Generic Name: metronidazole (MET-roe-NYE-da-zole)
Brand Name: Generic only. No brands available.
Long-term use of metronidazole has caused cancer in mice and rats. Discuss any questions or concerns with your doctor. Do not use metronidazole for a condition other than the one for which it was prescribed.
Metronidazole is used for:
Treating infections caused by certain bacteria and preventing infection before, during, and after certain surgeries. It may also be used for other conditions as determined by your doctor.
Metronidazole is an antibacterial agent. It is thought to work by entering the bacterial cell, acting on some components of the cell, and destroying the bacteria.
Do NOT use metronidazole if:
- you are allergic to any ingredient in metronidazole or to other nitroimidazoles (eg, tinidazole)
- you are in the first 3 months of pregnancy
- you are taking busulfan, an ergot alkaloid (eg, ergotamine), or you have taken disulfiram within the past 2 weeks
- you are taking an HIV protease inhibitor that contains alcohol (eg, amprenavir solution); check with your pharmacist if you are unsure if the medicine contains alcohol
- you drink alcohol
Contact your doctor or health care provider right away if any of these apply to you.
Before using metronidazole:
Some medical conditions may interact with metronidazole. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:
- if you are pregnant, planning to become pregnant, or are breast-feeding
- if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
- if you have allergies to medicines, foods, or other substances
- if you have nerve, brain, or blood problems; Crohn disease; or a history of liver problems or seizures
- if you have heart problems (eg, congestive heart failure) or a history of swelling of the hands, legs, or feet
Some MEDICINES MAY INTERACT with metronidazole. Tell your health care provider if you are taking any other medicines, especially any of the following:
- Disulfiram because side effects, such as mental or mood changes, may occur
- Amiodarone because the risk of irregular heartbeat may be increased
- Barbiturates (eg, phenobarbital) or phenytoin because they may decrease metronidazole's effectiveness
- Anticoagulants (eg, warfarin), busulfan, cyclosporine, ergot alkaloids (eg, ergotamine), HIV protease inhibitors containing alcohol (eg, amprenavir solution), lithium, or macrolide immunosuppressants (eg, tacrolimus) because the risk of their side effects may be increased by metronidazole
- Corticosteroids (eg, prednisone) because the risk of side effects may be increased
This may not be a complete list of all interactions that may occur. Ask your health care provider if metronidazole may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.
How to use metronidazole:
Use metronidazole as directed by your doctor. Check the label on the medicine for exact dosing instructions.
- Metronidazole is usually given as an injection at your doctor's office, hospital, or clinic. If you will be using metronidazole at home, a health care provider will teach you how to use it. Be sure you understand how to use metronidazole. Follow the procedures you are taught when you use a dose. Contact your health care provider if you have any questions.
- Do not use metronidazole if it contains particles, is cloudy or discolored, or if the vial is cracked or damaged.
- To clear up your infection completely, use metronidazole for the full course of treatment. Keep using it even if you feel better in a few days.
- Keep this product, as well as syringes and needles, out of the reach of children and pets. Do not reuse needles, syringes, or other materials. Ask your health care provider how to dispose of these materials after use. Follow all local rules for disposal.
- If you miss a dose of metronidazole, use it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not use 2 doses at once.
Ask your health care provider any questions you may have about how to use metronidazole.
Important safety information:
- Metronidazole may cause dizziness. This effect may be worse if you take it with alcohol or certain medicines. Use metronidazole with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
- Do not drink alcohol while you are using metronidazole and for at least 1 day after the last dose.
- Contact your doctor right away if stomach pain or cramps, severe diarrhea, or bloody stools occur. Do not treat diarrhea without first checking with your doctor.
- Metronidazole only works against bacteria; it does not treat viral infections (eg, the common cold).
- Be sure to use metronidazole for the full course of treatment. If you do not, the medicine may not clear up your infection completely. The bacteria could also become less sensitive to this or other medicines. This could make the infection harder to treat in the future.
- Long-term or repeated use of metronidazole may cause a second infection. Tell your doctor if signs of a second infection occur. Your medicine may need to be changed to treat this.
- Some patients have developed persistent nerve problems (peripheral neuropathy) after using metronidazole for a long period of time. Tell your doctor right away if you develop signs of nerve problems (eg, numbness; tingling; burning of the arms, hands, legs, feet). Do NOT take more than the recommended dose or use for longer than prescribed without checking with your doctor.
- Metronidazole may interfere with certain lab tests. Be sure your doctor and lab personnel know you are using metronidazole.
- Lab tests, including liver function and white blood cell counts, may be performed while you use metronidazole. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
- Use metronidazole with caution in the ELDERLY; they may be more sensitive to its effects.
- Metronidazole should be used with extreme caution in CHILDREN; safety and effectiveness in children have not been confirmed.
- PREGNANCY and BREAST-FEEDING: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using metronidazole while you are pregnant. Do not use metronidazole in the first 3 months of pregnancy. Metronidazole is found in breast milk. Do not breast-feed while using metronidazole.
Possible side effects of metronidazole:
All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:
Seek medical attention right away if any of these SEVERE side effects occur:
Appetite loss; constipation; diarrhea; dizziness; headache; metallic taste; nausea; pain, swelling, or redness at the injection site; stomach upset; vomiting.
Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue; fever; flushing; stuffy nose; very dry mouth or vagina); bloody stools; decreased coordination; increased or decreased urination; numbness, tingling, or burning of the arms, hands, legs, or feet; red, swollen, blistered, or peeling skin; seizures; severe diarrhea; severe or persistent dizziness or headache; sore throat, chills, or fever; speech problems; stiff neck; stomach pain or cramps; vaginal itching, odor, or discharge; vision loss or other vision changes; white patches in the mouth.
This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.
If OVERDOSE is suspected:
Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center, or emergency room immediately. Symptoms may include nausea; seizures; vomiting.Proper storage of metronidazole:
Metronidazole is usually handled and stored by a health care provider. If you are using metronidazole at home, store metronidazole as directed by your pharmacist or health care provider.
- If you have any questions about metronidazole, please talk with your doctor, pharmacist, or other health care provider.
- Metronidazole is to be used only by the patient for whom it is prescribed. Do not share it with other people.
- If your symptoms do not improve or if they become worse, check with your doctor.
- Check with your pharmacist about how to dispose of unused medicine.
This information should not be used to decide whether or not to take metronidazole or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about metronidazole. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to metronidazole. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your healthcare provider for complete information about the risks and benefits of using metronidazole.
Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your healthcare provider for complete information about the risks and benefits of using this medicine.
More metronidazole resources
- metronidazole Intravenous Advanced Consumer (Micromedex) - Includes Dosage Information
- Flagyl Prescribing Information (FDA)
- Flagyl Oral, Intravenous Advanced Consumer (Micromedex) - Includes Dosage Information
- Flagyl Consumer Overview
- Flagyl ER Prescribing Information (FDA)
- Metronidazole Prescribing Information (FDA)
- Metronidazole Monograph (AHFS DI)
- Metronidazole Professional Patient Advice (Wolters Kluwer)
Compare metronidazole with other medications
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- Bacterial Infection
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- Bone infection
- Clostridial Infection
- Crohn's Disease, Acute
- Crohn's Disease, Maintenance
- Deep Neck Infection
- Dental Abscess
- Helicobacter Pylori Infection
- Intraabdominal Infection
- Joint Infection
- Pelvic Inflammatory Disease
- Pseudomembranous Colitis
- Skin Infection
- Surgical Prophylaxis