Drug & supplement interaction

Beer + Phenytoin

Phenytoin brand names: Dilantin Kapseals, Dilantin, Di-Phen, Dilantin Infatabs, Phenytek, and others.

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

Phenytoin falls into 3 drug categories that Beer can interact with; the most serious is rated major. Concomitant use may increase sedative and other adverse effects.

Read the full interaction report
SeverityMajor
LikelihoodLikely
Interactions3
EvidenceC
What do Severity, Likelihood & Evidence mean?
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Interaction report

Beer and Phenytoin

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Beer interacts with whole categories of medication. Phenytoin falls into 3 of those categories, so it can interact with Beer in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Major).

Major

CNS DEPRESSANTS

1 of 3

Why this applies to Phenytoin

Phenytoin falls under CNS DEPRESSANTS — the group Beer interacts with.

Concomitant use may increase sedative and other adverse effects.
Concomitant use of alcohol with CNS depressants can increase sedative and other adverse effects, potentially through inhibition of the metabolism of certain CNS depressants.
Severity Major Likelihood Likely Evidence C

Well-controlled human studies have demonstrated the likely existence of this interaction.

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

Here's the thing about mixing beer with phenytoin (Dilantin). Both alcohol and phenytoin can slow down your brain, so having them together can stack up that effect. You may feel extra drowsy, dizzy, unsteady on your feet, or have trouble concentrating. That can also raise your risk of falls or accidents.

Phenytoin is a tricky medication because it has a narrow safety window, meaning small changes in its blood level can tip you toward side effects or, on the other end, poor seizure control. Occasional alcohol affects it differently than regular heavy drinking, and heavy use over time can actually lower how well phenytoin works to prevent seizures. Please talk with your pharmacist or doctor before drinking beer while on this medicine.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Fraser AG. Pharmacokinetic interactions between alcohol and other drugs. Clin Pharmacokinet 1997;33:79-90. PubMed
Major

HEPATOTOXIC DRUGS

2 of 3

Phenytoin also falls under HEPATOTOXIC DRUGS.

Concomitant use of alcohol with hepatotoxic drugs may increase the risk of hepatotoxicity.
Concomitant use of excessive amounts of alcohol with potentially hepatotoxic drugs can increase the risk of liver damage.
Severity Major 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 about mixing beer with phenytoin (Dilantin): both are processed by your liver, and both can stress it. Drinking heavily on a regular basis while taking phenytoin can raise your odds of liver damage, with warning signs like yellowing skin or eyes, dark urine, belly pain, nausea, or unusual tiredness.

There's another wrinkle worth knowing. Phenytoin has a narrow safety window, so small shifts in its blood level matter. Heavy or binge drinking can push your level around and make side effects like dizziness, slurred speech, or poor balance worse, while steady long-term drinking may lower it and reduce seizure control. An occasional drink is a different story, but please check with your pharmacist or doctor before mixing the two.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Fraser AG. Pharmacokinetic interactions between alcohol and other drugs. Clin Pharmacokinet 1997;33:79-90. PubMed
  2. Thummel, K. E., Slattery, J. T., Ro, H., Chien, J. Y., Nelson, S. D., Lown, K. E., and Watkins, P. B. Ethanol and production of the hepatotoxic metabolite of acetaminophen in healthy adults. Clin Pharmacol Ther 2000;67(6):591-599. PubMed
Major

PHENYTOIN (Dilantin)

3 of 3
Concomitant use may decrease the effectiveness of phenytoin.
Chronic, heavy alcohol use can induce the metabolism of phenytoin, reducing therapeutic effectiveness.
Severity Major Likelihood Probable Evidence C

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 with phenytoin and beer: regular, heavy drinking over time can rev up the liver enzymes that break phenytoin down. When that happens, your body clears the medicine faster, so the level in your blood can drop. Lower levels mean less seizure protection, and that raises the risk of a breakthrough seizure even if you're taking every dose exactly as prescribed.

Phenytoin is a tricky drug because the right and wrong amount are close together, so changes really do matter. The big concern is chronic, heavy alcohol use, not an occasional single beer. Still, since this is a serious medicine, talk with your doctor or pharmacist about your drinking before changing anything. They can check a blood level if needed.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Fraser AG. Pharmacokinetic interactions between alcohol and other drugs. Clin Pharmacokinet 1997;33:79-90. 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

Beer Also Interacts With Other Medications

Beer has 653 major, 272 moderate known drug interactions in our database — the Phenytoin one above is among them. If you take anything else, check it against the full list below.

Major 653 Moderate 272 No known interaction 1,905 (incl. Phenytoin)
Taking anything else?

Check Another of Your Medications Against Beer

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

From our Q&A

Questions About Beer or Phenytoin

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Beer or Phenytoin, 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 Phenytoin

This page covers Beer only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Phenytoin page lists 224 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Gamma-hydroxybutyrate (ghb) (major), Kava (major) and L-tryptophan (major).

By severity: 9 major · 187 moderate · 28 minor.

From our pharmacist’s overview on the Phenytoin page

“Phenytoin (Dilantin) is a seizure medicine with a narrow therapeutic index, meaning small changes in its blood level can bring seizures back or tip over into toxicity, so I treat its supplement list with real seriousness. The biggest group, 78 ingredients, piles on sedation, and alcohol, kava, and GHB all rate major for exactly that re…”

Reviewed by 2 · Jul 18, 2026

Open the Phenytoin interaction page

How much people look this up

Where Beer and Phenytoin 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 Beer
Top 25%

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

29 days ago today
Medication Phenytoin
Steady interest

#1,709 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 Beer

What is Beer?

Beer
  • Social and recreational drinking
  • Relaxation
  • Heart health (popular belief)
  • Bone health (popular belief)
  • Source of antioxidants and B vitamins

Beer is an alcoholic beverage that contains some minerals, B vitamins, and plant compounds from hops and grain, but it is not a health supplement. Any possible benefits come only from light-to-moderate intake, and they are easily outweighed by the well-known harms of alcohol. The safest amount of alcohol for health is none, and beer should be avoided in pregnancy and breastfeeding.

Read the full Beer monograph & all interactions
Medication

About Phenytoin

What Is Phenytoin Used For?

Brand names: Dilantin Kapseals, Dilantin, Di-Phen, Dilantin Infatabs, Phenytek, Dilantin injection

Phenytoin is used to treat and prevent seizures. The specific types covered depend on the formulation. Oral extended-release capsules (including Phenytek), chewable tablets (including Dilantin Infatabs and Phenytoin Infatabs), and oral suspension (including Dilantin-125) are used for tonic-clonic (grand mal) and psychomotor (temporal lobe) seizures; most oral forms also cover prevention and treatment of seizures occurring during or after neurosurgery. Chewable tablets and some capsule formulations also cover complex partial seizures.

Parenteral (injectable) phenytoin sodium is used for generalized tonic-clonic status epilepticus (a prolonged, life-threatening seizure emergency) and for prevention and treatment of seizures during neurosurgery. The IV form can also substitute short-term for oral phenytoin when a patient cannot take it by mouth.

See full Phenytoin drug information
Keep checking

Other Drugs & Beer

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

653Major
272Moderate
0Minor
1,904No known interaction
653 Major 272 Moderate 1,904 No interaction
Major

653 interactions

Showing 60 of 653 major interactions — see all 653 on the Beer page.

Moderate

272 interactions

Showing 60 of 272 moderate interactions — see all 272 on the Beer page.

No interaction 1,904 drugs checked — show the list

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

Showing the 60 most looked-up of 1,904 medications checked with no known interaction — see the full Beer list.

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

Can you take Beer with Phenytoin?
This is rated a major interaction, so the combination is best avoided unless your doctor or pharmacist has specifically told you otherwise. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 3 interactions listed for Beer and Phenytoin?
Phenytoin belongs to more than one drug category, and Beer 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 Beer and Phenytoin interaction?
We rate it Major. This is a clinically significant combination that is generally best avoided, or used only under the direct supervision of your physician or pharmacist.

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

Still Have a Question About Phenytoin and Beer?

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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.