What Happens When Flagyl (Metronidazole) And Alcohol Are Mixed?

This article is about the consequences of combining Flagyl (Metronidazole) and alcohol. Although it is one of the lesser-known drugs, it is a solid antibiotic prescribed to treat various bacterial and parasitic infections.

  • Since the liver and intestines process and break down this drug in the body, side effects primarily impact the gastrointestinal system and include nausea, vomiting, diarrhea, stomach cramps, and constipation.
  • The liver also metabolizes alcohol. Between two and eight percent of one alcoholic beverage is excreted through sweat and urine. The liver metabolizes the remaining percentage.

Initially, during processing, alcohol is to a toxic chemical called acetaldehyde, a form of formaldehyde converted to acetyl radicals. When someone drinks too much alcohol, the liver cannot keep up with converting acetaldehyde into acetyl radicals.

  • Accumulating acetaldehyde in the bloodstream can lead to vomiting, hangovers, or, worst of all, alcohol poisoning.

Although it is not advisable, drinking a beer or small glass of wine while taking Flagyl typically causes side effects in most people, such as;

  • Nausea
  • Vomiting
  • Diarrhea

Depending on how much alcohol, a disulfiram reaction resulting from mixing alcohol and this drug could last up to two hours. If symptoms are severe, emergency medical treatment may be necessary to prevent dehydration and fainting due to hyperventilation. Alcoholics taking disulfiram to suppress cravings should not take this drug.

Occasionally, mixing this drug with alcohol may trigger a response resembling signs of disulfiram reaction. It is due to alcohol interfering with the ability of the liver to metabolize it.

Side effects of a disulfiram reaction can include:

  • Throbbing headache
  • Flushing/sweating
  • Nausea/vomiting
  • Rapid heartbeat
  • Heart palpitations
  • Dizziness
  • Blurry vision

Psychotic reactions such as hallucinations, paranoid delusions, and extreme agitation could even occur in alcohol abusers who have small amounts of disulfiram in their bloodstream.

Some people are susceptible to this drug blocking the metabolization of propylene glycol by the liver. Propylene glycol is a commonly used ingredient found in injectable, oral, and topical medications to facilitate the dispersion of the medicine.

Excess amounts of propylene glycol in the body could cause:

  • Tachycardia
  • Seizures
  • Acute kidney failure

According to drugs.com, “Patients treated with metronidazole should continue to avoid using any products containing alcohol or propylene glycol for at least three days until after completion of therapy.”

If prescribed, always tell your physician if you are currently taking or plan on taking any one of the following:

  • Ibuprofen
  • Aspirin
  • Benadryl
  • Antidepressants
  • Mucinex
  • Lyrica
  • Hydrocodone/acetaminophen
  • Acetaminophen
  • Probiotics
  • Prednisone
  • Vitamins B12, C or D3
  • Warfarin
  • Xanax

Most antibiotics will remain effective if alcohol goes with them—however, the ability of some antibiotics to eliminate infectious bacteria or parasites by alcohol. For example, an antibiotic called doxycycline loses its effectiveness when mixed with alcohol.

(image courtesy of https://dailymed.nlm.nih.gov/)