Drug & supplement interaction

Coltsfoot + Treprostinil (Inh)

Treprostinil (Inh) brand name: Tyvaso.

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

Treprostinil (Inh) falls into 2 drug categories that Coltsfoot can interact with; the most serious is rated moderate. Theoretically, excessive doses of coltsfoot may interfere with antihypertensive or cardiovascular therapy.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Coltsfoot and Treprostinil (Inh)

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

Why Are There 2 Interactions?

Coltsfoot interacts with whole categories of medication. Treprostinil (Inh) falls into 2 of those categories, so it can interact with Coltsfoot 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 Coltsfoot interacts with.

Theoretically, excessive doses of coltsfoot may interfere with antihypertensive or cardiovascular therapy.
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 short version for anyone using inhaled treprostinil (Tyvaso). This drug is a vasodilator, meaning it relaxes the blood vessels in your lungs to ease the pressure that makes you short of breath and tired. The concern on file is mostly theoretical: in large amounts, coltsfoot might nudge your blood pressure or cardiovascular balance in a way that doesn't line up neatly with your treatment. The evidence behind this is anecdotal, so it isn't a strong or well-proven warning.

My bigger worry with coltsfoot is actually the plant itself. Raw coltsfoot can contain liver-toxic compounds, which is reason enough to be cautious, especially when you're managing a serious lung condition. Please don't stop or change your Tyvaso, and check with your doctor or pharmacist before adding coltsfoot.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Wilson BE, Hobbs WN. Case report: pseudoephedrine-associated thyroid storm: thyroid hormone-catecholamine interactions. Am J Med Sci 1993;306:317-9. PubMed
Moderate

ANTICOAGULANT/ANTIPLATELET DRUGS

2 of 2

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

Concomitant use might increase the risk of bleeding due to decreased platelet aggregation. Coltsfoot has been reported to inhibit platelet aggregation; avoid concomitant use. Some of these drugs include aspirin, clopidogrel (Plavix), dalteparin (Fragmin), enoxaparin (Lovenox), heparin, ticlopidine (Ticlid), warfarin (Coumadin), 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

Here's the thing to know about pairing coltsfoot with your inhaled treprostinil (Tyvaso). Treprostinil doesn't just relax the blood vessels in your lungs, it also makes your platelets a little less sticky, which mildly reduces clotting. Coltsfoot has been reported to do something similar in lab studies. Stack the two together and, in theory, you could nudge up your risk of bruising or bleeding more easily, like nosebleeds, bleeding gums, or cuts that take longer to stop.

I want to be honest about how solid this is: this warning is based on how these substances behave in test-tube and animal work, not on real patient studies, so it's more caution than proven danger. Coltsfoot carries its own liver-safety concerns too. Before combining them, please check with your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Hwang SB, Chang MN, Garcia ML, et al. L-652,469--a dual receptor antagonist of platelet activating factor and dihydropyridines from Tussilago farfara L. Eur J Pharmacol 1987;141:269-81. 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

Coltsfoot Also Interacts With Other Medications

Coltsfoot has 373 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 373 No known interaction 2,457 (incl. Treprostinil (Inh))
Taking anything else?

Check Another of Your Medications Against Coltsfoot

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

Everything else you take

See Every Supplement That Interacts With Treprostinil (Inh)

This page covers Coltsfoot 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 Coltsfoot as Part of a Dietary Supplement Product? Check It for Interactions

We hold 60 real supplement products containing Coltsfoot, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Coltsfoot. Your product may carry other ingredients that interact with Treprostinil (Inh) too, on top of Coltsfoot — 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 Coltsfoot 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 Coltsfoot
Top half

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

29 days ago today
Medication Treprostinil (Inh)
Top 25%

#627 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 Coltsfoot

What is Coltsfoot?

Coltsfoot
  • Cough
  • Sore throat
  • Bronchitis and congestion
  • Loosening mucus (expectorant)
  • Asthma symptoms

Coltsfoot is a traditional herb long used to soothe coughs and clear mucus, but solid human evidence for these uses is lacking. More importantly, the raw plant can contain liver-toxic pyrrolizidine alkaloids, so it carries real safety concerns and is best avoided unless you use a product certified to be free of these compounds.

Read the full Coltsfoot 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 & Coltsfoot

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

0Major
373Moderate
0Minor
2,456No known interaction
373 Moderate 2,456 No interaction
Moderate

373 interactions

Showing 60 of 373 moderate interactions — see all 373 on the Coltsfoot page.

No interaction 2,456 drugs checked — show the list

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

Showing the 60 most looked-up of 2,456 medications checked with no known interaction — see the full Coltsfoot list.

See the full Coltsfoot 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
Coltsfoot 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 Coltsfoot and Treprostinil (Inh) Together: Common Questions

Can you take Coltsfoot 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 Coltsfoot and Treprostinil (Inh)?
Treprostinil (Inh) belongs to more than one drug category, and Coltsfoot 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 Coltsfoot 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

Still Have a Question About Treprostinil (Inh) and Coltsfoot?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.