Drug & supplement interaction

Marsh Labrador Tea + Methsuximide

Methsuximide brand name: Celontin.

Moderate Interaction
The bottom line Moderate

Marsh Labrador Tea has a moderate interaction with Methsuximide. Marsh Labrador tea can potentiate effects of barbiturates and alcohol.

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

Marsh Labrador Tea and Methsuximide

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

Moderate

CNS DEPRESSANTS

Why this applies to Methsuximide

Methsuximide falls under CNS DEPRESSANTS — the group Marsh Labrador Tea interacts with.

Marsh Labrador tea can potentiate effects of barbiturates and alcohol.
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 simple version: Methsuximide (Celontin) is a seizure medicine that can already make you feel drowsy, foggy, or unsteady on your feet. Marsh Labrador tea has been noted to add to the calming, sedating effects of things like alcohol and barbiturates. Since Methsuximide works in that same general lane of slowing down brain activity, combining the two could leave you more tired, dizzy, or slowed in your thinking than usual.

I want to be honest about the strength of this concern. This is a theoretical interaction, based on how the plant behaves rather than solid human studies. On top of that, Marsh Labrador tea contains a natural toxin and isn't considered safe to take regularly anyway. Please check with your pharmacist or doctor before mixing the two, and don't change your Methsuximide on your own.

References
  1. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 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

Marsh Labrador Tea Also Interacts With Other Medications

Marsh Labrador Tea has 247 moderate known drug interactions in our database — the Methsuximide one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Marsh Labrador Tea

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

Everything else you take

See Every Supplement That Interacts With Methsuximide

This page covers Marsh Labrador Tea only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Methsuximide page lists 105 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Beer (major), Gamma-hydroxybutyrate (ghb) (major) and Kava (major).

By severity: 7 major · 82 moderate · 16 minor.

From our pharmacist’s overview on the Methsuximide page

“Methsuximide (Celontin) treats absence seizures by quieting overactive brain signals, so anything else that slows the nervous system deserves genuine respect before you take it alongside. Of the 105 supplements and herbs on record, 78 add sedation on top of what the drug already does, and that group holds most of the 7 major-rated entr…”

Reviewed by 2 · Jul 18, 2026

Open the Methsuximide interaction page

How much people look this up

Where Marsh Labrador Tea and Methsuximide 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 Marsh Labrador Tea
Steady interest

#1,327 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Methsuximide
Top half

#1,389 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 Marsh Labrador Tea

What is Marsh Labrador Tea?

Marsh Labrador Tea
  • Colds and respiratory complaints
  • Cough and congestion
  • Mild aches and joint discomfort
  • Topical relief of skin irritation, swelling, and insect bites
  • Traditional use as a diuretic

Marsh Labrador tea is a bog-growing shrub used in folk medicine for coughs, colds, and skin problems, but high-quality human evidence for any use is lacking. Because it contains grayanotoxins (andromedotoxin) that can be poisonous, it is not considered safe for routine use, and pregnant or breastfeeding people should avoid it.

Read the full Marsh Labrador Tea monograph & all interactions
Medication

About Methsuximide

What Is Methsuximide Used For?

Brand name: Celontin

Methsuximide is used to control absence (petit mal) seizures — brief episodes of staring or lapses in consciousness — when other seizure medications have not worked. Both Celontin and the generic methsuximide capsules carry this indication.

It can also be used alongside other antiseizure medications when a person has absence seizures together with other types of epilepsy.

See full Methsuximide drug information
Keep checking

Other Drugs & Marsh Labrador Tea

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

0Major
247Moderate
0Minor
2,582No known interaction
Moderate

247 interactions

Showing 60 of 247 moderate interactions — see all 247 on the Marsh Labrador Tea page.

No interaction 2,582 drugs checked — show the list
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

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Pharmacist Counseling Corner

Taking Marsh Labrador Tea and Methsuximide Together: Common Questions

Can you take Marsh Labrador Tea with Methsuximide?
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 Marsh Labrador Tea and Methsuximide 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

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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.