METRONIDAZOLE (me troe NI da zole) treats infections caused by bacteria or parasites. It belongs to a group of medications called antibiotics. It will not treat colds, the flu, or infections caused by viruses.
What should I tell my care team before I take this medication?
They need to know if you have any of these conditions:
History of blood diseases, such as sickle cell anemia, anemia, or leukemia
Frequently drink alcohol
Irregular heartbeat or rhythm
Yeast or fungal infection
An unusual or allergic reaction to metronidazole, other medications, foods, dyes, or preservatives
Pregnant or trying to get pregnant
How should I use this medication?
Take this medication by mouth with water. Take it as directed on the prescription label at the same time every day. Take all of this medication unless your care team tells you to stop it early. Keep taking it even if you think you are better.
Talk to your care team about the use of this medication in children. While it may be prescribed for children for selected conditions, precautions do apply.
What if I miss a dose?
If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.
What may interact with this medication?
Do not take this medication with any of the following:
Alcohol or any product containing alcohol
This medication may also interact with the following:
Certain medications that treat or prevent blood clots, such as warfarin
Estrogen or progestin hormones
Other medications that cause heart rhythm changes
What side effects may I notice from receiving this medication?
Side effects that you should report to your care team as soon as possible:
Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
Dizziness, loss of balance or coordination, confusion or trouble speaking
Fever, neck pain or stiffness, sensitivity to light, headache, nausea, vomiting, confusion
Heart rhythm changes—fast or irregular heartbeat, dizziness, feeling faint or lightheaded, chest pain, trouble breathing
Liver injury—right upper belly pain, loss of appetite, nausea, light-colored stool, dark yellow or brown urine, yellowing skin or eyes, unusual weakness or fatigue
Pain, tingling, or numbness in the hands or feet
Redness, blistering, peeling, or loosening of the skin, including inside the mouth
Severe diarrhea, fever
Sudden eye pain or change in vision such as blurry vision, seeing halos around lights, vision loss
Unusual vaginal discharge, itching, or odor
Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):
Metallic taste in mouth
What should I watch for while using this medication?
Visit your care team for regular checks on your progress. Tell your care team if your symptoms do not start to get better or if they get worse.
Some products may contain alcohol. Ask your care team if this medication contains alcohol. Be sure to tell all care teams you are taking this medication. Certain medications, such as metronidazole and disulfiram, can cause an unpleasant reaction when taken with alcohol. The reaction includes flushing, headache, nausea, vomiting, sweating, and increased thirst. The reaction can last from 30 minutes to several hours.
If you are being treated for a sexually transmitted infection (STI), avoid sexual contact until you have finished your treatment. Your partner may also need treatment.
Estrogen and progestin hormones may not work as well while you are taking this medication. A barrier contraceptive, such as a condom or diaphragm, is recommended if you are using these hormones for contraception. Talk to your care team about effective forms of contraception.
Where should I keep my medication?
Keep out of the reach of children and pets.
Store between 15 and 25 degrees C (59 and 77 degrees F). Protect from light. Get rid of any unused medication after the expiration date.
To get rid of medications that are no longer needed or have expired:
Take the medication to a medication take-back program. Check with your pharmacy or law enforcement to find a location.
If you cannot return the medication, check the label or package insert to see if the medication should be thrown out in the garbage or flushed down the toilet. If you are not sure, ask your care team. If it is safe to put it in the trash, take the medication out of the container. Mix the medication with cat litter, dirt, coffee grounds, or other unwanted substance. Seal the mixture in a bag or container. Put it in the trash.
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.
This information is educational only and should not be construed as specific instructions for individual patients nor as a substitute for medical advice, diagnosis or treatment. Talk to your health care provider or pharmacist about the information and instructions. K Health assumes no liability for any use or reliance on this information.