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What should I do if I’ve taken Flagyl and alcohol together?

Flagyl (metronidazole) is an antibiotic that is used to treat certain bacterial and parasitic infections. When taken with alcohol, Flagyl can cause severe nausea, vomiting, abdominal cramps, headaches, and flushing. This is caused by a reaction between the alcohol and Flagyl in the body. While the effects usually only last for 30 minutes to several hours, it is still best to avoid consuming any alcohol while taking Flagyl and for at least 3 days after finishing the medication.

What is Flagyl?

Flagyl (generic name metronidazole) is an antibiotic medication that is used to treat certain bacterial and parasitic infections in different parts of the body. Some examples of infections that Flagyl is commonly prescribed for include:

  • Bacterial vaginosis
  • Pelvic inflammatory disease
  • Endocarditis
  • Infections of the stomach and intestines
  • Lung abscesses
  • Gum infections
  • Diabetic foot infections
  • Certain parasitic infections like Trichomoniasis and Giardiasis

Flagyl works by stopping the growth of bacteria and parasites. The medication comes in tablet, capsule, and intravenous forms. It is available both over the counter and by prescription depending on the dosage and formulation.

Why You Should Not Mix Flagyl and Alcohol

Drinking alcohol while taking Flagyl can cause severe side effects that may be dangerous. This is because alcohol and Flagyl both get broken down by enzymes in your liver and interact. Possible side effects that can occur when the two are mixed include:

  • Nausea
  • Vomiting
  • Abdominal cramps
  • Headaches
  • Flushing of the face and body
  • Rapid heart rate
  • Shortness of breath
  • Low blood pressure

These unpleasant effects can begin within 30 minutes of drinking alcohol with Flagyl in your system. In most cases, the severity of symptoms peaks around 1-2 hours after ingestion and lasts for about 3 hours. However, some people may continue experiencing side effects for up to several days after the fact.

The reaction appears to be the result of an accumulation of acetaldehyde, a byproduct broken down from alcohol metabolism. Flagyl seems to inhibit acetaldehyde breakdown, causing it to build up to toxic levels that then cause the adverse reaction.

How Long to Wait Before Drinking After Flagyl

It’s recommended to avoid drinking any alcohol for at least 3 days after finishing treatment with Flagyl. This allows time for the medication to be eliminated from your body and prevents potential interactions.

Flagyl has a half-life of about 8-10 hours on average. This means it takes around 1-2 days for the drug to be cleared from your system. Giving it at least 72 hours (3 days) provides a buffer of safety to ensure the antibiotic is no longer in your bloodstream and tissue before consuming alcohol again.

Some doctors may advise avoiding alcohol for 5-7 days after finishing Flagyl, especially if you’ve been on a longer course of the antibiotic. This extended wait time helps prevent any lingering medicine interactions.

Are There Any Safe Alcohol Choices With Flagyl?

There is no universally agreed upon “safe” level of alcohol consumption while taking Flagyl. The effects can be unpredictable and vary between individuals. Even small amounts of alcohol have the potential to cause a reaction.

As such, it is recommended to avoid alcoholic beverages completely during treatment and for a few days afterwards. This includes beer, wine, liquor, and other drinks containing ethanol.

Some people mistakenly believe that certain alcohols like red wine or light beer may be safe in moderation. However, there have been reports of side effects occurring even with very minimal alcohol intake. It’s simply better to abstain altogether when on Flagyl.

Risks of Drinking While on Flagyl

Aside from the unpleasant short-term side effects, drinking while taking Flagyl can also pose the following risks:

  • Decreased effectiveness of Flagyl: Alcohol can interfere with how efficiently your body absorbs and processes Flagyl. This may render the antibiotic less effective for treating the infection.
  • Dangerous medication interactions: Mixing Flagyl and alcohol can amplify the side effects of certain other medications you may be taking, such as sedatives, sleeping pills, antidepressants, and opioids.
  • Severe allergic reaction: In rare cases, some people may be at risk of anaphylactic shock if they drink while taking Flagyl. Seek emergency care if you develop any symptoms of a severe allergic reaction like swelling, hives, trouble breathing, etc.
  • Liver toxicity: Excessive concurrent use of Flagyl and alcohol has been associated with some cases of liver injury. Speak to your doctor if you develop symptoms like abdominal pain, nausea, fatigue, or yellowing of the skin or eyes.

To avoid any added risks, it is critical not to consume alcohol while on a course of Flagyl and for a few days afterwards until the medication has completely cleared your system.

What to Do if You’ve Taken Flagyl and Alcohol

If you’ve accidentally or unknowingly consumed alcohol soon after taking Flagyl, stop drinking alcohol immediately. Here are some steps to help manage any side effects:

  • Drink plenty of water to help dilute the alcohol and Flagyl in your system.
  • Get some rest and wait for the side effects to resolve on their own within a few hours.
  • Take over-the-counter anti-nausea medication like Pepto-Bismol if experiencing nausea, vomiting, or cramps.
  • Use pain relievers like acetaminophen or ibuprofen for headaches.
  • Seek medical attention if symptoms are severe, persistent, or worsening.
  • Monitor yourself for potential late side effects over the next few days.
  • Let your doctor know about the alcohol and Flagyl interaction.
  • Avoid any further alcohol intake while finishing your course of Flagyl.

With proper monitoring and care, the reaction should resolve on its own. However, speak to your healthcare provider if you have ongoing bothersome symptoms or concerns after taking Flagyl and alcohol together.

Preventing Alcohol and Flagyl Interactions

To avoid any alcohol-related side effects while on Flagyl, be sure to take the following precautions:

  • Check the medication guide and warning labels for your Flagyl prescription.
  • Let your pharmacist and doctor know if you drink alcohol regularly so they can advise accordingly.
  • Read the ingredients carefully on medications, cough syrups, and mouthwashes, as some contain alcohol.
  • Ask your doctor when it will be safe to drink again after finishing Flagyl.
  • Abstain from alcohol for at least 3 days after your last Flagyl dose.
  • Remind friends or family you are avoiding alcohol while on the antibiotic.
  • Rinse your mouth after using alcohol-containing mouthwashes.

Being vigilant and proactive can help prevent any potential reactions between Flagyl and alcohol.


Drinking alcohol within a few days of taking Flagyl can cause severe nausea, vomiting, cramps, flushing, headaches, rapid heart rate, and other unpleasant reactions. You should avoid all alcohol while taking Flagyl and for at least 3 days after finishing the antibiotic treatment. There is no universally safe amount of alcohol consumption with Flagyl in your system. Let your healthcare providers know if you accidentally drank alcohol soon after taking Flagyl, and be sure to hydrate and rest until the side effects resolve. With proper care and prevention, you can avoid alcohol-related reactions from Flagyl.