Drug & supplement interaction

Caffeine + Terbinafine

Terbinafine brand name: Lamisil.

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

Caffeine has a minor interaction with Terbinafine. Theoretically, terbinafine might increase the levels and adverse effects of caffeine.

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

Caffeine and Terbinafine

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

Minor

TERBINAFINE (Lamisil)

Theoretically, terbinafine might increase the levels and adverse effects of caffeine.
Terbinafine decreases the clearance of intravenous caffeine by 19%.
Severity Minor 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

Here's the deal with these two: terbinafine slows down how fast your body clears caffeine. In one study, it cut caffeine clearance by about 19%, so the caffeine you drink can hang around a bit longer than usual. It's the terbinafine doing the affecting here, and caffeine is the one that builds up, not the other way around.

What might you actually notice? Slightly more of the usual caffeine feelings, like jitteriness, a faster heartbeat, or trouble sleeping. This is rated a minor interaction and is largely theoretical, so most people won't have a problem. If you feel wired, simply easing back on coffee, tea, or energy drinks usually does the trick. As always, run any concerns by your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Wahllander A, Paumgartner G. Effect of ketoconazole and terbinafine on the pharmacokinetics of caffeine in healthy volunteers. Eur J Clin Pharmacol 1989;37:279-83. PubMed

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

Caffeine Also Interacts With Other Medications

Caffeine has 8 major, 483 moderate, 163 minor known drug interactions in our database — the Terbinafine one above is one of them. If you take anything else, check it against the full list below.

Major 8 Moderate 483 Minor 163 No known interaction 2,176 (incl. Terbinafine)
Taking anything else?

Check Another of Your Medications Against Caffeine

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

From our Q&A

Questions About Caffeine or Terbinafine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Caffeine or Terbinafine, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Terbinafine

This page covers Caffeine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Terbinafine page lists 72 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Siberian Cocklebur (major), Wine (major) and Ashwagandha (moderate).

By severity: 4 major · 45 moderate · 23 minor.

From our pharmacist’s overview on the Terbinafine page

“Liver strain is the risk that dominates this list. Terbinafine (Lamisil), the antifungal most people take for months to clear a nail infection, can injure the liver in rare cases on its own, and 38 of the 72 supplements catalogued here carry liver risks that could stack on top of that.”

Reviewed by 2 · Jul 18, 2026

Open the Terbinafine interaction page

One more smart check

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

We hold 6,775 real supplement products containing Caffeine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Caffeine. Your product may carry other ingredients that interact with Terbinafine too, on top of Caffeine — 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 Caffeine and Terbinafine 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 Caffeine
Top 5%

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

29 days ago today
Medication Terbinafine
Top 25%

#499 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 Caffeine

What is Caffeine?

  • Mental alertness and reducing fatigue
  • Improving athletic performance
  • Headache and migraine relief
  • Boosting focus and concentration
  • Weight loss aid

Caffeine is a natural stimulant found in coffee, tea, and many other plants and products. In moderate amounts it can boost alertness and reduce tiredness for most healthy adults, but too much can cause jitteriness, a racing heart, and sleep problems. Pregnant women and people with heart conditions or anxiety should be especially careful and check with a doctor or pharmacist.

Read the full Caffeine monograph & all interactions
Medication

About Terbinafine

What Is Terbinafine Used For?

Brand name: Lamisil

Terbinafine tablets are used to treat onychomycosis — a fungal infection of the fingernails or toenails caused by dermatophytes (a type of fungus). Before starting the tablets, a doctor will confirm the diagnosis with a nail test.

Topical terbinafine products — creams and sprays — treat athlete's foot (tinea pedis), jock itch (tinea cruris), and ringworm (tinea corporis) on the skin. They also relieve the itching, burning, cracking, and scaling that come with these infections. Lamisil AT Spray is indicated for athlete's foot between the toes specifically; its effectiveness on the bottom or sides of the foot is unknown.

See full Terbinafine drug information
Keep checking

Other Drugs & Caffeine

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

8Major
483Moderate
163Minor
2,175No known interaction
8 Major 483 Moderate 163 Minor 2,175 No interaction
Major

8 interactions

Moderate

483 interactions

Showing 60 of 483 moderate interactions — see all 483 on the Caffeine page.

Minor

163 interactions

Showing 60 of 163 minor interactions — see all 163 on the Caffeine page.

No interaction 2,175 drugs checked — show the list

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

Showing the 60 most looked-up of 2,175 medications checked with no known interaction — see the full Caffeine list.

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

Can you take Caffeine with Terbinafine?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Caffeine and Terbinafine interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Terbinafine and Caffeine?

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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.