Drug & supplement interaction

Cinchona + Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide

Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide brand name: Ascriptin Codeine #3.

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

Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide falls into 3 drug categories that Cinchona can interact with; the most serious is rated moderate. Theoretically, taking cinchona might inhibit cytochrome P450 2D6 (CYP2D6) and increase levels of drugs metabolized by this enzyme.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Cinchona and Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Cinchona interacts with whole categories of medication. Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide falls into 3 of those categories, so it can interact with Cinchona in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

1 of 3

Why this applies to Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide

Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES — the group Cinchona interacts with.

Theoretically, taking cinchona might inhibit cytochrome P450 2D6 (CYP2D6) and increase levels of drugs metabolized by this enzyme.
Quinidine, a constituent of cinchona, inhibits CYP2D6-mediated metabolism in humans.
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 wrinkle with this combo product: the part that matters is the codeine. Codeine is a prodrug, meaning it doesn't do much until your body converts it into morphine using a liver enzyme called CYP2D6. Cinchona bark contains quinidine, which is a well-known blocker of that very enzyme.

So in theory, taking cinchona could slow that conversion and leave you with less pain relief from the codeine, not more. The aspirin and the antacids (aluminum and magnesium hydroxide) aren't really affected here. Keep in mind this is a theoretical concern based on how the chemistry works, not strong human studies. Still, cinchona supplements carry their own heart and blood risks, so please check with your pharmacist or doctor before mixing them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  2. 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
Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

2 of 3

Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide also falls under ANTICOAGULANT/ANTIPLATELET DRUGS.

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

This combination product already contains aspirin, which thins your blood by keeping platelets from clumping together. Cinchona bark holds quinine-like compounds that, in lab tests, also slow down platelets. So the worry here is simple: stacking the two could add up and push your blood toward thinning more than expected.

What that might look like in real life is easier bruising, nosebleeds, bleeding gums, or a cut that takes longer to stop. Keep in mind this is a theoretical concern based on lab studies, not strong human proof, so don't panic. Still, since aspirin and cinchona can both nudge bleeding in the same direction, I'd check with your pharmacist or doctor before pairing them.

Contact Dr. Brian directly if you have additional questions on this interaction
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
Moderate

ANTACIDS

3 of 3

Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide also falls under ANTACIDS.

Theoretically, taking cinchona might decrease the effectiveness of antacids. Theoretically, taking antacids might also increase the risk of adverse effects from cinchona.
Some research shows that taking cinchona lowers stomach acid pH. In addition, some research shows that taking antacids might increase urinary pH. Theoretically, this may increase the amount of quinidine, a constituent of cinchona, reabsorbed in the renal tubules and increase the risk of quinidine toxicity.
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

This combo product contains two antacids, aluminum hydroxide and magnesium hydroxide. Cinchona bark can theoretically work against those antacids in two ways. First, cinchona may lower your stomach pH a bit, which could blunt the soothing, acid-neutralizing relief you take the antacids for. Second, and more importantly, antacids can make your urine less acidic, and that may cause your kidneys to hold onto more of the quinidine and quinine in cinchona bark.

That second part matters most. Building up quinidine can stress the heart and cause problems like irregular heartbeats, ringing in the ears, dizziness, or nausea. Keep in mind this is theoretical, based on how these chemicals behave, not on strong studies. Honestly, cinchona bark itself is unpredictable. Please check with your pharmacist before mixing the two.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  2. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.

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 Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide one above is among them. If you take anything else, check it against the full list below.

Major 3 Moderate 472 Minor 16 No known interaction 2,339 (incl. Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide)
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 Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide

This page covers Cinchona only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide page lists 293 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Asarabacca (major), Beer (major) and Danshen (major).

By severity: 8 major · 246 moderate · 39 minor.

From our pharmacist’s overview on the Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide page

“Bleeding dominates the supplement list for Ascriptin Codeine #3, which pairs aspirin and codeine with two antacid ingredients. Of 293 interactions on file, 8 are rated major, and this combination pill earns real caution.”

Reviewed by 2 · Jul 18, 2026

Open the Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide 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 Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide 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 Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide 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

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

29 days ago today
Medication Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide
Top 10%

#160 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
3 Major 472 Moderate 16 Minor 2,338 No 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

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 2,338 medications checked with no known interaction — see the full Cinchona list.

See the full Cinchona interactions page
See every supplement checked against Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide, 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
Cinchona monograph › Uses, safety, and every drug interaction in one place Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide supplement interactions › Every supplement checked against Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide, 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 Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Cinchona and Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide Together: Common Questions

Can you take Cinchona with Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide?
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 3 interactions listed for Cinchona and Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide?
Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide belongs to more than one drug category, and Cinchona 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 Cinchona and Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide 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.