In the U.S.—

In Canada—

• Anti-infective, vaginal

Metronidazole (me-troe-NI-da-zole) is used to treat certain vaginal infections. It works by killing bacteria. This medicine will not work for vaginal fungus or yeast infections.

Metronidazole is available only with your doctor's prescription, in the following dosage forms:

Vaginal
• Cream (Canada)
• Gel (U.S. and Canada)
• Tablets (Canada)

In deciding whether to use a medicine, the risks of using the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For vaginal metronidazole, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to metronidazole. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Vaginal metronidazole has not been studied in pregnant women. Metronidazole given by mouth (e.g., Flagyl) has not been shown to cause birth defects. Before taking this medicine, make sure your doctor knows if you are pregnant or if you may become pregnant.

Breast-feeding—Use is not recommended in nursing mothers since metronidazole passes into breast milk and may cause unwanted effects in the baby. In addition, metronidazole may change the taste of your breast milk. Your doctor may want you to stop breast-feeding and use this medicine for a short time. During this time the breast milk should be pumped or drawn out with a breast pump and thrown away. Two days after you finish using this medicine, you may go back to breast-feeding.

Children—Studies on these medicines have been done only in adult patients, and there is no specific information comparing use of vaginal metronidazole in children with use in other age groups.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of metronidazole in the elderly with use in other age groups.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are using vaginal metronidazole it is especially important that your health care professional know if you are taking any of the following:

• Alcohol or alcohol-containing medicines (e.g., NyQuil, Geritol)—Metronidazole can cause serious side effects such as abdominal cramping, flushing, headache, nausea, or vomiting when it is used with alcohol

• Anticoagulants (blood thinners)—Taking metronidazole may increase the effects of anticoagulants, changing the amount you need to take

• Disulfiram (e.g., Antabuse)—Severe confusion or mental problems can occur if metronidazole is used together with disulfiram or if it is used up to 2 weeks after disulfiram treatment has been stopped

• Central nervous system (CNS) disease, including epilepsy—Metronidazole may increase the chance of seizures (convulsions) or other side effects

• Liver disease, severe—Patients with severe liver disease may have an increase in side effects

• Low white blood cell count (or history of)—Metronidazole may make the condition worse

Wash your hands before and after using the medicine. Also, keep the medicine out of your eyes.

If this medicine does get into your eyes, wash them out immediately, but carefully, with large amounts of tap water. If your eyes still burn or are painful, check with your doctor.

Vaginal metronidazole products usually come with patient directions. Read them carefully before using this medicine.

Use vaginal metronidazole exactly as directed by your doctor.

• To fill the applicator
  • For cream or gel dosage forms:
    • Break the metal seal at the opening of the tube by using the point on the top of the cap.
    • Screw the applicator onto the tube.
    • Squeeze the medicine into the applicator slowly until it is full.
    • Remove the applicator from the tube. Replace the cap on the tube.
  • For vaginal tablet dosage form:
    • Place the vaginal tablet into the applicator. Wet the vaginal tablet with water for a few seconds.
• To insert vaginal metronidazole using the applicator
  • For all dosage forms:
    • Relax while lying on your back with your knees bent.
    • Hold the full applicator in one hand. Insert it slowly into the vagina. Stop before it becomes uncomfortable.
    • Slowly press the plunger until it stops.
    • Withdraw the applicator. The medicine will be left behind in the vagina.
• To care for the applicator
  • For all dosage forms:
    • Clean the applicator after use by pulling the plunger out of the applicator and washing both parts completely in warm soapy water.
    • Rinse well.
    • After drying the applicator, replace the plunger.

To help clear up your infection completely, it is very important that you keep using this medicine for the full time of treatment , even if your symptoms begin to clear up after a few days. If you stop using this medicine too soon, your symptoms may return. Do not miss any doses. Also, continue using this medicine even if your menstrual period starts during the time of treatment .

Dosing—

The dose of vaginal metronidazole will be different for different patients. The following information includes only the average doses of vaginal metronidazole. If your dose is different, do not change it unless your doctor tells you to do so.

• Forvaginal cream dosage form:
  • For bacterial vaginosis or trichomoniasis:
    • Adults and teenagers—One applicatorful (500 milligrams [mg]), inserted into the vagina. Use the medicine one or two times a day for ten or twenty days.
    • Children—Use and dose must be determined by your doctor.
• Forvaginal gel dosage form:
  • For bacterial vaginosis:
    • Adults and teenagers—One applicatorful (37.5 mg), inserted into the vagina one or two times a day for five days.
    • Children—Use and dose must be determined by your doctor.
• Forvaginal tablets dosage form:
  • For bacterial vaginosis or trichomoniasis:
    • Adults and teenagers—One 500-mg tablet, inserted high into the vagina. Use the medicine once a day in the evening for ten or twenty days.
    • Children—Use and dose must be determined by your doctor.

Missed dose—

If you miss a dose of this medicine, use it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store the vaginal tablets in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Keep this medicine from freezing.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

If your symptoms do not improve within a few days, or if they become worse, check with your doctor.

It is important that you visit your doctor after you have used all your medicine to make sure that the infection is gone.

Drinking alcoholic beverages while using this medicine may cause stomach pain, nausea, vomiting, headache, or flushing or redness of the face. Alcohol-containing medicines (for example, elixirs, cough syrups, tonics) may also cause problems. The chance of these problems occurring may continue for at least a day after you stop using metronidazole. Therefore, you should not drink alcoholic beverages or take other alcohol-containing medicines while you are using this medicine and for at least a day after stopping it.

This medicine may cause some people to become dizzy or lightheaded. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or are not alert. If these reactions are especially bothersome, check with your doctor.

Vaginal medicines usually leak out of the vagina during treatment. To keep the medicine from getting on your clothing, wear a minipad or sanitary napkin. Do not use tampons (like those used for menstrual periods) since they may soak up the medicine.

To help clear up your infection completely and to help make sure it does not return, good health habits are also required.

• Wear cotton panties (or panties or pantyhose with cotton crotches) instead of synthetic (for example, nylon or rayon) panties.
• Wear only freshly washed panties daily.

Do not have sexual intercourse while you are using this medicine. Having sexual intercourse may reduce the strength of the medicine. This may cause the medicine to not work as well. Also, oils in the cream and vaginal tablets (but not the vaginal gel) may damage latex (rubber) contraceptive devices, such as cervical caps, condoms, or diaphragms, causing them to leak, wear out sooner, or not work properly.

Many vaginal infections (for example, trichomoniasis) are spread by having sexual intercourse. You can give the infection to your sexual partner, and the infection could be given back to you. Your partner may also need to be treated for some infections. Until you are sure that the infection is completely cleared up after your treatment with this medicine, your partner should wear a condom during sexual intercourse . If you have any questions about this, check with your health care professional.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• More common
  • Itching in the vagina;  pain during sexual intercourse;  thick, white vaginal discharge with no odor or with a mild odor 
  
  

• Less common
  • Abdominal or stomach cramping or pain;  burning or irritation of penis of sexual partner;  burning on urination or need to urinate more often;  itching, stinging or redness of the genital area 
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

• Less common
  • Diarrhea;  dizziness or lightheadedness ;  dryness of mouth;  headache ;  feeling of a furry tongue;  loss of appetite;  metallic taste or other change in taste sensation;  nausea;  vomiting 
  
  

Metronidazole may cause your urine to become dark. This is harmless and will go away when you stop using this medicine.

After you stop using this medicine, your body may need time to adjust. The length of time this takes depends on the amount of medicine you were using and how long you used it. During this period of time check with your doctor if you notice any of the following side effects:

• Any vaginal or genital irritation or itching;  pain during sexual intercourse;  thick, white vaginal discharge not present before treatment, with no odor or with a mild odor 

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.