Alcohol can interact with antibiotics like Flagyl. A commonly prescribed antibiotic, Flagyl treats bacterial and parasitic infections, including those in the vagina, abdomen, and skin. Flagyl is also available in its generic name, metronidazole.

While some antibiotics are safe to take while drinking a moderate amount of alcohol, unfortunately, Flagyl is not one of them. Mixing alcohol and Flagyl can cause and worsen side effects.

Side Effects of Mixing Alcohol and Flagyl

The body relies on specific enzymes to break down alcohol into substances that can be eliminated. Several by-products are created through this complex process. One of the byproducts is a toxic substance called acetaldehyde. Flagyl can prevent the functioning of enzymes that are responsible for breaking down acetaldehyde.

When this interaction happens, acetaldehyde can build up in the body, leading to many side effects, including:

  • Abdominal cramps
  • Nausea
  • Vomiting
  • Headache
  • Flushing

These effects usually occur five to 15 minutes after consuming alcohol.

Flagyl can increase a person’s sensitivity to alcohol. Even having a small amount of alcohol while on Flagyl can make some people very sick, and they experience not only nausea and vomiting but also the feeling of shortness of breath. Some other side effects of mixing alcohol and Flagyl may include:

  • Changes in blood pressure
  • Liver damage
  • Rapid heart rate
  • Stomach pain
  • Hot flashes

How Long Flagyl Stays in Your System

Even after your last dose of Flagyl, it remains in your system for some time. Flagyl may be cleared from your body within 48 hours, but the elimination rate varies depending on a person’s age and metabolism, among other factors.

The Flagyl manufacturer recommends waiting at least one day after the last dose of Flagyl before drinking alcohol. However, some experts recommending waiting up to three days after the last dose.

Another factor that may affect how long Flagyl stays in the system is liver functioning. The liver eliminates metronidazole from the body, so if you have impaired liver function because of alcoholism or any other reason, you should let your doctor know.

Key Points: Alcohol and Flagyl

Serious interactions can occur from taking Flagyl and drinking even a small amount of alcohol. Because of this reason, avoid drinking and taking Flagyl. Important points to remember about alcohol and Flagyl include:

  • It is not recommended to drink alcohol while taking antibiotics like Flagyl
  • Even a small amount of alcohol can react badly with Flagyl
  • The combination of Flagyl and alcohol can cause serious side effects including hot flashes, blood pressure changes, and liver damage
  • If you need to take antibiotics and plan on drinking alcohol, be sure to tell your doctor
  • If you are finishing up a course of Flagyl, wait a few days before drinking alcohol

If you or a loved one need treatment for an alcohol use disorder, don’t wait to get help. The Recovery Village offers specialized alcohol addiction treatment programs at centers across the country. Call today to learn more about treatment options that could work for you.

  1. Steckelberg, James M. “What are the effects of drinking alcohol while taking antibiotics?” Published on February 6, 2018. Accessed March 22, 2019.
  2. Heleon MW, White M. “Disulfuram-cotrimoxazole reaction.” Published in July 1998. Accessed March 22, 2019
  3. University of Michigan. “Metronidazole”. (n.d.). Accessed March 23, 2019.
  4. Watson Labs. “Metronidazole Package Insert”. Updated February 6, 2006. Accessed March 23, 2019.
  5. NHS. “When can I drink alcohol after finishing metronidazole?” Last updated 2018. Accessed March 2019.