Many people believe that mixing alcohol and antibiotics is not safe. Is it dangerous? What are the risks of drinking alcohol while taking antibiotics?

Antibiotics are drugs that target bacteria to treat and prevent infections. There are many types of oral antibiotic.

Not all antibiotics interact with alcohol, and doctors give different recommendations about alcohol depending on the type of antibiotic.

In this article, we discuss the risks of mixing antibiotics and alcohol. We also explore the effects of alcohol on the immune system.

Is it safe to mix alcohol and antibiotics?

man holding glass of whiskey
A person may experience digestive problems when they drink alcohol while taking antibiotics.

Not all antibiotics interact with alcohol. Depending on the type of antibiotic someone is taking, doctors may recommend limiting or avoiding alcohol intake.

Alcohol interacts directly with some antibiotics and can cause dangerous side effects or make them less effective at removing bacteria.

When the body breaks down alcohol, it also produces acetaldehyde, which can cause nausea. Many people experience stomach or digestive side effects when taking antibiotics.

Drinking alcohol while taking antibiotics may increase this feeling of nausea due to the combined side effects.

Although nausea is a common side effect of both antibiotics and alcohol, not all people will experience this when using both at the same time.

In the following sections, we discuss the effects of alcohol on specific classes of antibiotics.

The effects of mixing alcohol and antibiotics

The table below summarizes the effects of drinking while taking antibiotics.

Antibiotic class Antibiotic Should I avoid or limit alcohol? Effect of mixing alcohol and antibiotics
Tetracyclines Doxycycline Avoid alcohol during treatment. reduced effect of antibiotic
Tetracyclines Minocycline Avoid alcohol during treatment. liver disease
Oxazolidinones Linezolid Avoid alcohol during treatment. agitation
unusual sweating
rapid heartbeat
fever
altered mental status
rapid breathing
vomiting
abnormal heart rhythm
elevated blood pressure
seizures
coma
cardiorespiratory depression
muscle rigidity
muscle spasms
Sulfonamides Sulfamethoxazole and trimethoprim Limit alcohol consumption. folic acid deficiency
Fluoroquinolones Ciprofloxacin
Levofloxacin
Moxifloxacin
Limit alcohol consumption. disturbances in attention
disorientation
agitation
nervousness
memory loss
confusion
Nitroimidazole Metronidazole Avoid alcohol during treatment.
Avoid for 72 hours after the last dose.
abdominal cramping
nausea
vomiting
headaches
facial flushing

Tetracyclines

The tetracycline class of antibiotics includes doxycycline and minocycline. This class can treat a wide range of bacterial infections.

People should not drink alcohol while taking doxycycline because this may reduce the effects of the antibiotic. Doxycycline may interact with alcohol. Alcohol speeds up the body’s elimination of the doxycycline and therefore makes it less effective.

Liver toxicity is a rare side effect of taking minocycline. Since alcohol can also have negative effects on the liver, people should avoid mixing alcohol with minocycline.

Oxazolidinones

Linezolid belongs to the oxazolidinone class of antibiotics. Doctors use oxazolidinones to treat abdominal, skin, lung, and urinary tract infections.

As well as its antibacterial effect, linezolid reduces the action of enzymes called monoamine oxidase-A and monoamine oxidase-B. Monoamine oxidases break down tyramine. Tyramine is a substance present in tap beers and red wine, among other products.

When people drink tap beers and red wine with linezolid, the amount of tyramine in the blood may rise.

People may experience the following mild, moderate, or severe side effects after drinking these types of alcohol while taking oxazolidinones:

Mild Moderate Severe
agitation
unusual sweating
rapid heartbeat
fever
altered mental status
rapid breathing
vomiting
abnormal heart rhythm
elevated blood pressure
seizures
coma
cardiorespiratory depression
muscle rigidity
muscle spasms

This is not an interaction with alcohol but with a component present in tap beers and red wine.

People should avoid red wine and tap beers when taking linezolid. They should also avoid other foods that contain tyramine, such as strong cheeses and smoked meats.

Sulfonamides

Physicians prescribe sulfonamide antibiotics to treat urinary, respiratory, and abdominal infections. Sulfonamide antibiotics include the combination drug sulfamethoxazole and trimethoprim, which healthcare professionals also call Septra.

Sulfamethoxazole and trimethoprim affect the metabolism of folic acid in bacteria. Trimethoprim can, in rare cases, also affect the metabolism of folic acid in human cells.

People deficient in folic acid may be at risk of further reducing their folic acid levels while taking sulfamethoxazole and trimethoprim. People who drink alcohol regularly may have lower levels of folic acid and should use sulfamethoxazole and trimethoprim with caution.

Although an occasional drink is safe with sulfonamides, healthcare providers should exercise caution when prescribing sulfamethoxazole and trimethoprim to people who drink often.

Fluoroquinolones

In 2018, the Food and Drug Administration (FDA) published updated safety warnings on all fluoroquinolone antibiotics.

The labels of all fluoroquinolones now highlight the possible mental health side effects of the drug. These side effects may include:

  • disturbances in attention
  • disorientation
  • agitation
  • nervousness
  • memory loss
  • confusion

Mixing alcohol with fluoroquinolone antibiotics may increase these mental health side effects.

In rare cases, people may experience seizures with fluoroquinolone treatment. People with a history of seizures are most at risk.

Since alcohol lowers the seizure threshold, doctors advise people with a history of seizures to avoid mixing alcohol and fluoroquinolones.

An occasional drink with fluoroquinolone can be safe, but drinking regularly may cause central nervous system side effects.

Nitroimidazoles

Metronidazole is a nitroimidazole antibiotic that doctors prescribe to treat abdominal infections, sexually transmitted infections, and other anaerobic bacteria-related infections.

Metronidazole affects the function of a key enzyme that helps the body digest alcohol. When metronidazole inhibits the enzyme aldehyde dehydrogenase, the levels of acetaldehyde accumulate in the blood. This causes the toxic effects of alcohol.

Mixing alcohol with metronidazole may cause:

  • abdominal cramping
  • nausea
  • vomiting
  • headaches
  • facial flushing

People should avoid drinking alcohol during treatment and for up to 3 days after the last dose.

Despite this interaction, not everyone will experience these reactions when drinking while taking metronidazole. An individual risk is possible. Still, people should avoid drinking alcohol while taking metronidazole.

The effect of alcohol on the immune system

happy senior women drinking wine
Some scientists have associated moderate alcohol consumption with a lower risk of infection.

Some research suggests that moderate alcohol consumption is linked to a lower risk of infection. The Centers for Disease Control and Protection (CDC) define moderate alcohol consumption as:

  • one drink per day for women
  • two drinks per day for men

The CDC define binge drinking as consuming four drinks for women and five drinks for men on a single occasion. Heavy drinking is eight or more drinks for women and 15 drinks or more for men per week.

Scientists have linked heavy and binge drinking with an impaired immune system. People with an impaired immune system have a higher risk of infection.

Summary

Alcohol interferes with some antibiotics in different ways. The effectiveness or side effects may be altered when people drink while taking certain antibiotics.

People should be aware that the stomach- and digestion-related side effects of any antibiotic may be more intense when mixed with alcohol.