How does this medication work? What will it do for me?
Metronidazole belongs to the class of medications called antibiotics. It is used to treat infections caused by certain bacteria. It is most commonly used for abdominal, vaginal, and intestinal infections. Metronidazole works by killing bacteria and parasites.
This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.
Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.
Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.
What form(s) does this medication come in?
Each white, round biconvex film coated tablet, engraved with "250" on one side and plain on the other contains metronidazole 250mg. Nonmedicinal ingredients: croscarmellose sodium, colloidal silicon dioxide, microcrystalline cellulose, and magnesium stearate.
Each pale green and light grey capsule embossed with "500" contains metronidazole 500 mg. Nonmedicinal ingredients: croscarmellose sodium, colloidal silicon dioxide, and stearic acid. Capsule shell: gelatin, D&C red No. 33, D&C yellow No. 10, FD&C Blue No. 11, FD&C green No. 3, talc, and titanium dioxide. Edible ink contains: black iron oxide, shellac glaze, propylene glycol, FD&C blue No. 2, FD&C red No. 40.
How should I use this medication?
The dose of metronidazole depends on the condition being treated. The usual adult dose of metronidazole is 500 mg taken by mouth every 8 hours or twice daily. For treatment of trichomoniasis, a single dose of 2,000 mg may be taken orally after a meal. Many other doses exist according to the infection being treated.
Metronidazole may be taken with or without food. If it causes stomach upset, it is best taken with food or milk.
Metronidazole vaginal cream or gel is used for vaginal infections. The dose is applied into the vagina usually once or twice a day. See the package insert or talk to your health care provider about how to use the applicator correctly.
Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones given here, do not change the way that you are taking the medication without consulting your doctor.
It is important to take this medication regularly and exactly as prescribed by the doctor. Keep taking this medication until the prescription is complete even if you feel better. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.
Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.
Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.
Who should NOT take this medication?
Do not take this medication if you:
- are allergic to metronidazole or any ingredients of the medication
- have a history of blood disorders
- have a brain (neurological) disorder
- have an underactive thyroid (hypothyroidism)
- have underactive adrenal glands (hypoadreanalism)
What side effects are possible with this medication?
Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.
The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.
- change in taste sensation
- darker urine
- dizziness or lightheadedness
- dryness of mouth
- loss of appetite
- stomach pain or cramps
- unpleasant or sharp metallic taste
Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.Check with your doctor as soon as possible if any of the following side effects occur:
- any vaginal irritation, discharge, or dryness not present before use of this medicine
- fever or unexpected infections
- mood or other mental changes
- skin rash, redness, or itching
- vision changes
Stop taking the medication and seek immediate medical attention if any of the following occur:
- convulsions (seizures)
- difficulty coordinating body movement
- extreme sensitivity to bright light
- numbness, tingling, pain, or weakness in hands or feet
- signs of a serious allergic reaction ( e.g.,difficulty breathing, itchyskin rash, swelling of face or throat, wheezing)
- signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
- stiff neck along with a headache
Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.
Are there any other precautions or warnings for this medication?
Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.
Alcohol: A severe set of side effects including nausea, vomiting, and rapid heartbeat may occur if you drink alcohol while taking metronidazole. If you are taking this medication, wait until at least one day after finishing metronidazole treatment before drinking alcohol.
Blood cell counts: This medication may cause low white blood cell counts, which can mean your immune system is weak. If you develop a fever, talk to your doctor as soon as possible. Your doctor may also perform blood tests regularly to monitor your blood cell counts if you are taking this medication for a long period of time.
Confusion/dizziness: This medication may cause confusion or dizziness. Avoid driving or other tasks requiring alertness if the medication affects you in this way.
Diarrhea: If diarrhea occurs while taking metronidazole,contact your doctor.
Liver disease:. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Your doctor may want to test your liver function regularly with blood tests while you are taking this medication.
Neurological side effects: Stop treatment with metronidazole and see your doctor if muscle incoordination, seizures, or numbness or tingling in the hands or feet occur.
Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding: Metronidazole passes into breast milk. It should not be taken by women who are breast-feeding.
Children: The safety and effectiveness of using this medication have not been established for children.
What other drugs could interact with this medication?
There may be an interaction between metronidazole and any of the following:
If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:
- stop taking one of the medications,
- change one of the medications to another,
- change how you are taking one or both of the medications, or
- leave everything as is.
An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.
Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.