Drug & supplement interaction

Coffee + Nalidixic Acid

Nalidixic Acid brand name: NegGram.

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

Coffee has a moderate interaction with Nalidixic Acid. Theoretically, quinolone antibiotics might increase the levels and adverse effects of caffeine.

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

Coffee and Nalidixic Acid

Here is the interaction we found between these two, with the evidence behind it.

Moderate

QUINOLONE ANTIBIOTICS

Why this applies to Nalidixic Acid

Nalidixic Acid falls under QUINOLONE ANTIBIOTICS — the group Coffee interacts with.

Theoretically, quinolone antibiotics might increase the levels and adverse effects of caffeine.
Coffee 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 if you enjoy your coffee while taking nalidixic acid: this antibiotic can slow down how your body clears caffeine. Nalidixic acid itself isn't changed, but the caffeine in your cup may hang around longer and pile up. So that same morning coffee can hit harder than usual.

What might you notice? More of the usual caffeine effects: feeling jittery or restless, a racing or pounding heartbeat, trouble sleeping, or an upset stomach. You don't have to give up coffee, but it may be wise to cut back a bit while you're on this medicine, especially if you're sensitive to caffeine. If the buzz feels stronger than normal, check in with your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
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

Coffee Also Interacts With Other Medications

Coffee has 8 major, 466 moderate, 116 minor known drug interactions in our database — the Nalidixic Acid one above is one of them. If you take anything else, check it against the full list below.

Major 8 Moderate 466 Minor 116 No known interaction 2,240 (incl. Nalidixic Acid)
Taking anything else?

Check Another of Your Medications Against Coffee

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

Everything else you take

See Every Supplement That Interacts With Nalidixic Acid

This page covers Coffee only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Nalidixic Acid page lists 146 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Apple (major), Asarabacca (major), Beer (major) and Grapefruit (major).

By severity: 8 major · 118 moderate · 20 minor.

Open the Nalidixic Acid interaction page

One more smart check

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

We hold 716 real supplement products containing Coffee, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Coffee. Your product may carry other ingredients that interact with Nalidixic Acid too, on top of Coffee — 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 Coffee and Nalidixic Acid 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 Coffee
Top 5%

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

29 days ago today
Medication Nalidixic Acid
Top half

#1,069 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 Coffee

What is Coffee?

  • Alertness and reducing fatigue
  • Mental focus and concentration
  • Athletic performance
  • Headache relief
  • Weight management

Coffee is a widely consumed beverage made from roasted coffee beans, valued mainly for its caffeine, which boosts alertness and energy. For most healthy adults, moderate coffee intake is generally safe and may have some health benefits, but too much can cause jitteriness, poor sleep, and a faster heartbeat. People who are pregnant, breastfeeding, or sensitive to caffeine should limit their intake and check with a doctor or pharmacist.

Read the full Coffee monograph & all interactions
Keep checking

Other Drugs & Coffee

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

8Major
466Moderate
116Minor
2,239No known interaction
8 Major 466 Moderate 116 Minor 2,239 No interaction
Major

8 interactions

Moderate

466 interactions

Showing 60 of 466 moderate interactions — see all 466 on the Coffee page.

Minor

116 interactions

Showing 60 of 116 minor interactions — see all 116 on the Coffee page.

No interaction 2,239 drugs checked — show the list

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

Showing the 60 most looked-up of 2,239 medications checked with no known interaction — see the full Coffee list.

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

Can you take Coffee with Nalidixic Acid?
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.
How serious is the Coffee and Nalidixic Acid 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 Nalidixic Acid and Coffee?

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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.