Drug & supplement interaction

Evodia + Grepafloxacin

Grepafloxacin brand name: Raxar.

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

Grepafloxacin falls into 2 drug categories that Evodia can interact with; the most serious is rated moderate. Evodia might reduce the levels and clinical effects of CYP1A2 substrates through induction of CYP1A2.

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

Evodia and Grepafloxacin

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

Why Are There 2 Interactions?

Evodia interacts with whole categories of medication. Grepafloxacin falls into 2 of those categories, so it can interact with Evodia 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 1A2 (CYP1A2) SUBSTRATES

1 of 2

Why this applies to Grepafloxacin

Grepafloxacin falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Evodia interacts with.

Evodia might reduce the levels and clinical effects of CYP1A2 substrates through induction of CYP1A2.
Evodia extract and the evodia constituent rutaecarpine induce hepatic CYP1A2 enzyme activity. Evodia decreases levels of theophylline and caffeine, CYP1A2 substrates, by about 70% in animal models.
Severity Moderate Likelihood Probable Evidence D

Interaction 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..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist for grepafloxacin (Raxar), an antibiotic that your liver partly clears using an enzyme called CYP1A2. Evodia appears to speed that enzyme up. In animal and test-tube studies, an evodia compound called rutaecarpine ramped up CYP1A2 activity and dropped levels of similar drugs by roughly 70 percent.

If the same thing happened with grepafloxacin, your body could clear it faster and leave less drug available to fight your infection. That matters with an antibiotic, since underdosing can mean the bug isn't fully knocked out. That said, this is weak, lab-and-animal evidence, not proven in people. Grepafloxacin was also pulled from the market years ago. If you're using either, please check with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Ueng YF, Tsai TH, Don MJ, et al. Alteration of the pharmacokinetics of theophylline by rutaecarpine, an alkaloid of the medicinal herb Evodia rutaecarpa, in rats. J Pharm Pharmacol 2005;57:227-32.
  2. Ueng YF, Jan WC, Lin LC, et al. The alkaloid rutaecarpine is a selective inhibitor of cytochrome P450 1A in mouse and human liver microsomes. Drug Metab Dispos 2002;30:349-53. PubMed
  3. Tsai TH, Chang CH, Lin LC. Effects of Evodia rutaecarpa and rutaecarpine on the pharmacokinetics of caffeine in rats. Planta Med 2005;71:640-5.
  4. Lee SK, Kim NH, Lee J, et al. Induction of cytochrome P450s by rutaecarpine and metabolism of rutaecarpine by cytochrome P450s. Planta Med 2004;70:753-7. PubMed
Moderate

QT INTERVAL-PROLONGING DRUGS

2 of 2

Grepafloxacin also falls under QT INTERVAL-PROLONGING DRUGS.

Theoretically, evodia might have an additive effect with drugs that prolong the QT interval, potentially increasing the risk of ventricular arrhythmias.
Evodia has demonstrated dose-dependent activity as a proarrhythmic agent in animal and in vitro studies. Evodia infusion in animals extends the action duration potential and induces prolongation of the QT interval and Torsade de pointes.
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 concern with pairing Evodia and Grepafloxacin. Grepafloxacin is a fluoroquinolone antibiotic that's well known for affecting your heart's electrical rhythm, something doctors call QT interval prolongation. In fact, this drug was pulled from the market years ago largely because of that heart rhythm risk. Lab and animal studies suggest Evodia may do something similar, so stacking the two together could, in theory, add up and raise the chance of a dangerous irregular heartbeat (including a type called Torsade de pointes).

I want to be honest that this is theoretical and based only on test tube and animal research, not human studies, so don't panic. Still, because heart rhythm is involved, it's worth checking with your pharmacist or doctor before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Baburin I, Varkvisser R, Schramm A, et al. Dehydroevodiamine and hortiamine, alkaloids from the traditional Chinese herbal drug Evodia rutaecarpa, are IKr blockers with proarrhythmic effects in vitro and in vivo. Pharmacol Res. 2018 May;131:150-163. DOI

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

Evodia Also Interacts With Other Medications

Evodia has 949 moderate known drug interactions in our database — the Grepafloxacin one above is among them. If you take anything else, check it against the full list below.

Moderate 949 No known interaction 1,881 (incl. Grepafloxacin)
Taking anything else?

Check Another of Your Medications Against Evodia

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

Everything else you take

See Every Supplement That Interacts With Grepafloxacin

This page covers Evodia only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Grepafloxacin page lists 164 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Apple (major), Arsenic (major) and Cesium (major).

By severity: 9 major · 113 moderate · 42 minor.

From our pharmacist’s overview on the Grepafloxacin page

“A week on grepafloxacin (Raxar), a quinolone antibiotic, often comes with juice at breakfast, coffee through the day, maybe a probiotic for the stomach, and each of those shows up on this list. The nine major entries among these 164 deserve your attention first: grapefruit and other fruit juices can block the transporter that carries t…”

Reviewed by 2 · Jul 18, 2026

Open the Grepafloxacin interaction page

One more smart check

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

We hold 182 real supplement products containing Evodia, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Evodia. Your product may carry other ingredients that interact with Grepafloxacin too, on top of Evodia — 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 Evodia and Grepafloxacin 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 Evodia
Top half

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

29 days ago today
Medication Grepafloxacin
Steady interest

#2,329 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 Evodia

What is Evodia?

  • Digestive upset and nausea
  • Headaches
  • Menstrual cramps
  • Abdominal pain
  • Diarrhea

Evodia is a fruit used in traditional Chinese medicine, most often for digestive complaints, headaches, and menstrual pain. Human evidence for these uses is very limited, and it is mostly studied in laboratory and animal research. Talk with a pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Read the full Evodia monograph & all interactions
Keep checking

Other Drugs & Evodia

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

0Major
949Moderate
0Minor
1,880No known interaction
949 Moderate 1,880 No interaction
Moderate

949 interactions

Showing 60 of 949 moderate interactions — see all 949 on the Evodia page.

No interaction 1,880 drugs checked — show the list

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

Showing the 60 most looked-up of 1,880 medications checked with no known interaction — see the full Evodia list.

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

Can you take Evodia with Grepafloxacin?
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 Evodia and Grepafloxacin?
Grepafloxacin belongs to more than one drug category, and Evodia 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 Evodia and Grepafloxacin 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.