Drug & supplement interaction

Quercetin + Ciprofloxacin, Hydrocortisone

Ciprofloxacin, Hydrocortisone brand name: Cipro HC Otic.

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

Ciprofloxacin, Hydrocortisone falls into 2 drug categories that Quercetin can interact with; the most serious is rated moderate. Theoretically, concomitant use might increase the effects and adverse effects of OAT1 substrates.

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

Quercetin and Ciprofloxacin, Hydrocortisone

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

Why Are There 2 Interactions?

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

Moderate

ORGANIC ANION TRANSPORTER 1 (OAT1) SUBSTRATES

1 of 2

Why this applies to Ciprofloxacin, Hydrocortisone

Ciprofloxacin, Hydrocortisone falls under ORGANIC ANION TRANSPORTER 1 (OAT1) SUBSTRATES — the group Quercetin interacts with.

Theoretically, concomitant use might increase the effects and adverse effects of OAT1 substrates.

In vitro research shows that quercetin is a strong non-competitive inhibitor of OAT1, with half-maximal inhibitory concentration (IC50) values less than 10 mcM. So far, this interaction 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

The product you're asking about, Cipro HC Otic, is a combination of ciprofloxacin and hydrocortisone that goes directly into the ear as drops. The concern on file involves a kidney transporter called OAT1, which helps clear certain drugs out of the body. In lab dishes, quercetin blocks that transporter, which in theory could let an OAT1 drug build up and cause stronger effects or side effects.

Here's the reassuring part: this is theoretical only, based on test-tube work, and has never been reported in real people. Even more importantly, ear drops act locally and very little reaches your bloodstream, so a kidney-clearance interaction is very unlikely to matter here. If you ever take ciprofloxacin by mouth, just mention your quercetin to your pharmacist.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Ni Y, Duan Z, Zhou D, et al. Identification of Structural Features for the Inhibition of OAT3-Mediated Uptake of Enalaprilat by Selected Drugs and Flavonoids. Front Pharmacol. 2020;11:802. PubMed
Moderate

ORGANIC ANION-TRANSPORTING POLYPEPTIDE SUBSTRATES (OATP)

2 of 2

Ciprofloxacin, Hydrocortisone also falls under ORGANIC ANION-TRANSPORTING POLYPEPTIDE SUBSTRATES (OATP).

Theoretically, concomitant use might increase the effects and adverse effects of OATP substrates.

In vitro evidence shows that quercetin can inhibit organic anion-transporting peptide (OATP) 1B1-mediated uptake of estrone-3-sulfate and pravastatin. Furthermore, clinical research in healthy males shows that intake of quercetin along with pravastatin increases the AUC of pravastatin by 24%, prolongs its half-life by 14%, and decreases its apparent clearance by 18%, suggesting that quercetin modestly inhibits the uptake of pravastatin in hepatic cells.
Severity Moderate Likelihood Possible Evidence B

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

Good question, and here's some reassuring news. The product you're asking about, Cipro HC Otic, is an ear drop that combines ciprofloxacin (an antibiotic) with hydrocortisone (a steroid) to treat outer ear infections. The whole interaction on file is about quercetin blocking a liver transporter called OATP, which only matters for medicines that get absorbed into your bloodstream and processed by the liver.

Because you place these drops directly into your ear, very little of the medicine reaches your blood. So a quercetin supplement is very unlikely to meaningfully change how these ear drops work or cause more side effects. This concern is mostly theoretical for swallowed drugs anyway. Still, if you ever take oral ciprofloxacin or have other questions, check with your pharmacist.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Wu LX, Guo CX, Chen WQ, et al. Inhibition of the organic anion-transporting polypeptide 1B1 by quercetin: an in vitro and in vivo assessment. Br J Clin Pharmacol 2012;73(5):750-7.

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

Quercetin Also Interacts With Other Medications

Quercetin has 1,168 moderate known drug interactions in our database — the Ciprofloxacin, Hydrocortisone one above is among them. If you take anything else, check it against the full list below.

Moderate 1,168 No known interaction 1,662 (incl. Ciprofloxacin, Hydrocortisone)
Taking anything else?

Check Another of Your Medications Against Quercetin

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

Everything else you take

See Every Supplement That Interacts With Ciprofloxacin, Hydrocortisone

This page covers Quercetin only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ciprofloxacin, Hydrocortisone page lists 20 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Apple (major), Grapefruit (major), Sweet Orange (major), African Wild Potato (moderate) and Banaba (moderate).

By severity: 3 major · 11 moderate · 6 minor.

From our pharmacist’s overview on the Ciprofloxacin, Hydrocortisone page

“A glass of juice at breakfast is the last thing most people would question while treating an ear infection, yet all three major-rated interactions for Cipro HC Otic (ciprofloxacin and hydrocortisone) involve exactly that: apple, grapefruit, and sweet orange juice, each shown in human studies to block a gut transporter called OATP and c…”

Reviewed by 2 · Jul 18, 2026

Open the Ciprofloxacin, Hydrocortisone interaction page

One more smart check

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

We hold 4,589 real supplement products containing Quercetin, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Quercetin. Your product may carry other ingredients that interact with Ciprofloxacin, Hydrocortisone too, on top of Quercetin — 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 Quercetin and Ciprofloxacin, Hydrocortisone 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 Quercetin
Top 5%

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

29 days ago today
Medication Ciprofloxacin, Hydrocortisone
Steady interest

#2,461 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 Quercetin

What is Quercetin?

Quercetin
  • Seasonal allergies
  • Antioxidant support
  • Heart and blood pressure health
  • Anti-inflammatory support
  • Immune support
  • Exercise recovery

Quercetin is a plant flavonoid with antioxidant and anti-inflammatory properties found in many common foods and sold as a supplement. While early research is interesting for allergies, blood pressure, and inflammation, strong human evidence is limited for most uses. It is generally well tolerated in food amounts, but talk to your pharmacist or doctor before taking high-dose supplements.

Read the full Quercetin monograph & all interactions
Keep checking

Other Drugs & Quercetin

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

0Major
1,168Moderate
0Minor
1,661No known interaction
1,168 Moderate 1,661 No interaction
Moderate

1,168 interactions

Showing 60 of 1,168 moderate interactions — see all 1,168 on the Quercetin page.

No interaction 1,661 drugs checked — show the list

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

Showing the 60 most looked-up of 1,661 medications checked with no known interaction — see the full Quercetin list.

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

Can you take Quercetin with Ciprofloxacin, Hydrocortisone?
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 Quercetin and Ciprofloxacin, Hydrocortisone?
Ciprofloxacin, Hydrocortisone belongs to more than one drug category, and Quercetin 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 Quercetin and Ciprofloxacin, Hydrocortisone 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.