Drug & supplement interaction

Breadfruit + Penbutolol Sulfate

Penbutolol Sulfate brand name: Levatol.

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

Breadfruit has a moderate interaction with Penbutolol Sulfate. Theoretically, concomitant use with antihypertensive drugs might increase the risk of hypotension.

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

Breadfruit and Penbutolol Sulfate

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

Moderate

ANTIHYPERTENSIVE DRUGS

Why this applies to Penbutolol Sulfate

Penbutolol Sulfate falls under ANTIHYPERTENSIVE DRUGS — the group Breadfruit interacts with.

Theoretically, concomitant use with antihypertensive drugs might increase the risk of hypotension. Animal research shows that breadfruit leaf extract can decrease heart rate and weaken the force of heart muscle contractions, which may lower blood pressure.
Some antihypertensive drugs include captopril (Capoten), enalapril (Vasotec), losartan (Cozaar), valsartan (Diovan), diltiazem (Cardizem), amlodipine (Norvasc), hydrochlorothiazide (HydroDIURIL), furosemide (Lasix), and many others.
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 gist: penbutolol (Levatol) is a beta blocker that already lowers your blood pressure and slows your heart rate. The concern with concentrated breadfruit leaf products (think teas or extracts, not the fruit on your dinner plate) is that they may push in the same direction. In animal studies, breadfruit leaf extract slowed the heart and weakened how hard the heart muscle squeezed, which can drop blood pressure further.

Stacked on top of penbutolol, that could mean too much of a good thing: dizziness, lightheadedness when you stand, fatigue, or a heart rate that runs too slow. I want to be honest though, this is theoretical and based on lab and animal work, not human studies. Eating breadfruit as food is generally fine. If you're considering leaf supplements, run it by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Young RE, Williams LAD, Gardner MT, Fletcher CK. An extract of the leaves of the breadfruit Artocarpus altilis (parkinson) fosberg exerts a negative inotropic effect on rat myocardium. Phytother Res 2006;7(2):190-193.

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

Breadfruit Also Interacts With Other Medications

Breadfruit has 437 moderate, 504 minor known drug interactions in our database — the Penbutolol Sulfate one above is one of them. If you take anything else, check it against the full list below.

Moderate 437 Minor 504 No known interaction 1,889 (incl. Penbutolol Sulfate)
Taking anything else?

Check Another of Your Medications Against Breadfruit

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

Everything else you take

See Every Supplement That Interacts With Penbutolol Sulfate

This page covers Breadfruit only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Penbutolol Sulfate page lists 139 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), Indian Snakeroot (major) and Tyramine (major).

By severity: 5 major · 113 moderate · 21 minor.

From our pharmacist’s overview on the Penbutolol Sulfate page

“Penbutolol sulfate (Levatol) is a beta-blocker that lowers blood pressure and slows the heart, and its supplement file earns real vigilance, since five of the 139 ingredients on record carry a major rating. The great majority, 119 ingredients, tug on blood pressure one way or the other, some stacking with the drug until it falls too fa…”

Reviewed by 2 · Jul 18, 2026

Open the Penbutolol Sulfate interaction page

How much people look this up

Where Breadfruit and Penbutolol Sulfate 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 Breadfruit
Steady interest

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

29 days ago today
Medication Penbutolol Sulfate
Top half

#1,396 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 Breadfruit

What is Breadfruit?

  • Source of nutrition and energy
  • High blood pressure
  • Diabetes and blood sugar support
  • Inflammation and joint discomfort
  • Skin conditions

Breadfruit is a starchy tropical fruit eaten as a staple food, and its leaves are used in traditional medicine for conditions like high blood pressure and diabetes. As a food it is nutritious and generally safe, but the medicinal use of leaf teas or extracts has very little human research to back it up. Talk with your pharmacist or doctor before using breadfruit products for a health condition.

Read the full Breadfruit monograph & all interactions
Medication

About Penbutolol

What Is Penbutolol Used For?

Brand name: Levatol

  • Penbutolol is used to treat high blood pressure. Penbutolol is in a class of medications called beta blockers. It works by relaxing blood vessels and slowing heart rate to improve blood flow and decrease blood pressure.

See full Penbutolol drug information
Keep checking

Other Drugs & Breadfruit

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

0Major
437Moderate
504Minor
1,888No known interaction
437 Moderate 504 Minor 1,888 No interaction
Moderate

437 interactions

Showing 60 of 437 moderate interactions — see all 437 on the Breadfruit page.

Minor

504 interactions

Showing 60 of 504 minor interactions — see all 504 on the Breadfruit page.

No interaction 1,888 drugs checked — show the list

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

Showing the 60 most looked-up of 1,888 medications checked with no known interaction — see the full Breadfruit list.

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

Can you take Breadfruit with Penbutolol Sulfate?
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 Breadfruit and Penbutolol Sulfate 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 Penbutolol Sulfate and Breadfruit?

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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.