What Does Metronidazole Do to the Body?

Metronidazole is a commonly prescribed medication used to treat certain types of bacterial infections. In the United States, it is also available under the brand name Flagyl, which is manufactured by Pfizer. It can be taken both orally or topically, depending on the type of infection it is being used to treat. Many people taking metronidazole will experience no side effects, but there are some to be aware of.

How It Works

• Metronidazole works by entering the cells of bacteria and killing them, which in turn treats an infection.

When Is It Used?

• Metronidazole is commonly prescribed to treat bacterial infections in the respiratory tract, stomach, skin, vagina and joints.

Serious Side Effects

• Some side effects of metronidazole might be an indication of a serious complication. Contact your doctor if you experience seizures, watery or bloody diarrhea, numbness in the hands and feet, fever or flu-like symptoms, pain while urinating or white sores or spots in the mouth.

Non-Serious Side Effects

• Some people taking metronidazole will experience nausea and vomiting, vaginal itching, cough, nasal congestion, a sore or swollen tongue, a bad taste in the mouth, headaches and dizziness.

Warnings

• Consuming alcohol at any time while taking metronidazole, or for three days after stopping can cause uncomfortable sensations, such as a rapid heart beat, warmth under the skin, and nausea and vomiting.