Generic Name: Flagyl Brand Name(s): Generics only. No brands available.


What is Flagyl ® (metronidazole) used for?

Flagyl ® is commonly used to treat bacterial infections of the vagina, stomach, skin, joints, and respiratory tract. This medication will not treat a vaginal yeast infection.

How should I take Flagyl ® (metronidazole)?

Take Flagyl ® exactly as prescribed by your doctor. Take this drug by mouth. Do not chew or crush. Drink with a full glass of water.

Do not take in larger or smaller amounts or for longer than recommended. Follow the directions on your prescription label.

How do I store Flagyl ® (metronidazole)?

Flagyl ® is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store Flagyl ® in the bathroom or the freezer. There may be different brands of Flagyl ® that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush Flagyl ® down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using Flagyl ® (metronidazole)?

Before taking Flagyl ®, tell your doctor or pharmacist if:

  • You are pregnant or breastfeeding. This is because, while you are expecting or feeding a baby, you should only take medicines on the recommendation of a doctor.
  • You are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
  • You have allergy with any of active or inactive ingredients of Flagyl ® or other medications.
  • You have any other illnesses, disorders, or medical conditions.

Avoid alcoholic beverages and products containing propylene glycol while taking this medication and for at least 3 days after finishing this medicine because severe stomach upset/cramps, nausea, vomiting, headache, and flushing may occur.

This drug may make you dizzy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely.

Is it safe during pregnancy or breastfeeding?

There are no adequate studies in women for determining risk when using Flagyl ® during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking Flagyl ®. Flagyl ® is pregnancy risk category B, according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

  • A=No risk
  • B=No risk in some studies
  • C=There may be some risk
  • D=Positive evidence of risk
  • X=Contraindicated
  • N=Unknown

Side effects

What side effects can occur from Flagyl ® (metronidazole)?

Less serious side effects may include:

  • Stomach pain
  • Diarrhea
  • Dizziness
  • Loss of balance
  • Vaginal itching or discharge
  • Dry mouth or unpleasant metallic taste
  • Cough, sneezing, runny or stuffy nose
  • Swollen or sore tongue

Contact your doctor immediately if you notice:

  • Numbness or tingling in your hands or feet
  • White patches or sores inside your mouth or on your lips
  • Pain or burning when you urinate
  • Diarrhea that is watery or bloody
  • Vision problems
  • Pain behind your eyes
  • Trouble concentrating
  • Slurred speech
  • Mood or behavior changes
  • Tremors
  • Muscle twitching
  • Seizure (convulsions)
  • Fever
  • Chills
  • Muscle pain
  • Confusion
  • Headache
  • Sore throat
  • Neck stiffness
  • Increased sensitivity to light
  • Drowsiness
  • Nausea and vomiting

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.


What drugs may interact with Flagyl ® (metronidazole)?

Flagyl ® may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Products may interact with this drug, including:

  • Alcohol-containing products (such as cough and cold syrups, aftershave)
  • Products containing propylene glycol, lopinavir/ritonavir solution, lithium
  • Disulfiram
  • Hormonal birth control such as pills, patch, or ring, a few antibiotics (such as rifampin, rifabutin)

Does food or alcohol interact with Flagyl ® (metronidazole)?

Flagyl ® may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with Flagyl ® (metronidazole)?

Flagyl ® may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.

These health conditions may include:

  • Liver disease
  • Kidney disease
  • Certain blood disorders (low blood cell counts)


The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using Flagyl ® (metronidazole).

What is the dose of Flagyl ® (metronidazole) for an adult?

Bacterial Infection

The recommended dose is 7.5 mg/kg orally every 6 hours, orally.


Acute intestinal amebiasis (acute amebic dysentery): The recommended dose is 750 mg orally 3 times a day for 5 to 10 days.

Amebic liver abscess: The recommended dose is 500 to 750 mg orally 3 times a day for 5 to 10 days.


1-day regimen: The recommended dose is 2 g orally as a single dose (or as 1 g twice on the same day).

7-day regimen: The recommended dose is 250 mg orally 3 times a day for 7 consecutive days.

Pelvic Inflammatory Disease

The recommended dose is 7.5 mg/kg orally every 6 hours, orally.

What is the dose of Flagyl ® (metronidazole) for a child?

Pseudomembranous Colitis

Children and adolescents: The recommended dose is 30 mg/kg/day orally in 4 divided doses.

How is Flagyl ® (metronidazole) available?

Flagyl ® is available in the following dosage forms and strengths:

  • Tablet 250mg

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of Flagyl ®, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.

Review Date: May 12, 2017 | Last Modified: May 12, 2017

You might also like