Flagyl is used for:
Treating certain infections caused by bacteria or amoebas. It may also be used for other conditions as determined by your doctor.

Flagyl is an oral antiprotozoal and antibacterial. It is thought to work by entering the bacterial cell, acting on some components of the cell and destroying the bacteria.

Do NOT use Flagyl if:
you are allergic to any ingredient in Flagyl 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 Flagyl :
Some medical conditions may interact with Flagyl . 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

Some MEDICINES MAY INTERACT with Flagyl . Tell your health care provider if you are taking any other medicines, especially any of the following:
Barbiturates (eg, phenobarbital) or phenytoin because they may decrease Flagyl 's effectiveness
Anticoagulants (eg, warfarin), busulfan, ergot alkaloids (eg, ergotamine), HIV protease inhibitors containing alcohol (eg, amprenavir solution), lithium, or macrolide immunosuppressants (eg, tacrolimus) because their risk of side effects may be increased by Flagyl
Disulfiram because side effects, such as mental or mood changes, may occur
Oral contraceptives (eg, birth control pills) because their effectiveness may be decreased by Flagyl

This may not be a complete list of all interactions that may occur. Ask your health care provider if Flagyl 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 Flagyl :
Use Flagyl as directed by your doctor. Check the label on the medicine for exact dosing instructions.
Take Flagyl by mouth with food.
To clear up your infection completely, take Flagyl for the full course of treatment. Keep taking it even if you feel better in a few days.
If you miss a dose of Flagyl , take 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 take 2 doses at once.

Ask your health care provider any questions you may have about how to use Flagyl .

Important safety information:
Flagyl may cause dizziness. These effects may be worse if you take it with alcohol or certain medicines. Use Flagyl 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 taking Flagyl 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.
Flagyl only works against bacteria; it does not treat viral infections (eg, the common cold).
Be sure to use Flagyl 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 Flagyl 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.
Hormonal birth control (eg, birth control pills) may not work as well while you are using Flagyl . To prevent pregnancy, use an extra form of birth control (eg, condoms).
Flagyl may interfere with certain lab tests. Be sure your doctor and lab personnel know you are taking Flagyl .
Lab tests, including liver function and white blood cell counts, may be performed while you use Flagyl . These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
Use Flagyl with caution in the ELDERLY; they may be more sensitive to its effects.
Flagyl 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 Flagyl while you are pregnant. Do not use Flagyl in the first 3 months of pregnancy. Flagyl is found in breast milk. Do not breast-feed while taking Flagyl .

Possible side effects of Flagyl :
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:

Appetite loss; constipation; diarrhea; dizziness; headache; metallic taste; nausea; stomach upset; vomiting.
Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); bloody stools; increased or decreased urination; numbness, tingling, or burning of your arms, hands, legs, or feet; seizures; severe diarrhea; sore throat, chills, or fever; stomach pain or cramps; vaginal itching, odor, or discharge; white patches in the mouth.