Metronidazole (met-ro(h)-nide-ah-zole) 200 & 400 mg tablets
Consumer Medicine Information (CMI)
What is in this leaflet
This leaflet answers some common questions about Metronide.
It does not contain all the available information. It does not take the place of talking to your doctor or pharmacist.
All medicines have risks and benefits. Your doctor has weighed the risks of you taking Metronide against the expected benefits they expect it will have for you.
If you have any concerns about taking this medicine, ask your doctor or pharmacist.
Keep this leaflet with the medicine.
You may need to read it again.
What Metronide is used for
Metronide is used to treat certain infections caused by bacteria and other organisms in different parts of the body.
It is also used to prevent or treat certain infections that may occur during surgery.
Metronide is an antibiotic that belongs to a group of medicines called nitroimidazoles.
This medicine works by killing or stopping the growth of bacteria and other organisms causing these infections.
Your doctor may have prescribed Metronide for another reason.
Ask your doctor if you have any questions about why Metronide has been prescribed for you.
This medicine is available only with a doctor's prescription.
There is no evidence that this medicine is addictive.
Before you take Metronide
When you must not take it
Do not take Metronide if you have ever had an allergic reaction to:
Metronide or any other nitroimidazoles
any of the ingredients listed at the end of this leaflet
Some symptoms of an allergic reaction include skin rash, itching, shortness of breath or swelling of the face, lips or tongue, which may cause difficulty in swallowing or breathing.
Do not take/use Metronide if
you have evidence of, or have a history of, a blood disorder
you have, or have ever had, a disease of the brain, spinal cord or nerves
the expiry date on the pack has passed
If you take this medicine after the expiry date has passed, it may have no effect at all, or worse, an entirely different effect.
the packaging is torn or shows signs of tampering
If you are not sure whether to start taking Metronide, talk to your doctor.
Before you start to take it
You must tell your doctor if you have any allergies to any other medicines or any other substances such as foods, preservatives or dyes.
Tell your doctor if you have or have ever had any health problems/ medical conditions including:
a blood disorder
disease of the brain, spinal cord or nerves
liver or kidney disease
an inflammatory disease of the small intestine (e.g. Crohn's disease).
you drink alcohol
Do not drink alcohol during (and for 24 hours after stopping) treatment with Metronide.
you plan to become pregnant or breastfeed
If you have not told your doctor or pharmacist about any of the above, tell them before you start taking Metronide.
Taking other medicines
Tell your doctor if you are taking any other medicines, including medicines you buy without prescription from a pharmacy, supermarket or health food shop.
Some medicines may be affected by Metronide or may affect how well it works. These include:
warfarin or other medicines used to prevent blood clots
Antabuse(R) (disulfiram), a medicine used to treat chronic alcohol dependence
some anticancer drugs, such as carmustine, cyclophosphamide, 5-fluorouracil or busulfan
phenytoin, a drug used to treat convulsions
phenobarbitone, a medicine for convulsions or sedation
cimetidine, a medicine used to treat gastric reflux and ulcers
lithium, a medicine used to treat manic depressive illness and some other types of depression
cyclosporin, a medicine used to prevent organ transplant rejection or to treat immune responses
medications containing alcohol (ethanol), e.g. some cough syrups
You may need different amounts of your medicine or you may need to take different medicines. Your doctor will advise you.
Your doctor and pharmacist may have more information on medicines to be careful with or avoid while taking Metronide.
How to take Metronide
Follow all directions given to you by your doctor and pharmacist carefully.
They may differ from the information contained in this leaflet.
If you do not understand the instructions on the box ask your doctor or pharmacist for help.
How much to take
The dose will vary from patient to patient. Your doctor will decide the right dose for you.
How to take Metronide tablets
Swallow Metronide tablets whole with a glass of water, preferably during or after a meal.
Do not chew the tablets.
This may help reduce the possibility of stomach upset.
How long to take it
For treating infection, Metronide tablets are usually taken for 7 days, however, your doctor may decide to reduce or extend your treatment. Your doctor will tell you how much Metronide to take.
Do not stop taking your tablets if you feel better.
If you do not complete the full course prescribed by your doctor, all of the bacteria/organisms causing your infection may not be killed. These bacteria/organisms may continue to grow and multiply so that your infection may not clear completely or may return.
If you forget to take it
If you are taking more than a single dose of Metronide, and it is almost time for your next dose, skip the dose you missed and take your next dose when you are meant to. Otherwise, take it as soon as you remember, then go back to taking it as you would normally.
Do not take a double dose to make up for the dose you missed.
If you have trouble remembering to take Metronide, ask your pharmacist for some hints.
If you take too much (overdose)
Immediately telephone your doctor or Poisons Information Centre (telephone 131126) or go to Accident and Emergency at your nearest hospital if you think that you, or anyone else, has taken too much Metronide, even if there are no signs of discomfort or poisoning.
You may need urgent medical attention.
If you take too many tablets you may experience vomiting and a feeling of disorientation.
While you are taking Metronide
Things you must do
Tell your doctor immediately if:
the symptoms of your infection do not improve or become worse
you become pregnant
you are about to start taking any new medicines.
If you get a sore, white mouth or tongue while taking or soon after stopping Metronide treatment, tell your doctor. Also tell your doctor if you get vaginal itching or discharge.
This may mean you have a fungal/yeast infection called thrush. Sometimes the use of Metronide allows fungi/yeast to grow and the above symptoms to occur. Metronide does not work against fungi/yeast.
If you are taking Metronide for 10 days or longer, make sure you have any tests of your blood and nervous system that your doctor may request.
If you need to have a blood test while taking Metronide, tell your doctor as Metronide may affect the results of some laboratory tests.
Tell all doctors, dentists and pharmacists who are treating you that you are taking Metronide.
Things you must not do
Do not drink alcohol or consume any medication containing alcohol while taking Metronide and for at least one day after finishing treatment.
The use of alcohol may make you feel very sick, vomit, have stomach cramps, headaches and flushing.
Do not stop taking your medicine because you are feeling better, unless advised by your doctor.
If you do not take all of the medicine prescribed by your doctor, all of the bacteria/organisms causing your infection may not be killed. These bacteria/organisms may continue to grow and multiply so that your infection may not clear completely or may return.
Do not give Metronide to anyone else, even if they have the same condition as you.
Do not use Metronide to treat any other medical complaints unless your doctor tells you to.
Things to be careful of
Be careful driving or operating machinery until you know how Metronide affects you.
Tell your doctor as soon as possible if you have any problems while taking Metronide, even if you do not think the problem is connected with the medicine or is not listed in this leaflet.
As with most medications, Metronide can sometimes cause unwanted side effects. If they occur, most are likely to be minor and temporary. However, some may be serious and need medical attention.
Ask your doctor or pharmacist to answer any questions you may have.
Tell your doctor or pharmacist if you notice any of the following and they worry you:
oral thrush - white, furry, sore or inflamed tongue and mouth
vaginal thrush - sore and itchy vagina and/or discharge
nausea, which may be accompanied by headache, loss of appetite, and vomiting
diarrhoea, stomach discomfort, abdominal cramping or constipation, strange taste in mouth
convulsions, dizziness, weakness, feeling of incoordination or uncoordinated movements
confusion, irritability, depression or sleeplessness
skin rashes, flushing, itching
stuffy nose, dry mouth, nasal congestion, dryness of the mouth (or vagina or vulva)
unusual urination patterns (e.g. difficulty in passing urine, large amounts of urine, incontinence, or pus in urine)
eye problems, including blurred or double vision
yellowing of the skin or eyes, which may be jaundice
If you have been on prolonged Metronide therapy, and experience any unusual numbness of the feet or hands, stop taking Metronide, and tell your doctor immediately.
Other side effects not listed above may also occur in some patients.
Tell your doctor as soon as possible if you notice any other effects.
Do not be alarmed by this list of possible side effects.
You may not experience any of them.
After taking Metronide
Keep Metronide tablets in the blister pack until it is time to take them.
If you take the tablets out of the blister pack, they may not keep well.
Keep Metronide tablets in a cool dry place where the temperature stays below 30°C.
Do not store them or any other medicine in the bathroom or near a sink.
Do not leave your medicine in the car or on windowsills.
Heat and dampness can destroy some medicines.
Keep your medicine where children cannot reach it.
A locked cupboard at least one-and-a-half metres above the ground is a good place to store medicines.
If your doctor tells you to stop taking Metronide, or the medicines have passed their expiry date, ask your pharmacist what to do with any medicine that is left over.
What it looks like
Metronide tablets come in two strengths:
Metronide 200 mg -: round, white, with a breakline, marked "MTZ 200" on one side. A box contains 21 tablets
Metronide 400 mg -: round, white, with a breakline, marked "MTZ 400" on one side. A box contains 21 tablets
Metronide 200 - 200 mg metronidazole/tablet
Metronide 400 - 400 mg metronidazole/tablet
Metronide 200 mg and 400 mg tablets also contain calcium hydrogen phosphate, maize starch, povidone, macrogol 400, hypromellose, magnesium stearate and purified talc (400 mg only).