When Can I Drink Alcohol After Taking Penicillin?

In our latest question and answer, the pharmacist discusses alcohol consumption while taking the antibiotic penicillin.

3 min read Updated Jun 2026 Read by 16,308 people
When Can I Drink Alcohol After Taking Penicillin?
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Taylor asked

When can I drink alcohol after taking penicillin?

Dec 07, 2022
The quick answer
  • While there is no direct drug interaction between penicillin and alcohol, drinking alcohol while recovering from an infection can worsen side effects like nausea, diarrhea, and upset stomach and may decrease your immune function. For most healthy individuals, penicillin clears from the body within 10-12 hours, so waiting at least 12 hours after your last dose before drinking alcohol is recommended. If you have kidney or liver impairment, it is prudent to wait longer since penicillin takes several days to clear from your body in those cases.
A quick summary of Dr. Brian Staiger, PharmD's full answer below, condensed by AI from that answer only (not from any outside source). The pharmacist's answer is the source of record.

Answer

Alcohol consumption while taking medication, especially antibiotics, often brings concerns from patients and healthcare professionals alike. While there is no specific drug interaction between penicillin and alcohol, it generally is not recommended to drink alcohol while recovering from an infection for a number of reasons.

Alcohol can decrease immune function and worsen antibiotic side effects such as:

  • Nausea
  • Diarrhea
  • Upset stomach

While recovering from an infection, it is important to stay well-hydrated and get plenty of rest. 

Timing Of Alcohol Consumption After Taking Penicillin

How long penicillin lasts in the body varies considerably per individual.

According to the prescribing information for penicillin, the half-life (i.e. time it takes for 50% of a drug to be metabolized) is around 45-75 minutes in healthy individuals. The half-life increases greatly in those with kidney or liver impairment and has been reported to be over 30 hours in patients with severe kidney impairment.

Based on the half-life statistics, penicillin will be cleared from the body within 10-12 hours for most healthy individuals. In those with kidney or liver impairment, it may take several days to be cleared.

If you wish to completely avoid alcohol while penicillin is present in your body, waiting at least 12 hours after your last dose of penicillin to drink alcohol is recommended and will reduce the risk of worsened side effects. If you have kidney or liver impairment, it would be prudent to wait longer.

Information About Alcohol

Alcohol is primarily metabolized via alcohol dehydrogenase, aldehyde dehydrogenase, cytochrome P450 (CYP2E1), and catalase. The byproducts of alcohol include acetaldehyde and acetate which contribute to many of the negative effects.

Genetic variation of these enzymes causes varying degrees of alcohol metabolism—which is why everyone tolerates alcohol differently.

This metabolism takes place mostly in the liver. CYP enzymes play a particularly important role in drug metabolism and drug interactions occur via the inhibition or induction of these enzymes. Alcohol does impact CYP enzymes, especially CYP2E1.

Information About Penicillin

Penicillin is a beta-lactam antibiotic that is used for the treatment of respiratory, skin, cardiac, and ear infections, among others. Any antibiotics in the penicillin class should be avoided in patients with a true penicillin allergy.

Reported allergies to penicillins are thought to be higher than the rate of true penicillin allergies. It is important to let your doctor and pharmacist know about your allergies or other adverse reactions before taking any medication. 

Only about 25% of penicillin is absorbed in the GI tract and is excreted primarily through the kidney. It is not extensively metabolized by CYP enzymes so will not impact the metabolism of alcohol. Penicillin can cause rash, nausea, vomiting, and diarrhea.

Final Words

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References & sources
  1. Overview: How Is Alcohol Metabolized by the Body — NIAAA
  2. Penicillin Monograph — AccessFDA
  3. Penicillin Monograph — PubChem
Glossary — Terms in This Answer
Half-life
The amount of time it takes for half of a drug dose to be broken down and removed from your body.
Metabolized
The process by which your body breaks down a substance like a drug or alcohol into different chemicals.
Kidney impairment
A condition where the kidneys are not working properly and cannot filter waste and drugs from the blood as effectively.
Liver impairment
A condition where the liver is not working properly and cannot break down drugs and other substances as effectively.
Alcohol dehydrogenase
An enzyme in your liver that helps break down alcohol in your body.
Cytochrome P450
A group of enzymes in your liver that break down many drugs and other substances, and also affect how alcohol is processed.
Beta-lactam antibiotic
A type of antibiotic that works by damaging bacterial cell walls, with penicillin being a common example.
GI tract
Your gastrointestinal system, including your stomach and intestines, where food and medications are absorbed into your body.
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Dr. Brian Staiger, PharmD
About the pharmacist

Dr. Brian Staiger, PharmD

Clinical Pharmacy

Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified

Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...

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