Drug & supplement interaction

Black Tea + Clinafloxacin

Clinafloxacin brand name: Clinafloxacin.

Moderate Interaction
The bottom line Moderate

Clinafloxacin falls into 2 drug categories that Black Tea can interact with; the most serious is rated moderate. Theoretically, black tea might reduce the absorption of organic anion-transporting polypeptide (OATP) substrates.

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

Black Tea and Clinafloxacin

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

Why Are There 2 Interactions?

Black Tea interacts with whole categories of medication. Clinafloxacin falls into 2 of those categories, so it can interact with Black Tea 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-TRANSPORTING POLYPEPTIDE SUBSTRATES (OATP)

1 of 2

Why this applies to Clinafloxacin

Clinafloxacin falls under ORGANIC ANION-TRANSPORTING POLYPEPTIDE SUBSTRATES (OATP) — the group Black Tea interacts with.

Theoretically, black tea might reduce the absorption of organic anion-transporting polypeptide (OATP) substrates.
In vitro, black tea extract inhibits organic anion-transporting polypeptide (OATP)2B1. OATP2B1 is expressed in the small intestine and liver and is responsible for the uptake of drugs and other compounds. In an animal model, black tea extract was found to inhibit the absorption of rosuvastatin, a substrate of OATP2B1. However, 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 if you're sipping black tea while taking the antibiotic clinafloxacin. Black tea has plant compounds that, in lab dishes, can block a gut transporter called OATP2B1 that helps pull certain drugs from your intestine into your blood. The worry is that this could lower how much of the medicine actually gets absorbed, which for an antibiotic could mean it doesn't reach the levels needed to fully knock out an infection. Clinafloxacin is an active drug, not a prodrug, so less absorption simply means a weaker effect, not stronger.

I want to be honest, though: this is theoretical and only seen in lab and animal studies (it was shown with a cholesterol drug, not clinafloxacin), never confirmed in people. To be safe, just space your tea a couple hours from your dose and check with your pharmacist.

References
  1. Kondo A, Narumi K, Okuhara K, et al. Black tea extract and theaflavin derivatives affect the pharmacokinetics of rosuvastatin by modulating organic anion transporting polypeptide (OATP) 2B1 activity. Biopharm Drug Dispos. 2019;40(8):302-306. PubMed
Moderate

QUINOLONE ANTIBIOTICS

2 of 2

Clinafloxacin also falls under QUINOLONE ANTIBIOTICS.

Theoretically, quinolone antibiotics might increase the levels and adverse effects of caffeine.
Black tea contains caffeine. Concomitant use of caffeine and quinolones can decrease caffeine clearance and increase effects and risk of adverse effects.
Severity Moderate Likelihood Probable Evidence B

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 thing to know about pairing your black tea with clinafloxacin: this antibiotic belongs to the quinolone family, and quinolones can slow down how fast your body clears caffeine. So the caffeine from your tea hangs around longer than usual. The result isn't that the antibiotic changes, it's that the caffeine packs more of a punch.

In practice, that can mean feeling more jittery, a racing or pounding heart, trouble sleeping, or a mild bump in blood pressure. This is considered probable but the effect is generally modest, especially if you're a moderate tea drinker. If you notice you're wired or restless while on this antibiotic, cutting back on caffeine usually helps. Check with your pharmacist or doctor before making any changes.

References
  1. Harder S, Fuhr U, Staib AH, Wolff T. Ciprofloxacin-caffeine: a drug interaction established using in vivo and in vitro investigations. Am J Med 1989;87:89S-91S. PubMed
  2. Carbo M, Segura J, De la Torre R, et al. Effect of quinolones on caffeine disposition. Clin Pharmacol Ther 1989;45:234-40. PubMed
  3. Healy DP, Polk RE, Kanawati L, et al. Interaction between oral ciprofloxacin and caffeine in normal volunteers. Antimicrob Agents Chemother 1989;33:474-8. PubMed
  4. Stille, W., Harder, S., Mieke, S., Beer, C., Shah, P. M., Frech, K., and Staib, A. H. Decrease of caffeine elimination in man during co-administration of 4-quinolones. J.Antimicrob.Chemother. 1987;20(5):729-734. PubMed
  5. Harder S, Staib AH, Beer C, et al. 4-quinolones inhibit biotransformation of caffeine. Eur J Clin Pharmacol 1988;35:651-6. PubMed
  6. Zhang LL, Zhang JR, Guo K, et al. Effects of fluoroquinolones on CYP4501A and 3A in male broilers. Res Vet Sci 2011;90:99-105. PubMed
  7. Cesana M, Broccali G, Imbimbo BP, Crema A. Effect of single doses of rufloxacin on the disposition of theophylline and caffeine after single administration. Int J Clin Pharmacol Ther Toxicol 1991:29:133-8.

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

Black Tea Also Interacts With Other Medications

Black Tea has 8 major, 571 moderate, 114 minor known drug interactions in our database — the Clinafloxacin one above is among them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Black Tea

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

Everything else you take

See Every Supplement That Interacts With Clinafloxacin

This page covers Black Tea only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Clinafloxacin page lists 87 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Apple (major), Grapefruit (major), Sweet Orange (major) and Bacillus Coagulans (moderate).

By severity: 4 major · 62 moderate · 21 minor.

From our pharmacist’s overview on the Clinafloxacin page

“If you have been prescribed clinafloxacin, a quinolone antibiotic, start with the four interactions rated major, because they all do the same thing: apple, grapefruit, and orange juice, along with activated charcoal, can sharply cut how much of the drug you absorb, and an antibiotic that never reaches your bloodstream cannot clear the…”

Reviewed by 2 · Jul 18, 2026

Open the Clinafloxacin interaction page

One more smart check

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

We hold 271 real supplement products containing Black Tea, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Black Tea. Your product may carry other ingredients that interact with Clinafloxacin too, on top of Black Tea — 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 Black Tea and Clinafloxacin 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 Black Tea
Top 25%

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

29 days ago today
Medication Clinafloxacin
Top half

#787 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 Black Tea

What is Black Tea?

  • Mental alertness and energy
  • Heart health support
  • Blood pressure and cholesterol
  • Digestive complaints
  • Weight management
  • Antioxidant support

Black tea is a popular caffeinated drink made from the fully oxidized leaves of the Camellia sinensis plant, and it contains caffeine and antioxidant plant compounds. Moderate tea drinking is generally safe for most adults and may modestly support heart health and alertness, but it is not a proven treatment for any disease. If you are pregnant, breastfeeding, sensitive to caffeine, or taking medicines, talk to your pharmacist or doctor.

Read the full Black Tea monograph & all interactions
Keep checking

Other Drugs & Black Tea

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

8Major
571Moderate
114Minor
2,136No known interaction
Major

8 interactions

Moderate

571 interactions

Showing 60 of 571 moderate interactions — see all 571 on the Black Tea page.

Minor

114 interactions

Showing 60 of 114 minor interactions — see all 114 on the Black Tea page.

No interaction 2,136 drugs checked — show the list
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

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Pharmacist Counseling Corner

Taking Black Tea and Clinafloxacin Together: Common Questions

Can you take Black Tea with Clinafloxacin?
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 Black Tea and Clinafloxacin?
Clinafloxacin belongs to more than one drug category, and Black Tea 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 Black Tea and Clinafloxacin 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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