Drug & supplement interaction

Phellodendron + Belladonna, Caffeine, Ergotamine, Pentobarbital

Belladonna, Caffeine, Ergotamine, Pentobarbital brand name: Micomp PB.

Moderate Interaction
The bottom line Moderate

Belladonna, Caffeine, Ergotamine, Pentobarbital falls into 3 drug categories that Phellodendron can interact with; the most serious is rated moderate. Theoretically, phellodendron might increase the sedative effects of CNS depressants.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Phellodendron and Belladonna, Caffeine, Ergotamine, Pentobarbital

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Phellodendron interacts with whole categories of medication. Belladonna, Caffeine, Ergotamine, Pentobarbital falls into 3 of those categories, so it can interact with Phellodendron in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CNS DEPRESSANTS

1 of 3

Why this applies to Belladonna, Caffeine, Ergotamine, Pentobarbital

Belladonna, Caffeine, Ergotamine, Pentobarbital falls under CNS DEPRESSANTS — the group Phellodendron interacts with.

Theoretically, phellodendron might increase the sedative effects of CNS depressants.
Phellodendron contains berberine. Animal research suggests that berberine may have sedative effects. Theoretically, phellodendron might also have CNS depressants effects.
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

This combination product (sold as Micomp PB) contains pentobarbital, a barbiturate that calms the nervous system, along with belladonna, caffeine, and ergotamine. The piece that matters here is the pentobarbital. Phellodendron contains berberine, and in animal studies berberine has shown mild sedating effects. So the concern is simple: stacking phellodendron on top of pentobarbital could add to the drowsiness, making you feel more groggy, sleepy, dizzy, or slow to react.

I want to be straight with you though, this is a theoretical caution based on lab and animal data, not real human cases, so it's a maybe and not a sure thing. Still, since this medicine already has a sedative in it, check with your pharmacist or doctor before pairing the two, especially before driving.

References
  1. Janbaz KH, Gilani AH. Studies on preventive and curative effects of berberine on chemical-induced hepatotoxicity in rodents. Fitoterapia 2000;71:25-33.. PubMed
  2. Shanbhag, S. M., Kulkarni, H. J., and Gaitonde, B. B. Pharmacological actions of berberine on the central nervous system. Jpn.J Pharmacol 1970;20(4):482-487. PubMed
  3. Peng, W. H., Hsieh, M. T., and Wu, C. R. Effect of long-term administration of berberine on scopolamine-induced amnesia in rats. Jpn J Pharmacol 1997;74(3):261-266. DOI
  4. Sabir M and Bhide NK. Study of some pharmacological actions of berberine. Ind J Physiol & Pharmac 1971;15(3):111-132.
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 3

Belladonna, Caffeine, Ergotamine, Pentobarbital also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP3A4.
Phellodendron contains berberine. In vitro research and preliminary clinical research show that berberine moderately inhibits CYP3A4. Theoretically, phellodendron might also inhibit CYP3A4.
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

This combination pill has a lot going on, but the piece to watch with phellodendron is the ergotamine. Ergotamine, used to treat migraines, is cleared by a liver enzyme called CYP3A4. Phellodendron contains berberine, which lab and early human studies suggest can mildly slow that same enzyme down. In theory, that could let ergotamine build up a bit more than usual.

If ergotamine levels climb too high, it can cause problems like nausea, leg or arm tingling, cold or numb fingers and toes, and tighter blood vessels. The good news is this warning is theoretical, based on how the chemicals behave, not on real-world reports. Still, since ergotamine has a narrow safety margin, I'd run this by your pharmacist or doctor before mixing the two.

References
  1. Wu X, Li Q, Xin H, Yu A, Zhong M. Effects of berberine on the blood concentration of cyclosporin A in renal transplanted recipients: clinical and pharmacokinetic study. Eur J Clin Pharmacol 2005;61:567-72. PubMed
  2. Budzinski JW, Foster BC, Vandenhoek S, Arnason JT. An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine 2000;7:273-82. PubMed
  3. Guo, Y., Chen, Y., Tan, Z. R., Klaassen, C. D., and Zhou, H. H. Repeated administration of berberine inhibits cytochromes P450 in humans. Eur J Clin Pharmacol 2012;68(2):213-217. PubMed
  4. Hermann, R. and von, Richter O. Clinical evidence of herbal drugs as perpetrators of pharmacokinetic drug interactions. Planta Med 2012;78(13):1458-1477. PubMed
Moderate

PENTOBARBITAL (Nembutal)

3 of 3
Theoretically, phellodendron might increase the sedative effect of pentobarbital.
Phellodendron contains berberine. Animal research shows that berberine can prolong pentobarbital-induced sleeping time. Theoretically, phellodendron might increase the sedative effects of pentobarbital.
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

This combination product (Micomp PB) contains pentobarbital, a barbiturate sedative, along with belladonna, caffeine, and ergotamine. The piece that matters here is the pentobarbital. Phellodendron contains berberine, and in animal studies berberine made barbiturate-type sleep last longer. So in theory, pairing the two could deepen or extend the calming, drowsy effect of the pentobarbital part.

If that happened, you might feel more sleepy, foggy, dizzy, or unusually slowed down. I want to be honest though: this is a theoretical concern based on lab and animal work, not on solid human studies. It's worth a quick chat with your pharmacist or doctor before combining them, especially since this medicine already affects how alert you feel. Please don't stop or change anything on your own.

References
  1. Janbaz KH, Gilani AH. Studies on preventive and curative effects of berberine on chemical-induced hepatotoxicity in rodents. Fitoterapia 2000;71:25-33.. PubMed

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

Phellodendron Also Interacts With Other Medications

Phellodendron has 1,159 moderate known drug interactions in our database — the Belladonna, Caffeine, Ergotamine, Pentobarbital one above is among them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Phellodendron

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

Everything else you take

See Every Supplement That Interacts With Belladonna, Caffeine, Ergotamine, Pentobarbital

This page covers Phellodendron only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Belladonna, Caffeine, Ergotamine, Pentobarbital page lists 290 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), Ephedra (major) and Gamma-hydroxybutyrate (ghb) (major).

By severity: 15 major · 227 moderate · 48 minor.

From our pharmacist’s overview on the Belladonna, Caffeine, Ergotamine, Pentobarbital page

“People who take Micomp PB for migraines are often the same people reaching for an herbal sleep aid or a caffeinated energy product during a rough stretch, and with four drugs in one tablet (belladonna, caffeine, ergotamine, pentobarbital) nearly everything clashes with something. The 290 supplement ingredients on file here earn genuine…”

Reviewed by 2 · Jul 18, 2026

Open the Belladonna, Caffeine, Ergotamine, Pentobarbital interaction page

One more smart check

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

We hold 393 real supplement products containing Phellodendron, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Phellodendron. Your product may carry other ingredients that interact with Belladonna, Caffeine, Ergotamine, Pentobarbital too, on top of Phellodendron — 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 Phellodendron and Belladonna, Caffeine, Ergotamine, Pentobarbital 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 Phellodendron
Top 25%

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

29 days ago today
Medication Belladonna, Caffeine, Ergotamine, Pentobarbital
Steady interest

#1,478 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 Phellodendron

What is Phellodendron?

Phellodendron
  • Digestive complaints and diarrhea
  • Inflammation and joint discomfort
  • Stress and weight management (in combination products)
  • Skin conditions (topical, traditional)
  • Antimicrobial support

Phellodendron is a traditional Chinese medicine bark (Huang Bai) that contains berberine and other plant compounds with antimicrobial and anti-inflammatory activity in lab studies. Human evidence for most uses is limited, and it is often sold in combination with other herbs, making its individual effects hard to judge. Talk with your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Read the full Phellodendron monograph & all interactions
Keep checking

Other Drugs & Phellodendron

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

0Major
1,159Moderate
0Minor
1,670No known interaction
Moderate

1,159 interactions

Showing 60 of 1,159 moderate interactions — see all 1,159 on the Phellodendron page.

No interaction 1,670 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 Phellodendron and Belladonna, Caffeine, Ergotamine, Pentobarbital Together: Common Questions

Can you take Phellodendron with Belladonna, Caffeine, Ergotamine, Pentobarbital?
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 3 interactions listed for Phellodendron and Belladonna, Caffeine, Ergotamine, Pentobarbital?
Belladonna, Caffeine, Ergotamine, Pentobarbital belongs to more than one drug category, and Phellodendron 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 Phellodendron and Belladonna, Caffeine, Ergotamine, Pentobarbital 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.