Metronidazole

Why is this medicine prescribed?

Metronidazole is used to treat certain infections in the body caused by bacteria including sexually transmitted diseases (STDs) and bacterial vaginosis (an infection caused by too much of certain types of harmful bacteria in the vagina) in women. Metronidazole is in a class of medications called nitroimidazole antimicrobials. It works by stopping the growth of bacteria.

Antibiotics will not work for colds, flu, or other viral infections. Using antibiotics when they are not needed increases your risk of getting an infection later that resists antibiotic treatment.

Are there other uses for this medicine?

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

How should this medicine be used?

Metronidazole comes as a tablet, a capsule, and suspension (liquid) to take by mouth. It is taken as a one-time dose (or divided into two doses on 1 day) or two to four times daily. Take metronidazole exactly as directed.

Shake the oral suspension well before each use so it mixes evenly. Use a dosing spoon, oral syringe, or measuring cup to measure the correct amount of medication. You may not receive the correct amount of medication if you use a household spoon to measure your dose.

Continue to take this medication even if you feel well. Do not stop taking it without talking to your doctor. If you stop taking this medication too soon or skip doses, your infection may not be completely treated and the bacteria may become resistant to antibiotics.

What special precautions should I follow?

Before taking metronidazole,

• tell your doctor or pharmacist if you are allergic to this medication, any part of this medication, or any other medications, foods or substances. Tell your doctor or pharmacist about the allergy and what symptoms you had.
• tell your doctor or pharmacist if you are taking the following medication or have stopped taking it within the past two weeks: disulfiram.
• some medications should not be taken with metronidazole. Other medications may cause dosing changes or extra monitoring when taken with metronidazole. Make sure you have discussed any medications you are currently taking or plan to take before starting metronidazole with your doctor and pharmacist. Before starting, stopping, or changing any medications while taking metronidazole, please get the advice of your doctor or pharmacist.
• you should know that the following nonprescription or herbal products may interact with metronidazole: cimetidine. Be sure to let your doctor and pharmacist know that you are taking this medication before you start taking metronidazole. Do not start this medication while taking metronidazole without discussing with your healthcare provider.
• tell your doctor if you have or have ever had Crohn's disease, blood problems, or kidney or liver disease. Also, tell your doctor if you have a yeast infection or a medical condition that affects your brain.
• tell your doctor if you are pregnant or plan to become pregnant. If you become pregnant while taking metronidazole, call your doctor. Women who are pregnant generally should not take metronidazole during the first trimester (first 3 months) of pregnancy.
• tell your doctor if you are breastfeeding or plan to breastfeed. If you take metronidazole while you are breastfeeding, your baby may receive some metronidazole in breast milk. If you are breastfeeding, your doctor may tell you to pump and discard your milk while you are taking metronidazole and for 48 hours after your final dose. Talk to your doctor about the best way to feed your baby while you are taking metronidazole.
• tell your doctor if you or your child has Cockayne syndrome (a serious genetic disorder). Your doctor will probably tell you that you or your child should not take metronidazole.
• do not drink alcoholic beverages or take products with alcohol or propylene glycol while taking this medication and for at least 3 days after your final dose. Alcohol and propylene glycol may cause nausea, vomiting, stomach cramps, headache, sweating, and flushing (redness of the face) when taken with metronidazole.

What should I do if I forget to take a dose?

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What should I do in case of overdose?

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help . If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Symptoms of overdose may include the following:

• nausea, vomiting
• loss of muscle coordination; seizures
• numbness, pain, burning, or tingling in your hands or feet

What side effects can this medicine cause?

Metronidazole may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• vomiting, nausea, diarrhea; upset stomach; stomach cramps; constipation
• loss of appetite
• headache
• dry mouth
• furry tongue; mouth or tongue irritation; sharp, unpleasant metallic taste

Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately:

• numbness, pain, burning, or tingling in your hands or feet
• seizures; problems with coordination; confusion; dizziness
• rash, itching, hives; flushing
• peeling or blistering skin; blisters or sores in your mouth; redness or swelling of your face, hands, or soles of your feet; muscle or joint aches
• stuffy nose, fever, sore throat, or other signs of infection
• difficulty speaking

Metronidazole may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online ( https://www.fda.gov/Safety/MedWatch ) or by phone ( 1-800-332-1088).

What should I know about storage and disposal of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from light, excess heat and moisture (not in the bathroom).

Keep all medication out of sight and reach of children as many containers are not child-resistant. Always lock safety caps. Place the medication in a safe location – one that is up and away and out of their sight and reach. https://www.upandaway.org Dispose of unneeded medications in a way so that pets, children, and other people cannot take them. Do not flush this medication down the toilet. Use a medicine take-back program. Talk to your pharmacist about take-back programs in your community. Visit the FDA's Safe Disposal of Medicines website https://goo.gl/c4Rm4p for more information.

What other information should I know?

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to metronidazole.

Before having any laboratory test, tell your doctor and the laboratory personnel that you are taking metronidazole.

Do not let anyone else take your medication. Your prescription is probably not refillable. If you still have symptoms of infection after you finish the metronidazole, call your doctor.

Keep a written list of all of the prescription and nonprescription (over-the-counter) medicines, vitamins, minerals, and dietary supplements you are taking. Bring this list with you each time you visit a doctor or if you are admitted to the hospital. You should carry the list with you in case of emergencies.