughs and breathing problems
  • Asthma and bronchitis symptoms
  • Altitude or shortness of breath
  • Erectile dysfunction (traditional)
  • Fever and digestive upset

Quebracho Blanco is the bark of a South American tree traditionally used for breathing problems and coughs, but high-quality human studies are lacking. It contains alkaloids that may affect blood vessels and breathing, so safety is not well established—talk to your pharmacist or doctor before using it.

Aspidosperma quebracho-blanco · Apocynaceae · Bark · Tincture, liquid extract, dried bark for tea, capsules

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

Quebracho Blanco: dosing

There is no well-established or standardized dose for quebracho blanco. The amount of active alkaloids can vary a lot between products, which makes safe dosing hard to determine.If you choose to use a quebracho product, follow the directions on the label and do not exceed the recommended amount.

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

Read the full Quebracho Blanco monograph & all interactions
Medication

About Hydroxychloroquine

What Is Hydroxychloroquine Used For?

Brand name: Plaquenil

Hydroxychloroquine tablets are used to treat uncomplicated malaria and to help prevent malaria in areas where the parasite has not developed resistance to it — in both adults and children. It is also used in adults to treat rheumatoid arthritis, systemic lupus erythematosus (SLE), and chronic discoid lupus erythematosus.

There are important limits: it is not recommended for complicated or drug-resistant malaria, malaria acquired in regions where resistance is known, or to prevent malaria relapses caused by P. vivax or P. ovale. Its use for the autoimmune conditions (rheumatoid arthritis and lupus) is approved for adults only.

See full Hydroxychloroquine drug information
Keep checking

Other Drugs & Quebracho Blanco

Browse every other medication we’ve checked against Quebracho Blanco — 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 Quebracho Blanco 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 Quebracho Blanco list.

See the full Quebracho Blanco interactions page
See every supplement checked against Hydroxychloroquine, ranked by severity
Evidence & sources

Quebracho Blanco References

The 1 references that drive our Quebracho Blanco 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. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

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 Quebracho Blanco and Hydroxychloroquine Together: Common Questions

Is it safe to take Quebracho Blanco with Hydroxychloroquine?
We do not list a known interaction between Quebracho Blanco and Hydroxychloroquine. 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 Quebracho Blanco and Hydroxychloroquine have any of the same side effects?
Yes — our sources link each of them separately to 4 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.
Should I take Quebracho Blanco and Hydroxychloroquine at the same time of day?
At least one FDA label for a product containing Hydroxychloroquine says to take it with food. If you take Quebracho Blanco on an empty stomach out of habit, keep them separate and take Hydroxychloroquine with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Hydroxychloroquine products can differ — so check the directions on your own box. This is about absorption, not an interaction.
Does Hydroxychloroquine interact with any supplements?
Yes. Hydroxychloroquine has documented interactions with 32 supplements in our database — Quebracho Blanco is not one of them. The Hydroxychloroquine 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

Quebracho Blanco monograph Uses, safety profile, and every drug interaction in one place Hydroxychloroquine drug information The full plain-English guide to this medication Hydroxychloroquine supplement interactions Every supplement checked against Hydroxychloroquine, 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 1 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Hydroxychloroquine and Quebracho Blanco?

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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.