Drug & supplement interaction

Dendrobium + Ephedrine, Phenobarbital, Theophylline

Ephedrine, Phenobarbital, Theophylline brand name: Tedral.

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

Ephedrine, Phenobarbital, Theophylline falls into 2 drug categories that Dendrobium can interact with; the most serious is rated moderate. The dendrobium constituent dendrobine is reported to have convulsant effects.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Dendrobium and Ephedrine, Phenobarbital, Theophylline

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Dendrobium interacts with whole categories of medication. Ephedrine, Phenobarbital, Theophylline falls into 2 of those categories, so it can interact with Dendrobium in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

SEIZURE THRESHOLD LOWERING DRUGS

1 of 2

Why this applies to Ephedrine, Phenobarbital, Theophylline

Ephedrine, Phenobarbital, Theophylline falls under SEIZURE THRESHOLD LOWERING DRUGS — the group Dendrobium interacts with.

The dendrobium constituent dendrobine is reported to have convulsant effects. Theoretically, combining dendrobium with pro-convulsant drugs might increase the risk of seizure. Some drugs that lower the seizure threshold include anesthetics (propofol, others), antiarrhythmics (mexiletine), antibiotics (amphotericin, penicillin, cephalosporins, imipenem), antidepressants (bupropion, others), antihistamines (cyproheptadine, others), immunosuppressants (cyclosporine), narcotics (fentanyl, others), stimulants (methylphenidate), theophylline, 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

Tedral is a combination product, and two of its pieces matter here. Ephedrine is a stimulant and theophylline can rev up the nervous system too. Dendrobium contains a compound called dendrobine that, at least in lab and animal work, may make seizures easier to trigger. So in theory, pairing it with these stimulant-type ingredients could nudge your seizure risk up a bit, and might add to jitteriness, a racing heart, trouble sleeping, or feeling wired.

There's an interesting twist: phenobarbital is actually an anti-seizure medicine, so it may partly offset that concern. Honestly, this interaction is theoretical and based on pharmacology, not real patient reports, so I wouldn't panic. Still, please run it by your pharmacist or doctor before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Dr. Duke's Phytochemical and Ethnobotanical Databases. Available at: http://www.ars-grin.gov/duke/.
Moderate

ANTICONVULSANTS

2 of 2

Ephedrine, Phenobarbital, Theophylline also falls under ANTICONVULSANTS.

The dendrobium constituent dendrobine is reported to have convulsant effects. Theoretically, combining dendrobium with anticonvulsant drugs might decrease drug effectiveness and increase the risk of seizure. Some anticonvulsant drugs include phenobarbital, primidone (Mysoline), valproic acid (Depakene), gabapentin (Neurontin), carbamazepine (Tegretol), phenytoin (Dilantin), 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

Your Tedral combo includes phenobarbital, which calms overactive nerve signals and is sometimes used to prevent seizures. Here's the concern: Dendrobium contains a compound called dendrobine that, at least in lab settings, may actually trigger or worsen convulsions. So in theory, taking Dendrobium could work against phenobarbital and make a seizure more likely, especially if you rely on it for seizure control.

I want to be honest about the strength of this: it's theoretical, based on how the chemistry is expected to behave, not on real patient reports. Still, since seizures are serious and phenobarbital is sensitive to changes, I'd play it safe and skip the Dendrobium until you check with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Dr. Duke's Phytochemical and Ethnobotanical Databases. Available at: http://www.ars-grin.gov/duke/.

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

Dendrobium Also Interacts With Other Medications

Dendrobium has 460 moderate, 148 minor known drug interactions in our database — the Ephedrine, Phenobarbital, Theophylline one above is among them. If you take anything else, check it against the full list below.

Moderate 460 Minor 148 No known interaction 2,222 (incl. Ephedrine, Phenobarbital, Theophylline)
Taking anything else?

Check Another of Your Medications Against Dendrobium

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

Everything else you take

See Every Supplement That Interacts With Ephedrine, Phenobarbital, Theophylline

This page covers Dendrobium only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ephedrine, Phenobarbital, Theophylline page lists 184 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), Black Tea (major) and Caffeine (major).

By severity: 22 major · 140 moderate · 22 minor.

Open the Ephedrine, Phenobarbital, Theophylline interaction page

One more smart check

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

We hold 117 real supplement products containing Dendrobium, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Dendrobium. Your product may carry other ingredients that interact with Ephedrine, Phenobarbital, Theophylline too, on top of Dendrobium — 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 Dendrobium and Ephedrine, Phenobarbital, Theophylline 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 Dendrobium
Top half

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

29 days ago today
Medication Ephedrine, Phenobarbital, Theophylline
Steady interest

#2,762 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 Dendrobium

What is Dendrobium?

  • Dry mouth and thirst
  • Supporting digestion
  • General tonic/vitality
  • Eye and skin health
  • Recovery after illness

Dendrobium is a group of orchids long used in traditional Chinese medicine, often to moisten the body and as a general tonic. Human evidence for its modern health claims is very limited, so it should be viewed as a traditional remedy rather than a proven treatment. Talk to your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding because safety isn't known.

Read the full Dendrobium monograph & all interactions
Keep checking

Other Drugs & Dendrobium

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

0Major
460Moderate
148Minor
2,221No known interaction
460 Moderate 148 Minor 2,221 No interaction
Moderate

460 interactions

Showing 60 of 460 moderate interactions — see all 460 on the Dendrobium page.

Minor

148 interactions

Showing 60 of 148 minor interactions — see all 148 on the Dendrobium page.

No interaction 2,221 drugs checked — show the list

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

Showing the 60 most looked-up of 2,221 medications checked with no known interaction — see the full Dendrobium list.

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

Can you take Dendrobium with Ephedrine, Phenobarbital, Theophylline?
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.
Why are there 2 interactions listed for Dendrobium and Ephedrine, Phenobarbital, Theophylline?
Ephedrine, Phenobarbital, Theophylline belongs to more than one drug category, and Dendrobium interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Dendrobium and Ephedrine, Phenobarbital, Theophylline 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.