Drug & supplement interaction

European Buckthorn + Methazolamide

Methazolamide brand name: Neptazane.

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

European Buckthorn has a moderate interaction with Methazolamide. European buckthorn has stimulant laxative effects.

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

European Buckthorn and Methazolamide

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

Moderate

DIURETIC DRUGS

Why this applies to Methazolamide

Methazolamide falls under DIURETIC DRUGS — the group European Buckthorn interacts with.

European buckthorn has stimulant laxative effects. Theoretically, overuse of European buckthorn might compound diuretic-induced potassium loss. There is some concern that taking European buckthorn along with potassium-depleting diuretics might increase the risk for hypokalemia.
Some diuretics that can deplete potassium include chlorothiazide (Diuril), chlorthalidone (Thalitone), furosemide (Lasix), hydrochlorothiazide (HCTZ, Hydrodiuril, Microzide), and 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 thing to keep an eye on with this combination. Methazolamide is a carbonic anhydrase inhibitor for glaucoma, and one of its known quirks is that it can lower your potassium level over time, much like a water pill does. European Buckthorn is a strong stimulant laxative, and laxatives like this can flush out potassium too. Stacked together, especially if you overuse the buckthorn, they could push your potassium lower than you'd want.

Low potassium can leave you feeling weak, tired, crampy, or give you an irregular heartbeat. This concern is theoretical, based on how each works rather than hard studies, so don't panic. Still, since safer constipation options exist, I'd check with your pharmacist or doctor before pairing these.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.

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

European Buckthorn Also Interacts With Other Medications

European Buckthorn has 1 major, 97 moderate known drug interactions in our database — the Methazolamide one above is one of them. If you take anything else, check it against the full list below.

Major 1 Moderate 97 No known interaction 2,732 (incl. Methazolamide)
Taking anything else?

Check Another of Your Medications Against European Buckthorn

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

Everything else you take

See Every Supplement That Interacts With Methazolamide

This page covers European Buckthorn only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Methazolamide page lists 218 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), Lithium (major) and Oleander (major).

By severity: 7 major · 187 moderate · 24 minor.

From our pharmacist’s overview on the Methazolamide page

“Methazolamide (Neptazane) treats glaucoma by lowering pressure inside the eye, and because it also has mild water-pill effects it can nudge blood pressure and potassium on its own. That is exactly where most of the 218 supplements on this page press, and the list earns real caution.”

Reviewed by 2 · Jul 18, 2026

Open the Methazolamide interaction page

One more smart check

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

We hold 20 real supplement products containing European Buckthorn, each one broken down to its full ingredient list — and combination products often carry several ingredients besides European Buckthorn. Your product may carry other ingredients that interact with Methazolamide too, on top of European Buckthorn — 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 European Buckthorn and Methazolamide 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 European Buckthorn
Steady interest

#1,399 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Methazolamide
Steady interest

#1,949 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 European Buckthorn

What is European Buckthorn?

  • Constipation
  • Occasional laxative use
  • Digestive complaints
  • Traditional 'detox' remedies

European Buckthorn is a shrub whose bark and berries contain compounds that act as a strong, irritant-type laxative. Because it can cause cramping, fluid and electrolyte loss, and the berries can be toxic if eaten raw, it is rarely recommended today and safer constipation options are usually preferred. Talk to a pharmacist or doctor before using it.

Read the full European Buckthorn monograph & all interactions
Medication

About Methazolamide

What Is Methazolamide Used For?

Brand name: Neptazane

Methazolamide tablets are used to treat eye conditions where lowering intraocular pressure (pressure inside the eye) is expected to help. These include chronic open-angle glaucoma, secondary glaucoma, and acute angle-closure glaucoma before surgery.

See full Methazolamide drug information
Keep checking

Other Drugs & European Buckthorn

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

1Major
97Moderate
0Minor
2,731No known interaction
1 Major 97 Moderate 2,731 No interaction
Major

1 interaction

Moderate

97 interactions

Showing 60 of 97 moderate interactions — see all 97 on the European Buckthorn page.

No interaction 2,731 drugs checked — show the list

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

Showing the 60 most looked-up of 2,731 medications checked with no known interaction — see the full European Buckthorn list.

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

Can you take European Buckthorn with Methazolamide?
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 European Buckthorn and Methazolamide 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 Methazolamide and European Buckthorn?

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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.