Drug & supplement interaction

Uva Ursi + Fedratinib Hydrochloride

Fedratinib Hydrochloride brand name: Inrebic.

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

Fedratinib Hydrochloride falls into 2 drug categories that Uva Ursi can interact with; the most serious is rated moderate. Theoretically, uva ursi may decrease the metabolism of CYP2C19 substrates.

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

Uva Ursi and Fedratinib Hydrochloride

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

Why Are There 2 Interactions?

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

Moderate

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES

1 of 2

Why this applies to Fedratinib Hydrochloride

Fedratinib Hydrochloride falls under CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES — the group Uva Ursi interacts with.

Theoretically, uva ursi may decrease the metabolism of CYP2C19 substrates.
In vitro, uva ursi appears to inhibit cytochrome CYP2C19. This effect has not been reported in humans.
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 with fedratinib (Inrebic) and uva ursi. Your body partly relies on a liver enzyme called CYP2C19 to clear fedratinib. In lab dish studies, uva ursi seemed to slow that same enzyme down. If that held true in people, fedratinib could clear more slowly and build up, which might mean more of its usual side effects, things like nausea, diarrhea, vomiting, tiredness, and changes in blood counts.

I want to be honest about the strength here: this is theoretical, seen only in test-tube work, never confirmed in humans. Still, fedratinib is a serious cancer medicine with real toxicity concerns, so I wouldn't add uva ursi without checking first. Please run it by your oncologist or pharmacist before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Chauhan B, Yu C, Krantis A, et al. In vitro activity of uva-ursi against cytochrome P450 isoenzymes and P-glycoprotein. Can J Physiol Pharmacol. 2007;85(11):1099-107.
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 2

Fedratinib Hydrochloride also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, uva ursi may decrease the metabolism of CYP3A4 substrates.
In vitro, uva ursi appears to inhibit CYP3A4. This effect has not been reported in humans.
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 fedratinib (Inrebic). Your body relies on a liver enzyme called CYP3A4 to clear this medicine out of your system. In lab dish studies, uva ursi seemed to slow that same enzyme down. If that held true in people, fedratinib could build up a bit higher than expected, which might mean more of its usual side effects like nausea, diarrhea, vomiting, fatigue, or changes in your blood counts and liver tests.

I want to be honest, though: this concern comes only from test tube data and hasn't actually been seen in humans, so it's more theoretical than proven. Still, fedratinib is a serious cancer drug, so please loop in your oncology team or pharmacist before adding uva ursi.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Chauhan B, Yu C, Krantis A, et al. In vitro activity of uva-ursi against cytochrome P450 isoenzymes and P-glycoprotein. Can J Physiol Pharmacol. 2007;85(11):1099-107.

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

Uva Ursi Also Interacts With Other Medications

Uva Ursi has 739 moderate, 63 minor known drug interactions in our database — the Fedratinib Hydrochloride one above is among them. If you take anything else, check it against the full list below.

Moderate 739 Minor 63 No known interaction 2,028 (incl. Fedratinib Hydrochloride)
Taking anything else?

Check Another of Your Medications Against Uva Ursi

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

Everything else you take

See Every Supplement That Interacts With Fedratinib Hydrochloride

This page covers Uva Ursi only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Fedratinib Hydrochloride page lists 173 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 129 moderate · 38 minor.

From our pharmacist’s overview on the Fedratinib Hydrochloride page

“People taking fedratinib (Inrebic) for myelofibrosis, a bone marrow cancer, often reach for supplements to help with fatigue, sleep, or appetite, and this is a list that warrants real care before adding any of them. Six of the 173 ingredients on file are rated major, and the dominant theme, covering 121 of them, is the CYP3A4 enzyme th…”

Reviewed by 2 · Jul 18, 2026

Open the Fedratinib Hydrochloride interaction page

One more smart check

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

We hold 1,423 real supplement products containing Uva Ursi, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Uva Ursi. Your product may carry other ingredients that interact with Fedratinib Hydrochloride too, on top of Uva Ursi — 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 Uva Ursi and Fedratinib 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 Uva Ursi
Top 25%

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

29 days ago today
Medication Fedratinib Hydrochloride
Top half

#735 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 Uva Ursi

What is Uva Ursi?

Uva Ursi
  • Urinary tract infections
  • Urinary discomfort
  • Mild diuretic
  • Kidney stones
  • Skin conditions

Uva ursi is a traditional herb used mainly for urinary tract infections, and its leaves contain a compound called arbutin that may have antimicrobial effects in the urine. Evidence in people is limited, and because high doses or long-term use may be harmful to the liver and could be toxic, it should only be used short-term and with guidance from a healthcare professional. Avoid it during pregnancy and breastfeeding.

Read the full Uva Ursi monograph & all interactions
Medication

About Fedratinib

What Is Fedratinib Used For?

Brand name: Inrebic

Inrebic (fedratinib) is approved to treat adult patients with intermediate-2 or high-risk myelofibrosis (MF) — a type of bone marrow cancer that disrupts normal blood cell production. This includes primary myelofibrosis as well as secondary myelofibrosis that developed after polycythemia vera or essential thrombocythemia.

It is used both in patients who have not been treated before and in those who have previously been treated with ruxolitinib, another myelofibrosis medication.

See full Fedratinib drug information
Keep checking

Other Drugs & Uva Ursi

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

0Major
739Moderate
63Minor
2,027No known interaction
739 Moderate 63 Minor 2,027 No interaction
Moderate

739 interactions

Showing 60 of 739 moderate interactions — see all 739 on the Uva Ursi page.

Minor

63 interactions

Showing 60 of 63 minor interactions — see all 63 on the Uva Ursi page.

No interaction 2,027 drugs checked — show the list

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

Showing the 60 most looked-up of 2,027 medications checked with no known interaction — see the full Uva Ursi list.

See the full Uva Ursi interactions page
See every supplement checked against Fedratinib 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
Uva Ursi monograph › Uses, safety, and every drug interaction in one place Fedratinib Hydrochloride supplement interactions › Every supplement checked against Fedratinib Hydrochloride, ranked by severity Fedratinib 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 Uva Ursi and Fedratinib Hydrochloride Together: Common Questions

Can you take Uva Ursi with Fedratinib 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 Uva Ursi and Fedratinib Hydrochloride?
Fedratinib Hydrochloride belongs to more than one drug category, and Uva Ursi 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 Uva Ursi and Fedratinib 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 Fedratinib Hydrochloride and Uva Ursi?

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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.