Drug & supplement interaction

Cinchona + Estramustine Phosphate Sodium

Estramustine Phosphate Sodium brand name: Emcyt.

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 Cinchona and Estramustine Phosphate Sodium 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.

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Interaction report

Cinchona and Estramustine Phosphate Sodium

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 Estramustine Phosphate Sodium and Cinchona 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.

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.

Cinchona safety at a glance

Cinchona overall Use caution Contains quinine, which can cause serious side effects, and the bark is not dose-controlled.
Pregnancy Likely Unsafe When used orally. Cinchona is reported to have uterine stimulant and abortifacient activity, and to be fetotoxic and teratogenic, causing visual and auditory de... Read the full pregnancy detail
Breastfeeding Possibly Unsafe When used orally. The cinchona alkaloids quinine and quinidine are reported to be excreted in breast milk and may be toxic to infants. Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Estramustine Phosphate Sodium and Cinchona? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Estramustine Phosphate Sodium

Interactions in our licensed database are recorded against drug classes, not just single drug names. Estramustine Phosphate Sodium is filed under 2 classifications — alkylating agents, oral drugs. Cinchona has documented interactions with 11 drug classes — the most serious being quinidine (major), quinine (major) and antacids (moderate) — and none of Estramustine Phosphate Sodium’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Cinchona Does Interact With Other Medications

Cinchona has 3 major, 473 moderate, 16 minor known drug interactions in our database — Estramustine Phosphate Sodium isn’t one of them. If you take anything else, check it against the full list below.

Major 3 Moderate 473 Minor 16 No known interaction 2,338 (incl. Estramustine Phosphate Sodium)
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.

What to actually watch for

What Cinchona Itself Has Been Linked To

This is not an interaction — nothing below involves Estramustine Phosphate Sodium. It is the side-effect record for Cinchona on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Cinchona, this list is the first place to look. 6 entries are worth acting on rather than waiting out — marked below.

  • Loss of vision / Hearing loss Worth acting on Additional detail

    “Orally, prolonged use of high doses of cinchona or its alkaloids, or a single dose of 3 grams or more of the alkaloid quinine are associated with a toxicity syndrome known as cinchonism. Symptoms include headache, dizziness, nausea and vomiting, diarrhea, hemolysis, hypotension, cardiac arrhythmias, tinnitus, deafness, vision changes, blindness, abdominal pain, delirium, convulsions, paralysis, and collapse (6,12,19,…”

    Cinchona · Natural Medicines adverse-effect record, reported in arrhythmia.

    6 sources cited
    1. 6. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
    2. 12. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
    3. 19. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
    4. 505. Hardman JG, Limbird LL, Molinoff PB, eds. Goodman and Gillman's The Pharmacological Basis of Therapeutics, 9th ed. New York, NY: McGraw-Hill, 1996.
    5. 93232. US Food and Drug Administration notice: Drug products containing quinine - enforcement action dates. Docket # 2006N-0476. Federal Register 2006 (December 15);71 (241): 75557-60.
    6. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

    “Cinchona contains quinine that can cause dose-related adverse effects on hearing and vision, including tinnitus, deafness, vision changes, and blindness (6,8,12,93232).”

    Cinchona · Natural Medicines adverse-effect record, reported in tinnitus.

    4 sources cited
    1. 6. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
    2. 8. Wichtl MW. Herbal Drugs and Phytopharmaceuticals. Ed. N.M. Bisset. Stuttgart: Medpharm GmbH Scientific Publishers, 1994.
    3. 12. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
    4. 93232. US Food and Drug Administration notice: Drug products containing quinine - enforcement action dates. Docket # 2006N-0476. Federal Register 2006 (December 15);71 (241): 75557-60.
  • An irregular heartbeat Worth acting on Additional detail

    “Cinchona contains the alkaloids quinidine and quinine that can prolong the QT interval on the electrocardiogram, and cause potentially fatal cardiac arrhythmias such as torsades de pointes”

    Cinchona · Natural Medicines adverse-effect record, reported in arrhythmia.

    2 sources cited
    1. 3046. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
    2. 93232. US Food and Drug Administration notice: Drug products containing quinine - enforcement action dates. Docket # 2006N-0476. Federal Register 2006 (December 15);71 (241): 75557-60.
  • Confusion / Seizures Worth acting on Additional detail

    Recorded for Cinchona in the same Natural Medicines adverse-effect record shown under Loss of vision / Hearing loss above.

  • A low platelet count / Kidney problems / Anemia Worth acting on Additional detail

    “Quinine, which is present in cinchona, has been associated with serious, sometimes fatal, hematological disorders including thrombocytopenia, thrombotic thrombocytopenic purpura (TTP), and hemolytic uremic syndrome (hemolytic anemia, acute renal failure, and thrombocytopenia). Initial symptoms may include bleeding from the gums, nose or gastrointestinal tract, easy bruising, and petechiae.”

    Cinchona · Natural Medicines adverse-effect record, reported in anemia.

    3 sources cited
    1. 93232. US Food and Drug Administration notice: Drug products containing quinine - enforcement action dates. Docket # 2006N-0476. Federal Register 2006 (December 15);71 (241): 75557-60.
    2. 93233. FDA Drug Safety Communication: New risk management plan and patient medication guide for Qualaquin (quinine sulfate). 07-08-2010. https://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm218202 (accessed 02/18/17).
    3. 505. Hardman JG, Limbird LL, Molinoff PB, eds. Goodman and Gillman's The Pharmacological Basis of Therapeutics, 9th ed. New York, NY: McGraw-Hill, 1996.
  • Hives Worth acting on Additional detail

    Recorded for Cinchona in the same Natural Medicines adverse-effect record shown under An irregular heartbeat above.

  • Bleeding or bruising Worth acting on Additional detail

    Recorded for Cinchona in the same Natural Medicines adverse-effect record shown under An irregular heartbeat above.

Showing the 10 most notable of 22 recorded effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

Everything above comes from the Natural Medicines adverse-effect record for Cinchona — expand a row for the licensed statement it rests on. We haven’t matched Estramustine Phosphate Sodium to its FDA label in our system yet, so we can’t compare its own side-effect list here — the leaflet that comes with your prescription is the authoritative list for Estramustine Phosphate Sodium.

Special populations

Cinchona in Pregnancy & Breastfeeding

Pregnancy Likely Unsafe

When used orally. Cinchona is reported to have uterine stimulant and abortifacient activity, and to be fetotoxic and teratogenic, causing visual and auditory defects. Avoid using.

Lactation Possibly Unsafe

When used orally. The cinchona alkaloids quinine and quinidine are reported to be excreted in breast milk and may be toxic to infants.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

Overlapping uses

What Estramustine Phosphate Sodium Is Prescribed For, and What Cinchona Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Estramustine Phosphate Sodium is a prescription medicine with approved uses on its FDA label. Cinchona is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Cinchona has been studied for:

  • Cancer studied, not established Cinchona has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Cinchona for cancer

    Although there has been interest in using oral cinchona for cancer, there is insufficient reliable information about the clinical effects of cinchona for this purpose.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Estramustine Phosphate Sodium on your own; if you are taking Cinchona for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

Everything else you take

See Every Supplement That Interacts With Estramustine Phosphate Sodium

This page covers Cinchona only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Estramustine Phosphate Sodium page lists 24 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Acerola (moderate), Alpha-lipoic Acid (moderate), Coenzyme Q10 (moderate) and Coffee Charcoal (moderate).

By severity: 1 major · 14 moderate · 9 minor.

From our pharmacist’s overview on the Estramustine Phosphate Sodium page

“Estramustine phosphate sodium (Emcyt) is an oral chemotherapy for advanced prostate cancer, so supplements that weaken it carry real weight, and this list of 24 ingredients warrants genuine care. Nearly everything here does one of two things: fiber-heavy products like psyllium and various gums can keep the capsule from being absorbed p…”

Reviewed by 2 · Jul 18, 2026

Open the Estramustine Phosphate Sodium 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. Even though Cinchona itself has no known interaction with Estramustine Phosphate Sodium, 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 Cinchona and Estramustine Phosphate Sodium 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

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

29 days ago today
Medication Estramustine Phosphate Sodium
Top half

#1,174 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 Cinchona reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Cinchona and Estramustine Phosphate Sodium records this page draws on were last updated July 11, 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 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.

Cinchona officinalis · Rubiaceae · Bark · Dried bark, tinctures, liquid extracts, capsules, teas, and as a bitter flavoring in tonic water

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

Cinchona: dosing

There is no well-established safe dose for cinchona bark as a supplement. The amount of quinine and other alkaloids can vary a lot from product to product, which makes safe dosing difficult.If you are considering a cinchona product, follow the directions on the label and do not exceed them.

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

Read the full Cinchona monograph & all interactions
Medication

About Estramustine

What Is Estramustine Used For?

Brand name: Emcyt

  • Estramustine is used to treat prostate cancer that has worsened or has spread to other parts of the body. Estramustine is in a class of medications called antimicrotubule agents. It works by stopping the growth and spread of cancer cells.

See full Estramustine 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
473Moderate
16Minor
2,337No known interaction
3 Major 473 Moderate 16 Minor 2,337 No interaction
Major

3 interactions

Moderate

473 interactions

Showing 60 of 473 moderate interactions — see all 473 on the Cinchona page.

Minor

16 interactions

No interaction 2,337 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 2,337 medications checked with no known interaction — see the full Cinchona list.

See the full Cinchona interactions page
See every supplement checked against Estramustine Phosphate Sodium, ranked by severity
Evidence & sources

Cinchona References

The 15 references that drive our Cinchona 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. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  2. Wichtl MW. Herbal Drugs and Phytopharmaceuticals. Ed. N.M. Bisset. Stuttgart: Medpharm GmbH Scientific Publishers, 1994.
  3. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  4. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  5. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  6. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  7. Holt GA. Food & Possible Interactions with Drugs: Revised and Expanded Ed. Chicago, IL: Precept Press, 1998.
  8. Hardman JG, Limbird LL, Molinoff PB, eds. Goodman and Gillman's The Pharmacological Basis of Therapeutics, 9th ed. New York, NY: McGraw-Hill, 1996.
  9. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  10. Amabeoku GJ, Chikuni O, Akino C, Mutetwa S. Pharmacokinetic interaction of single doses of quinine and carbamazepine, phenobarbitone and phenytoin in healthy volunteers. East Afr Med J 1993;70:90-3.
  11. 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
  12. US Food and Drug Administration notice: Drug products containing quinine - enforcement action dates. Docket # 2006N-0476. Federal Register 2006 (December 15);71 (241): 75557-60.
  13. FDA Drug Safety Communication: New risk management plan and patient medication guide for Qualaquin (quinine sulfate). 07-08-2010. https://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm218202 (accessed 02/18/17).
  14. Dooms-Goossens A, Deveylder H, Duron C, et al. Airborne contact urticaria due to cinchona. Contact Dermatitis 1986;15(4):258. PubMed
  15. Bramer SL, Suri A. Inhibition of CYP2D6 by quinidine and its effects on the metabolism of cilostazol. Clin Pharmacokinet. 1999;37 Suppl 2:41-51. 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 Cinchona and Estramustine Phosphate Sodium Together: Common Questions

Is it safe to take Cinchona with Estramustine Phosphate Sodium?
We do not list a known interaction between Cinchona and Estramustine Phosphate Sodium. 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.
Are Cinchona and Estramustine Phosphate Sodium used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Cinchona in each. That is a conversation for your prescriber, especially if Estramustine Phosphate Sodium is being adjusted to a target.
How was the Cinchona and Estramustine Phosphate Sodium combination checked?
Interactions in our licensed database are recorded against drug classes. Estramustine Phosphate Sodium is filed under 2 classifications, and Cinchona has documented interactions with 11 drug classes — none of Estramustine Phosphate Sodium's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Cinchona interact with any other medications?
Yes. Cinchona has 492 documented drug interactions in our database — Estramustine Phosphate Sodium is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Estramustine Phosphate Sodium interact with any supplements?
Yes. Estramustine Phosphate Sodium has documented interactions with 24 supplements in our database — Cinchona is not one of them. The Estramustine Phosphate Sodium 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

Cinchona monograph Uses, safety profile, and every drug interaction in one place Estramustine drug information The full plain-English guide to this medication Estramustine Phosphate Sodium supplement interactions Every supplement checked against Estramustine Phosphate Sodium, 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 15 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Estramustine Phosphate Sodium 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.