Drug & supplement interaction

Tangerine + Disopyramide Phosphate

Disopyramide Phosphate brand names: Norpace CR, Norpace.

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

Tangerine has a minor interaction with Disopyramide Phosphate. In vitro, tangeretin, a constituent of tangerine, induces a 52% increase in the metabolism of midazolam by cytochrome P450 3A4 (CYP3A4).

Read the full interaction report
SeverityMinor
LikelihoodUnlikely
EvidenceB
What do Severity, Likelihood & Evidence mean?
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Interaction report

Tangerine and Disopyramide Phosphate

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

Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Disopyramide Phosphate

Disopyramide Phosphate falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Tangerine interacts with.

In vitro, tangeretin, a constituent of tangerine, induces a 52% increase in the metabolism of midazolam by cytochrome P450 3A4 (CYP3A4). This suggests that tangeretin may stimulate CYP3A4 activity. However, in humans, drinking tangerine juice 200 mL slightly delayed the absorption, but did not affect the metabolism, of midazolam, a CYP3A4 substrate. Theoretically, tangerine juice might increase CYP3A4 activity and decrease levels of drugs metabolized by this enzyme. However, this effect is unlikely.
Some drugs metabolized by CYP3A4 include amitriptyline (Elavil), amiodarone (Cordarone), citalopram (Celexa), felodipine (Plendil), lansoprazole (Prevacid), ondansetron (Zofran), prednisone (Deltasone, Orasone), sertraline (Zoloft), sibutramine (Meridia), and many others.
Severity Minor Likelihood Unlikely Evidence B

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the short version: your body uses an enzyme called CYP3A4 to break down disopyramide (Norpace). A compound in tangerine, called tangeretin, has shown in lab dishes that it might speed up that enzyme a little. If that happened in real life, it could clear disopyramide slightly faster and make it a touch weaker at controlling your heart rhythm. Disopyramide is an antiarrhythmic, so even small swings in its level deserve respect.

Now the reassuring part. When researchers tested actual tangerine juice in people, it didn't meaningfully change drug metabolism. So this concern is mostly theoretical, and normal amounts of tangerine as food are very unlikely to cause a problem. If you eat tangerines often or notice any palpitations or rhythm changes, just mention it to your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Backman, J. T., Maenpaa, J., Belle, D. J., Wrighton, S. A., Kivisto, K. T., and Neuvonen, P. J. Lack of correlation between in vitro and in vivo studies on the effects of tangeretin and tangerine juice on midazolam hydroxylation. Clin Pharmacol Ther 2000; 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

Tangerine Also Interacts With Other Medications

Tangerine has 642 minor known drug interactions in our database — the Disopyramide Phosphate one above is one of them. If you take anything else, check it against the full list below.

Minor 642 No known interaction 2,188 (incl. Disopyramide Phosphate)
Taking anything else?

Check Another of Your Medications Against Tangerine

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

Everything else you take

See Every Supplement That Interacts With Disopyramide Phosphate

This page covers Tangerine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Disopyramide Phosphate page lists 169 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: 10 major · 117 moderate · 42 minor.

From our pharmacist’s overview on the Disopyramide Phosphate page

“Grapefruit is the first thing I would set aside on disopyramide phosphate (Norpace), a medicine that steadies dangerous heart rhythms, because grapefruit juice can push the drug's blood level up. That pattern dominates the page, since 121 of the 169 flagged ingredients act on the same liver enzyme, CYP3A4, raising the drug's level or,…”

Reviewed by 2 · Jul 18, 2026

Open the Disopyramide Phosphate interaction page

One more smart check

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

We hold 705 real supplement products containing Tangerine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Tangerine. Your product may carry other ingredients that interact with Disopyramide Phosphate too, on top of Tangerine — 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 Tangerine and Disopyramide Phosphate 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 Tangerine
Top 25%

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

29 days ago today
Medication Disopyramide Phosphate
Steady interest

#1,881 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 Tangerine

What is Tangerine?

  • Source of vitamin C
  • Digestive support
  • Aromatherapy and relaxation
  • Cough and phlegm (traditional)
  • Skin and flavoring uses

Tangerine is a sweet citrus fruit that is a good source of vitamin C and other nutrients, and is widely enjoyed as food. While the peel and essential oil are used in traditional medicine and aromatherapy, strong human evidence for specific health benefits beyond basic nutrition is limited. Enjoying tangerines as part of a balanced diet is generally safe for most people.

Read the full Tangerine monograph & all interactions
Medication

About Disopyramide

What Is Disopyramide Used For?

Brand names: Norpace CR, Norpace

Disopyramide — available as Disopyramide Phosphate, Norpace, and Norpace CR — is indicated for the treatment of documented ventricular arrhythmias, such as sustained ventricular tachycardia (a fast, dangerous heart rhythm originating in the lower chambers), that a physician judges to be life-threatening.

Because of its potential to worsen heart rhythm problems, it is generally not recommended for lesser arrhythmias, and it should not be used to treat ventricular premature contractions (extra heartbeats) that cause no symptoms. Treatment is typically started in a hospital setting.

See full Disopyramide drug information
Keep checking

Other Drugs & Tangerine

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

0Major
0Moderate
642Minor
2,187No known interaction
642 Minor 2,187 No interaction
Minor

642 interactions

Showing 60 of 642 minor interactions — see all 642 on the Tangerine page.

No interaction 2,187 drugs checked — show the list

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

Showing the 60 most looked-up of 2,187 medications checked with no known interaction — see the full Tangerine list.

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

Can you take Tangerine with Disopyramide Phosphate?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Tangerine and Disopyramide Phosphate interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Disopyramide Phosphate and Tangerine?

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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.