Metronidazole is used to treat a variety of infections. It belongs to a class of antibiotics known as nitroimidazoles. It works by stopping the growth of bacteria and protozoa.

This antibiotic only treats bacterial and protozoal infections. It will not work for viral infections (e.g., common cold, flu). Unnecessary use or overuse of any antibiotic can lead to its decreased effectiveness.

This medication may be taken with food or a full glass of water or milk to prevent stomach upset. Dosage is based on your medical condition, the type of infection being treated, and your response to therapy.

Antibiotics work best when the amount of medicine in your body is kept at a constant level. Therefore, take this drug at evenly spaced intervals.

Continue to take this medication until the full prescribed amount is finished, even if symptoms disappear after a few days. Stopping the medication too early may allow bacteria/protozoa to continue to grow, which may result in a relapse of the infection.

Inform your doctor if your condition persists or worsens.

Dizziness, headache, diarrhea, nausea, stomach pain, loss of appetite, constipation, changes in taste, and dry mouth may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly.

This drug may cause urine to darken in color. This is harmless.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if any of these unlikely but serious side effects occur: unsteadiness, seizures, mental/mood changes, numbness/tingling of hands/feet, painful urination.

Tell your doctor immediately if any of these rare but very serious side effects occur: sore throat, persistent fever, unusual bleeding/bruising, severe stomach pain, persistent nausea/vomiting.

This medication may rarely cause a severe intestinal condition (Clostridium difficile-associated diarrhea) due to a type of resistant bacteria. This condition may occur during treatment or weeks to months after treatment has stopped. Do not use anti-diarrhea products or narcotic pain medications if you have any of the following symptoms because these products may make them worse. Tell your doctor immediately if you develop: persistent diarrhea, abdominal or stomach pain/cramping, blood/mucus in your stool.

Use of this medication for prolonged or repeated periods may result in oral thrush or a new vaginal yeast infection (oral or vaginal fungal infection). Contact your doctor if you notice white patches in your mouth, a change in vaginal discharge, or other new symptoms.

A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction may include: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking metronidazole, tell your doctor or pharmacist if you are allergic to it; or to other nitroimidazoles such as tinidazole; or if you have any other allergies.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: liver problems, nervous system disorders (e.g., seizures), blood disorders, Crohn's disease.

Avoid alcoholic beverages while taking this medication and for at least 1 day (3 days if you are taking the oral capsules) after finishing this medicine because drinking alcohol may result in severe stomach upset/cramps, nausea, vomiting, headache and flushing.

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.

The elderly may be at greater risk for side effects while using this drug.

Tell your doctor if you are pregnant before using this drug. It should not be used during the first 3 months of pregnancy and used only with caution during the last 6 months, unless your infection has not improved on other antibiotics.

This medication passes into breast milk. Therefore, breast-feeding is not recommended while using this drug. Consult your doctor before breast-feeding.

Your healthcare professionals (e.g., doctor or pharmacist) may already be aware of any possible drug interactions and may be monitoring you for it. Do not start, stop or change the dosage of any medicine before checking with them first.

This drug should not be used with the following medications because very serious interactions may occur: alcohol-containing products (e.g., cough and cold syrups, aftershave), amprenavir oral solution, disulfiram, lopinavir/ritonavir oral solution.

If you are currently using any of these medications listed above, tell your doctor or pharmacist before starting metronidazole.

Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: "blood thinners" (e.g., warfarin), busulfan, cimetidine, fluorouracil, lithium, live bacterial vaccines, drugs for seizures (e.g., phenobarbital, phenytoin).

This medication may interfere with certain laboratory tests (including liver function tests, blood triglyceride levels), possibly causing false test results. Make sure laboratory personnel and your doctors know you use this drug.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US national poison hotline at 1-800-222-1222. Canadian residents should call their local poison control center directly. Symptoms of overdose may include nausea, vomiting, severe dizziness, and seizures.

Do not share this medication with others.

Treatment of certain infections (trichomoniasis) may require that sexual partners be treated as well to avoid re-infection. During therapy, refrain from sexual intercourse or always use a condom.

This medication has been prescribed for your current condition only. Do not use it later for another infection unless told to do so by your doctor. A different medication may be necessary in those cases.

Laboratory and/or medical tests (e.g., blood counts) should be performed from time to time to monitor your progress or check for side effects. Consult your doctor for more details.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

Tablets should be stored at room temperature below 77 degrees F (25 degrees C) away from light. Capsules should be stored at or below room temperature between 59-77 degrees F (15-25 degrees C). Do not store in the bathroom. Keep all medicines away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.

Information last revised March 2009 Copyright(c) 2009 First DataBank, Inc.