Drug & supplement interaction

Chokeberry + Diltiazem

Diltiazem brand names: Cardizem, Cardizem SR, Diltiaz SR, Cardizem CD, Tiazac, and others.

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

Chokeberry has a moderate interaction with Diltiazem. Theoretically, chokeberry might increase levels of drugs metabolized by CYP3A4.

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

Chokeberry and Diltiazem

Here is the interaction we found between these two, with the evidence behind it.

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Diltiazem

Diltiazem falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Chokeberry interacts with.

Theoretically, chokeberry might increase levels of drugs metabolized by CYP3A4.
In vitro research shows that chokeberry inhibits CYP3A4. In humans, there is one case report of a drug interaction with trabectedin, a CYP3A4 substrate, which is hypothesized to have been caused by chokeberry inhibition of CYP3A4.
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 short version: your body relies on a liver enzyme called CYP3A4 to clear diltiazem out of your system. Lab studies suggest chokeberry may slow that enzyme down a bit. If it does, diltiazem could linger and build up, which in theory means a stronger blood-pressure-lowering effect and a higher chance of side effects like dizziness, lightheadedness, an unusually slow heartbeat, flushing, or swelling in the ankles.

Now, the reassuring part: this is mostly theoretical. It comes from test-tube work plus a single case report involving a different drug, not from solid human studies with diltiazem. Eating chokeberry in normal food amounts is unlikely to matter much. Concentrated supplements are the bigger question mark, so check with your pharmacist or doctor before starting them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Bräunlich M, Christensen H, Johannesen S, Slimestad R, Wangensteen H, Malterud KE, Barsett H. In vitro inhibition of cytochrome P450 3A4 by Aronia melanocarpa constituents. Planta Med. 2013 Jan;79(2):137-41. PubMed
  2. Strippoli S, Lorusso V, Albano A, Guida M. Herbal-drug interaction induced rhabdomyolysis in a liposarcoma patient receiving trabectedin. BMC Complement Altern Med. 2013 Jul 30;13:199. 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

Chokeberry Also Interacts With Other Medications

Chokeberry has 810 moderate known drug interactions in our database — the Diltiazem one above is one of them. If you take anything else, check it against the full list below.

Moderate 810 No known interaction 2,020 (incl. Diltiazem)
Taking anything else?

Check Another of Your Medications Against Chokeberry

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

From our Q&A

Questions About Chokeberry or Diltiazem

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

This page covers Chokeberry only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Diltiazem page lists 260 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Coleus (major) and Grapefruit (major).

By severity: 7 major · 214 moderate · 39 minor.

From our pharmacist’s overview on the Diltiazem page

“Someone on diltiazem (Cardizem, Tiazac) is usually managing blood pressure, angina, or a fast heart rhythm, so this list deserves genuine care. Seven of the 260 ingredients on file carry a major rating, and two of those are things people actually buy: grapefruit, which blocks the enzyme that clears diltiazem and can push its blood leve…”

Reviewed by 2 · Jul 18, 2026

Open the Diltiazem interaction page

One more smart check

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

We hold 493 real supplement products containing Chokeberry, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Chokeberry. Your product may carry other ingredients that interact with Diltiazem too, on top of Chokeberry — 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 Chokeberry and Diltiazem 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 Chokeberry
Top half

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

29 days ago today
Medication Diltiazem
Top 10%

#284 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 Chokeberry

What is Chokeberry?

Chokeberry
  • Antioxidant support
  • Heart and blood vessel health
  • Blood pressure support
  • Blood sugar support
  • Common cold symptoms
  • Anti-inflammatory support

Chokeberry (aronia) is a dark berry rich in antioxidants called polyphenols, and it's widely eaten as juice, jam, and supplements. Early research hints it may support heart health, blood pressure, and blood sugar, but the evidence is still limited and far from proven. It's generally well tolerated as a food, but talk to your pharmacist or doctor before using concentrated supplements.

Read the full Chokeberry monograph & all interactions
Medication

About Diltiazem

What Is Diltiazem Used For?

Brand names: Cardizem, Cardizem SR, Diltiaz SR, Cardizem CD, Tiazac, Diltiaz XT, Diltiaz CD, Dilacor, Diltiaz, Cardizem LA, Dilacor XR, Cartia XT, Tiamate, Adizem-SR, Adizem-XL, Angitil SR, Angitil XL, Calcicard CR, Dilcardia SR, Dilzem SR, Dilzem XL, Slozem, Tildiem LA, Tildiem Retard, Viazem XL, Zemtard 120XL, Zemtard 180XL, Zemtard 240XL, Zemtard 300XL

Oral extended-release diltiazem (capsules and tablets) treats high blood pressure (hypertension). It is also used for chronic stable angina, which is chest pain from the heart working harder than its blood supply allows. It can be used alone or with other blood pressure medicines.

Some extended-release capsule products, such as Cartia, Cartia Xt and certain generic diltiazem capsules, are also approved for angina due to coronary artery spasm. The intravenous (IV) injection is a different use: it gives temporary control of a rapid heart rate in atrial fibrillation or atrial flutter, and rapidly converts paroxysmal supraventricular tachycardia (PSVT) to normal rhythm.

See full Diltiazem drug information
Keep checking

Other Drugs & Chokeberry

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

0Major
810Moderate
0Minor
2,019No known interaction
810 Moderate 2,019 No interaction
Moderate

810 interactions

Showing 60 of 810 moderate interactions — see all 810 on the Chokeberry page.

No interaction 2,019 drugs checked — show the list

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

Showing the 60 most looked-up of 2,019 medications checked with no known interaction — see the full Chokeberry list.

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

Can you take Chokeberry with Diltiazem?
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.
How serious is the Chokeberry and Diltiazem 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 Diltiazem and Chokeberry?

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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.