Drug & supplement interaction

Phellodendron + Naltrexone Hydrochloride, Oxycodone Hydrochloride

Naltrexone Hydrochloride, Oxycodone Hydrochloride brand name: Troxyca ER.

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

Naltrexone Hydrochloride, Oxycodone Hydrochloride falls into 2 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
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Phellodendron and Naltrexone Hydrochloride, Oxycodone Hydrochloride

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

Why Are There 2 Interactions?

Phellodendron interacts with whole categories of medication. Naltrexone Hydrochloride, Oxycodone Hydrochloride falls into 2 of those categories, so it can interact with Phellodendron in 2 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 2

Why this applies to Naltrexone Hydrochloride, Oxycodone Hydrochloride

Naltrexone Hydrochloride, Oxycodone Hydrochloride 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

Troxyca ER pairs oxycodone, a strong opioid painkiller, with naltrexone (which is built in to discourage misuse). The oxycodone part already brings drowsiness, slowed breathing, dizziness, and confusion on its own. Phellodendron contains berberine, and in animal studies berberine has shown mild sedative effects. So in theory, stacking it on top of this opioid could add to that sleepiness or sluggish feeling.

I want to be honest about the evidence here: this concern is based on pharmacology and lab data, not real human reports, so it's more a caution than a proven problem. Still, since any extra sedation with an opioid matters, please check with your pharmacist or doctor before combining the two rather than changing anything yourself.

Contact Dr. Brian directly if you have additional questions on this interaction
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 2D6 (CYP2D6) SUBSTRATES

2 of 2

Naltrexone Hydrochloride, Oxycodone Hydrochloride also falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES.

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP2D6.
Phellodendron contains berberine. In vitro research and preliminary clinical evidence show that berberine can inhibit CYP2D6. Theoretically, phellodendron might also inhibit CYP2D6.
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 gist for Troxyca ER (oxycodone paired with naltrexone). Your body uses an enzyme called CYP2D6 to help process oxycodone. Phellodendron contains berberine, which lab studies and some early human data suggest can slow that enzyme down. In theory, that could let oxycodone linger a bit longer and build up, which might mean stronger opioid effects like extra drowsiness, dizziness, constipation, or slowed breathing.

One thing to keep in mind: this concern is theoretical, based on how things work in the lab, not on solid real-world reports. Still, since opioids are serious medicine, I'd run any Phellodendron supplement past your pharmacist or doctor first rather than starting it on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Chatterjee P, Franklin MR. Human cytochrome p450 inhibition and metabolic-intermediate complex formation by goldenseal extract and its methylenedioxyphenyl components. Drug Metab Dispos 2003;31:1391-7. PubMed
  2. 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
  3. 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

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 Naltrexone Hydrochloride, Oxycodone Hydrochloride one above is among them. If you take anything else, check it against the full list below.

Moderate 1,159 No known interaction 1,671 (incl. Naltrexone Hydrochloride, Oxycodone Hydrochloride)
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 Naltrexone Hydrochloride, Oxycodone Hydrochloride

This page covers Phellodendron only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Naltrexone Hydrochloride, Oxycodone Hydrochloride page lists 145 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: 8 major · 114 moderate · 23 minor.

From our pharmacist’s overview on the Naltrexone Hydrochloride, Oxycodone Hydrochloride page

“Alcohol tops this list. Beer and wine both carry major, well-documented interactions with Troxyca ER (naltrexone and oxycodone hydrochloride), an extended-release opioid, because adding a second sedative to an opioid can slow breathing, not just deepen drowsiness.”

Reviewed by 2 · Jul 18, 2026

Open the Naltrexone Hydrochloride, Oxycodone Hydrochloride 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 Naltrexone Hydrochloride, Oxycodone Hydrochloride 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 Naltrexone Hydrochloride, Oxycodone Hydrochloride 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%

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

29 days ago today
Medication Naltrexone Hydrochloride, Oxycodone Hydrochloride
Steady interest

#1,652 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
1,159 Moderate 1,670 No 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

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

Showing the 60 most looked-up of 1,670 medications checked with no known interaction — see the full Phellodendron list.

See the full Phellodendron interactions page
See every supplement checked against Naltrexone Hydrochloride, Oxycodone Hydrochloride, 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
Phellodendron monograph › Uses, safety, and every drug interaction in one place Naltrexone Hydrochloride, Oxycodone Hydrochloride supplement interactions › Every supplement checked against Naltrexone Hydrochloride, Oxycodone Hydrochloride, 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 Phellodendron and Naltrexone Hydrochloride, Oxycodone Hydrochloride Together: Common Questions

Can you take Phellodendron with Naltrexone Hydrochloride, Oxycodone Hydrochloride?
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 Phellodendron and Naltrexone Hydrochloride, Oxycodone Hydrochloride?
Naltrexone Hydrochloride, Oxycodone Hydrochloride 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 Naltrexone Hydrochloride, Oxycodone Hydrochloride 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 Naltrexone Hydrochloride, Oxycodone Hydrochloride and Phellodendron?

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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.