Drug & supplement interaction

Feingold Diet + Flecainide

Flecainide brand name: Tambocor.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Feingold Diet and Flecainide 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

Feingold Diet and Flecainide

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 Flecainide and Feingold Diet in our sources. This does not guarantee that the combination is completely free of risk — research on Feingold Diet alongside specific medications may be limited.

Worth understanding: our licensed dataset holds no drug-interaction record for Feingold Diet at all — not against Flecainide, 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.

Feingold Diet is an eating pattern rather than something you take. Ask your pharmacist or doctor before changing how you eat while on a prescribed medicine: some medicines are dosed around meals, and a change in diet can change how they work. 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.

Feingold Diet safety at a glance

Feingold Diet overall Use caution Generally low risk, but restrictive diets in children can lead to nutrition gaps if not supervised.
Pregnancy Use caution The diet is aimed at children; pregnant people should not follow restrictive diets without medical guidance.
Breastfeeding Use caution Restricting your own diet while breastfeeding is not recommended without a clinician's advice.

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

Still wondering about combining Flecainide and Feingold Diet? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Flecainide’s Own FDA Label Lists

This is not an interaction — none of it involves Feingold Diet. These are the most notable effects listed in the ADVERSE REACTIONS section of Flecainide’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you follow Feingold Diet and take the medicine. 10 of them are worth acting on rather than waiting out — marked below.

  • Memory problems Worth acting on
  • Trouble passing urine Worth acting on
  • Unsteadiness Worth acting on
  • A slow heartbeat Worth acting on
  • A heart attack Worth acting on
  • Yellowing of the skin or eyes Worth acting on
  • Fainting Worth acting on
  • Wheezing Worth acting on
  • An irregular heartbeat Worth acting on
  • Confusion Worth acting on

Showing the 10 most notable of 53 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Flecainide. Read the label on DailyMed › Feingold Diet’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Feingold Diet side to compare — that is a limit of the record, not a statement that Feingold Diet has no side effects.

From our Q&A

Questions About Feingold Diet or Flecainide

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

This page covers Feingold Diet only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Flecainide page lists 86 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 · 61 moderate · 18 minor.

From our pharmacist’s overview on the Flecainide page

“Flecainide (Tambocor) exists to control serious heart rhythm problems, so anything that disturbs the rhythm it protects deserves genuine caution. Six of the seven major-rated entries among the 86 supplements and herbs on file, grapefruit in large amounts included, can prolong the QT interval, the heart's electrical reset time, adding t…”

Reviewed by 2 · Jul 18, 2026

Open the Flecainide interaction page

How much people look this up

Where Feingold Diet and Flecainide 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 Feingold Diet
Steady interest

#1,117 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Flecainide
Top 25%

#483 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 Feingold Diet reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Feingold Diet and Flecainide 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 .
Eating pattern

About Feingold Diet

What is Feingold Diet?

  • Hyperactivity (ADHD) in children
  • Behavioral problems in kids
  • Attention and focus concerns
  • Childhood sleep and mood issues

The Feingold Diet is an elimination eating plan that removes certain artificial food colors, flavors, sweeteners, preservatives, and some natural salicylate-containing foods, mainly to reduce hyperactivity in children. Scientific evidence is mixed and limited, though a small number of children may be sensitive to specific food additives. If you try it, work with a pediatrician or registered dietitian so your child still gets balanced nutrition.

Elimination diet / structured eating plan

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

Feingold Diet: dosing

There is no pill or standardized "dose" for the Feingold Diet — it is a pattern of eating. It is typically done in phases: a stricter starting period that removes targeted additives and salicylate-rich foods, followed by gradual reintroduction to identify specific triggers.Because the diet can be complex and restrictive, it is best to follow program guidance and work with a registered dietitian or pediatrician to make sure your child's overall diet stays balanced.

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

Read the full Feingold Diet monograph & all interactions
Medication

About Flecainide

What Is Flecainide Used For?

Brand name: Tambocor

Flecainide Acetate tablets are used to prevent episodes of certain abnormal heart rhythms. In patients without structural heart disease, it is approved to prevent paroxysmal supraventricular tachycardia (PSVT — episodes of rapid heart rate starting above the ventricles) and paroxysmal atrial fibrillation/flutter (PAF — intermittent episodes of irregular, rapid heart rhythm in the upper chambers), when these cause disabling symptoms.

Flecainide Acetate tablets are also used to prevent life-threatening ventricular arrhythmias — dangerous rapid rhythms starting in the lower chambers of the heart, such as sustained ventricular tachycardia. It is not recommended for less serious ventricular arrhythmias, for patients with a recent heart attack, or for chronic (ongoing, persistent) atrial fibrillation.

See full Flecainide drug information
Keep checking

Other Drugs & Feingold Diet

Browse every other medication we’ve checked against Feingold Diet — 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
No interaction 2,829 drugs checked — show the list
Evidence & sources

Feingold Diet References

The 2 references that drive our Feingold Diet 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. Conners CK, Goyette CH, Southwick DA, et al. Food additives and hyperkinesis: a controlled double-blind experiment. Pediatrics 1976;58:154-66. DOI
  2. Harley JP, Ray RS, Tomasi L, et al. Hyperkinesis and food additives: testing the Feingold hypothesis. Pediatrics 1978;61:818-28. DOI

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

Following Feingold Diet While Taking Flecainide: Common Questions

Is it safe to follow Feingold Diet while taking Flecainide?
We do not list a known interaction between Feingold Diet and Flecainide. 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.
Does Flecainide interact with any supplements?
Yes. Flecainide has documented interactions with 86 supplements in our database — Feingold Diet is not one of them. The Flecainide interaction page linked on this page lists every one, ranked by severity.

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

Still Have a Question About Flecainide and Feingold Diet?

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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.