Drug & supplement interaction

Oregon Grape + Treprostinil (Inh)

Treprostinil (Inh) brand name: Tyvaso.

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

Treprostinil (Inh) falls into 2 drug categories that Oregon Grape can interact with; the most serious is rated moderate. Theoretically, Oregon grape might increase the risk of hypotension when taken with antihypertensive drugs.

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

Oregon Grape and Treprostinil (Inh)

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

Why Are There 2 Interactions?

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

Moderate

ANTIHYPERTENSIVE DRUGS

1 of 2

Why this applies to Treprostinil (Inh)

Treprostinil (Inh) falls under ANTIHYPERTENSIVE DRUGS — the group Oregon Grape interacts with.

Theoretically, Oregon grape might increase the risk of hypotension when taken with antihypertensive drugs.
Animal research suggests that berberine, a constituent of Oregon grape, can have hypotensive effects. Also, an analysis of clinical evidence suggests that taking berberine in combination with amlodipine (Norvasc) can lower systolic and diastolic blood pressure when compared with taking amlodipine alone.
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 your inhaled treprostinil (Tyvaso): it's a vasodilator, meaning it relaxes and widens blood vessels. Oregon grape contains berberine, which in animal studies seems to have a mild blood-pressure-lowering effect of its own. Stack the two together and, in theory, you could see a bit more of a drop in blood pressure than you'd expect from treprostinil alone.

In real life, that might show up as feeling dizzy, lightheaded (especially standing up), flushed, or extra tired. I'll be honest though, this warning rests on lab and animal data plus a small study using a different medication, so it's more of a theoretical caution than a proven problem. Since treprostinil is a serious drug for a serious condition, please check with your pharmacist or doctor before adding Oregon grape.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Sabir M and Bhide NK. Study of some pharmacological actions of berberine. Ind J Physiol & Pharmac 1971;15(3):111-132.
  2. Chun YT, Yip TT, Lau KL, and et al. A biochemical study on the hypotensive effect of berberine in rats. Gen Pharmac 1979;10:177-182. PubMed
  3. Lan J, Zhao Y, Dong F, et al. Meta-analysis of the effect and safety of berberine in the treatment of type 2 diabetes mellitus, hyperlipemia and hypertension. J Ethnopharmacol. 2015;161:69-81. PubMed
Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

2 of 2

Treprostinil (Inh) also falls under ANTICOAGULANT/ANTIPLATELET DRUGS.

Theoretically, Oregon grape might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.
In vitro and in vivo research suggests that berberine, a constituent of Oregon grape, can inhibit platelet aggregation.
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 connection with your inhaled treprostinil (Tyvaso). Besides relaxing the blood vessels in your lungs, treprostinil also makes your platelets a little less sticky, which is its own mild blood-thinning effect. Oregon grape contains berberine, and in lab and animal studies that compound also seems to slow platelets down. Stack the two and, in theory, you could bruise or bleed more easily.

I want to keep this in perspective. The evidence here is weak, coming only from test-tube and animal work, not from people, so this is more of a caution than a proven problem. Treprostinil is not a prodrug, so nothing gets activated or blocked in a tricky way. Still, watch for easy bruising, nosebleeds, or bleeding gums, and check with your pharmacist or doctor before adding Oregon grape.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Wu, J. F. and Liu, T. P. [Effects of berberine on platelet aggregation and plasma levels of TXB2 and 6-keto-PGF1 alpha in rats with reversible middle cerebral artery occlusion]. Yao Xue.Xue.Bao. 1995;30(2):98-102.
  2. Tripathi YB and Shukla SD. Berberis artistata inhibits PAF induced aggregation of rabbit platelets. Phytotherapy Research 1996;10:628-630.

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

Oregon Grape Also Interacts With Other Medications

Oregon Grape has 1,217 moderate known drug interactions in our database — the Treprostinil (Inh) one above is among them. If you take anything else, check it against the full list below.

Moderate 1,217 No known interaction 1,613 (incl. Treprostinil (Inh))
Taking anything else?

Check Another of Your Medications Against Oregon Grape

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

Everything else you take

See Every Supplement That Interacts With Treprostinil (Inh)

This page covers Oregon Grape only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Treprostinil (Inh) page lists 275 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: American Hellebore (major), American Mistletoe (major), Danshen (major), Piracetam (major) and Tyramine (major).

By severity: 5 major · 251 moderate · 19 minor.

From our pharmacist’s overview on the Treprostinil (Inh) page

“Inhaled treprostinil (Tyvaso) relaxes blood vessels in the lungs to treat pulmonary hypertension, and it also blunts platelet clotting, which is why this list of 275 ingredients warrants real vigilance rather than a shrug. Two themes cover almost everything.”

Reviewed by 2 · Jul 18, 2026

Open the Treprostinil (Inh) interaction page

One more smart check

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

We hold 740 real supplement products containing Oregon Grape, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Oregon Grape. Your product may carry other ingredients that interact with Treprostinil (Inh) too, on top of Oregon Grape — 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 Oregon Grape and Treprostinil (Inh) 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 Oregon Grape
Top 25%

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

29 days ago today
Medication Treprostinil (Inh)
Steady interest

#2,393 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 Oregon Grape

What is Oregon Grape?

Oregon Grape
  • Psoriasis (topical)
  • Eczema and other skin conditions
  • Digestive upset
  • Mild skin infections
  • General 'detox' or tonic use

Oregon grape is a shrub whose root contains berberine and related compounds. The strongest (though still modest) evidence is for topical creams that may slightly ease psoriasis; evidence for other uses is limited. Talk with your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Read the full Oregon Grape monograph & all interactions
Medication

About Treprostinil Oral Inhalation

What Is Treprostinil Oral Inhalation Used For?

Brand name: Tyvaso

Treprostinil oral inhalation is used to treat two serious lung conditions that raise pressure in the blood vessels of the lungs. It helps improve how much physical activity you can do.

Tyvaso inhalation solution and Tyvaso DPI are both indicated to treat pulmonary arterial hypertension (PAH; WHO Group 1) and pulmonary hypertension associated with interstitial lung disease (PH-ILD; WHO Group 3). Clinical studies establishing effectiveness in PAH primarily included patients with moderate symptoms (NYHA Class III) whose PAH was idiopathic, heritable, or related to connective tissue disease. Studies in PH-ILD primarily included patients with idiopathic interstitial pneumonia, combined pulmonary fibrosis and emphysema, or connective tissue disease-related lung disease.

See full Treprostinil Oral Inhalation drug information
Keep checking

Other Drugs & Oregon Grape

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

0Major
1,217Moderate
0Minor
1,612No known interaction
1,217 Moderate 1,612 No interaction
Moderate

1,217 interactions

Showing 60 of 1,217 moderate interactions — see all 1,217 on the Oregon Grape page.

No interaction 1,612 drugs checked — show the list

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

Showing the 60 most looked-up of 1,612 medications checked with no known interaction — see the full Oregon Grape list.

See the full Oregon Grape interactions page
See every supplement checked against Treprostinil (Inh), 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
Oregon Grape monograph › Uses, safety, and every drug interaction in one place Treprostinil (Inh) supplement interactions › Every supplement checked against Treprostinil (Inh), ranked by severity Treprostinil Oral Inhalation 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 Oregon Grape and Treprostinil (Inh) Together: Common Questions

Can you take Oregon Grape with Treprostinil (Inh)?
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 Oregon Grape and Treprostinil (Inh)?
Treprostinil (Inh) belongs to more than one drug category, and Oregon Grape 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 Oregon Grape and Treprostinil (Inh) 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.