In this session, we will be discussing the consumer medication information for metronidazole, trade name FlagylTM.

What it’s for & How to take

Metronidazole is an antibiotic that works by blocking the growth of bacteria. This medication is used to treat a wide variety of infections.

Do not take an antibiotic without first being seen by a prescriber. Not all antibiotics work for all types of infections. If you take an antibiotic that is not prescribed for you, the condition might get worse.

Metronidazole will not work to treat the common cold or the flu. This antibiotic may not be effective if it has been overused in conditions that are not related to bacterial infections.

Metronidazole is usually prescribed to be taken 2-4 times daily or as directed by your physician. This antibiotic should be taken with food and a full glass of water.

Take this medication at evenly spaced intervals. Antibiotics work best when a constant level of the medication is maintained in the body.

If you forget to take a dose, take it as soon as you remember. If it is near the time of your next dose, skip it and continue with your normal dose time. Unless otherwise directed, do not take a double dose to make up the missed dose.

Take this medication until it is all done, even if you are feeling better and the symptoms are gone. If you stop taking your antibiotic, the infection might come back and may be harder to treat.

Most Important Warnings

  • Metronidazole has been shown to cause cancer in mice and rats. Avoid unnecessary use of this medication.
  • Avoid all forms of alcohol while taking metronidazole and for at least 24 hours after finishing this medicine. Alcohol taken with metronidazole may cause severe stomach cramping, nausea, vomiting, headache and severe flushing.

Other Warnings & Cautions

  • Antibiotic therapy may sometimes allow for growth of yeast in your mouth or cause a vaginal yeast infection in women. Tell your pharmacist or doctor if you have any symptoms of yeast in your mouth (such as white patches or a dry/chalky feeling your mouth) or any symptoms of a vaginal yeast infection (such as itching, discharge, redness or swelling).
  • Let your pharmacist or doctor know if you are pregnant or breastfeeding before taking metronidazole.
  • Some antibiotics may decrease the effect of birth control. If you are taking birth control, discuss this with your doctor or pharmacist before starting a course of therapy with metronidazole. You may need to use backup birth control.
  • Do not drive or do any activity that requires focus and attention until you are sure you can do them safely. Avoid alcoholic beverages while taking metronidazole. You may have unpleasant side effects, such as warmth and redness of skin, nausea or vomiting if you drink alcohol while taking this medication.

Interactions & Side Effects

  • Tell your pharmacist or doctor all your medication allergies so they may determine if metronidazole is safe for you to take.
  • Avoid dangerous drug interactions. Tell your pharmacist or doctor all the other medication you are taking, including over the counter supplements, even if you don’t take them very often.
  • Ask your doctor if this medication is safe to take with your current health conditions. Tell your doctor if you have liver or kidney disease, any other infections or any other medical conditions.
  • Metronidazole may cause your urine to have a dark color, this is normal with this medication and is harmless.
  • While taking metronidazole, you may have some nausea, diarrhea or vomiting. You may also feel some dizziness or a headache. If these or any other unwanted side effects persist, contact your doctor or pharmacist to talk about it with them.
  • Call your doctor right away if you have any severe abdominal pain, constant diarrhea, mucus or blood in your stool, any tingling in your hands or feet or any mood changes.
  • Call emergency 911 if you experience any seizures.

If you have any questions about what you have heard, contact your pharmacist or doctor. Ask your pharmacist how your medication should be stored and how you should dispose of it when you are done taking it. Do not share your medication with anyone, ever. Remember, this is not meant to replace your counseling session with your pharmacist. In case of overdose, call your local poison control center at 1-800-222-1222.

Updated 7/20