Active Ingredient

Metronidazole

Metronidazole is an antibiotic and antiparasitic medication. It is commonly used to treat various infections caused by bacteria and parasites.

It is effective against certain types of bacteria and protozoa, making it a versatile option for treating infections in different parts of the body.

Written By Douglas C. Goldberg, MD

Reviewed By Philip Schein, MD

Last Updated 28 Nov 2025

Available Metronidazole Brands

Flagyl ER

Strengths 200mg, 400mg

Metronidazole Uses

Metronidazole is prescribed for a variety of infections. It is important to follow your doctor’s advice on its use.

Bacterial infections of the vagina
Infections of the gastrointestinal tract
Skin infections
Dental infections
Protozoal infections like amoebiasis

How Metronidazole Works

Metronidazole works by entering the cells of bacteria and parasites and disrupting their DNA. This action stops the organisms from growing and reproducing, helping to eliminate the infection.

It belongs to a class of drugs known as nitroimidazoles, which target anaerobic bacteria and certain parasites.

Common side effects of Metronidazole

Not everyone experiences side effects with Metronidazole, and many are mild and temporary. However, if you notice any concerning symptoms, consult your doctor.

Nausea
Headache
Dizziness
Metallic taste in the mouth
Stomach upset
Loss of appetite

If you experience serious or persistent side effects, seek medical attention promptly.

Avoid drinking alcohol while taking Metronidazole and for a few days after finishing the course, as it can cause adverse reactions.
Inform your doctor about any other medications you are taking to avoid potential interactions.
Do not use Metronidazole if you have had an allergic reaction to it in the past.
Contact your doctor if you experience unusual symptoms, such as numbness or tingling.
Complete the full course as prescribed, even if you start feeling better.

Always consult your healthcare provider for advice specific to your health condition.

Frequently Asked Questions

What does Metronidazole treat?

Metronidazole is used to treat various bacterial and protozoal infections, including those affecting the vagina, gastrointestinal tract, skin, and mouth.

How quickly does Metronidazole work?

The time it takes for Metronidazole to work can vary, but some patients may start to feel better within a few days of starting treatment.

Can I drink alcohol while taking Metronidazole?

It is advised to avoid alcohol during treatment and for a few days after completing Metronidazole to prevent adverse reactions.

Are there any foods or drinks I should avoid while taking Metronidazole?

Apart from alcohol, there are generally no specific foods or drinks to avoid, but it’s always good to follow your doctor’s advice.

What should I do if I miss a dose of Metronidazole?

If you miss a dose, take it as soon as you remember. If it’s almost time for the next dose, skip the missed dose and continue with your regular schedule.