Drug & supplement interaction

Oleander + Chlorthalidone

Chlorthalidone brand names: Hygroton, Thalitone.

Major Interaction
Medically reviewed by · Updated October 2026
The bottom line Major

Oleander has a major interaction with Chlorthalidone. Theoretically, diuretic drugs may increase the risk of oleander toxicity.

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

Oleander and Chlorthalidone

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

Major

DIURETIC DRUGS

Why this applies to Chlorthalidone

Chlorthalidone falls under DIURETIC DRUGS — the group Oleander interacts with.

Theoretically, diuretic drugs may increase the risk of oleander toxicity.
Concomitant use of potassium depleting diuretics and oleander can increase the risk of cardiac glycoside toxicity due to potassium depletion.
Severity Major Likelihood Probable Evidence D

Interaction 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..

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

First, the big picture: I really wouldn't use oleander at all. It's a toxic plant with no safe dose, and it acts on your heart much like digoxin. But here's how it specifically tangles with chlorthalidone. Chlorthalidone is a water pill that makes your kidneys flush out extra salt and water, and along the way it can also lower your potassium level.

That's the problem. Low potassium makes your heart far more sensitive to oleander's heart-affecting compounds, which raises the risk of dangerous, irregular heartbeats. This concern is based on how these two work together (pharmacology) rather than lots of human studies, but the potential outcome is serious enough that I'd treat it as real. Please don't combine them, and talk with your pharmacist or doctor before making any changes.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Burnham TH, ed. Drug Facts and Comparisons, Updated Monthly. Facts and Comparisons, St. Louis, MO.

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

Oleander Also Interacts With Other Medications

Oleander has 132 major, 23 moderate known drug interactions in our database — the Chlorthalidone one above is one of them. If you take anything else, check it against the full list below.

Major 132 Moderate 23 No known interaction 2,675 (incl. Chlorthalidone)
Taking anything else?

Check Another of Your Medications Against Oleander

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

From our Q&A

Questions About Oleander or Chlorthalidone

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

This page covers Oleander only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Chlorthalidone page lists 222 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), Dolomite (major) and Lithium (major).

By severity: 8 major · 190 moderate · 24 minor.

From our pharmacist’s overview on the Chlorthalidone page

“Chlorthalidone (Hygroton, Thalitone) lowers blood pressure by helping the kidneys shed salt and water, and that mechanism makes its supplement interactions worth genuine care. Most of the 222 ingredients on file either add to its blood-pressure-lowering effect or act as diuretics themselves, so pressure or potassium can fall further th…”

Reviewed by 2 · Jul 18, 2026

Open the Chlorthalidone interaction page

How much people look this up

Where Oleander and Chlorthalidone 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 Oleander
Top half

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

29 days ago today
Medication Chlorthalidone
Steady interest

#1,690 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 Oleander

What is Oleander?

  • Heart failure (traditional)
  • Cancer (investigational)
  • Skin conditions
  • Asthma (folk use)
  • Pain relief (folk use)

Oleander is a highly poisonous ornamental plant, and every part of it can cause life-threatening heart and nervous system effects, even in small amounts. There is no proven safe dose for self-use, and serious poisonings and deaths have occurred from teas, extracts, and accidental ingestion. We strongly advise against using oleander as a supplement.

Read the full Oleander monograph & all interactions
Medication

About Chlorthalidone

What Is Chlorthalidone Used For?

Brand names: Hygroton, Thalitone

Chlorthalidone is used to treat high blood pressure (hypertension) in adults. Lowering blood pressure reduces the risk of serious cardiovascular events, especially strokes and heart attacks. It can be used alone or combined with other blood pressure medicines.

Chlorthalidone is also used as an add-on treatment for edema (fluid buildup) caused by heart failure, liver cirrhosis, and kidney conditions including nephrotic syndrome, acute glomerulonephritis, and chronic renal failure. Thalitone is additionally indicated for edema associated with heart failure, liver cirrhosis, and renal disease including nephrotic syndrome.

See full Chlorthalidone drug information
Keep checking

Other Drugs & Oleander

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

132Major
23Moderate
0Minor
2,674No known interaction
132 Major 23 Moderate 2,674 No interaction
Major

132 interactions

Showing 60 of 132 major interactions — see all 132 on the Oleander page.

Moderate

23 interactions

No interaction 2,674 drugs checked — show the list

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

Showing the 60 most looked-up of 2,674 medications checked with no known interaction — see the full Oleander list.

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

Can you take Oleander with Chlorthalidone?
This is rated a major interaction, so the combination is best avoided unless your doctor or pharmacist has specifically told you otherwise. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Oleander and Chlorthalidone interaction?
We rate it Major. This is a clinically significant combination that is generally best avoided, or used only under the direct supervision of your physician or pharmacist.

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

Still Have a Question About Chlorthalidone and Oleander?

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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.