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Active substance(s): METRONIDAZOLE

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Metronidazole Benzoate
Read all of this leaflet carefully before you start taking this medicine.
 Keep this leaflet. You may need to read it again.
 If you have further questions, please ask your doctor or pharmacist.
 This medicine has been prescribed for you. Do not pass it on to others. It may harm them, even if their
symptoms are the same as yours.
 If any of the side effects gets serious, or if you notice any side effects not listed in this leaflet, please tell
your doctor or pharmacist.
In this leaflet:
1. What Flagyl is and what it is used for
2. Before you take Flagyl
3. How to take Flagyl
4. Possible side effects
5. How to store Flagyl
6. Further information


What Flagyl is and what it is used for

The name of this medicine is Flagyl S 200mg/5ml Oral Suspension (called Flagyl in this leaflet). Flagyl
contains a medicine called metronidazole benzoate. This belongs to a group of medicines called antibiotics.
It works by killing bacteria and parasites that cause infections in your body.
It can be used to:
 Treat infections of the blood, brain, lung, bones, genital tract, pelvic area, stomach and intestines
 Treat gum ulcers and other dental infections
 Treat infected leg ulcers and pressure sores
 Prevent infections after surgery
If you need any further information on your illness, speak to your doctor.


Before you take Flagyl

Do not take Flagyl and tell your doctor if:
 You are allergic (hypersensitive) to metronidazole, nitroimidazoles (e.g. tinidazole) or any of the other
ingredients in your medicine (listed in Section 6: Further information).
Signs of an allergic reaction include: a rash, swallowing or breathing problems, swelling of your lips, face,
throat or tongue.
Do not take Flagyl if any of the above apply to you. If you are not sure, talk to your doctor or pharmacist
before taking Flagyl.
Take special care with Flagyl and check with your doctor or pharmacist before using your medicine if:
 You have or have ever had a liver problem.
 You are having kidney dialysis (see section 3: ‘People having kidney dialysis’)
 You have a disease of the nervous system
If you are not sure if any of the above apply to you, talk to your doctor or pharmacist before taking your
medicine. Do this even if they have applied in the past.

Cases of severe liver toxicity/acute liver failure, including cases with a fatal outcome, in patients with
Cockayne syndrome have been reported with Flagyl.

If you are affected by Cockayne syndrome, your doctor should also monitor your liver function
frequently while you are being treated with Flagyl and afterwards.
Tell your doctor immediately and stop taking Flagyl if you develop:

Stomach pain, anorexia, nausea, vomiting, fever, malaise, fatigue, jaundice, dark urine,
putty or mastic coloured stools or itching.
Taking other medicines
Please tell your doctor or pharmacist if you are taking or have recently taken any other medicines. This
includes medicines obtained without a prescription, including herbal medicines. This is because Flagyl can
affect the way some other medicines work. Also, some other medicines can affect the way Flagyl works.
In particular tell your doctor if you are taking any of the following medicines:
 Medicines used to thin the blood such as warfarin
 Lithium for mental illness
 Phenobarbital or phenytoin for epilepsy
 5 fluorouracil for cancer
 Busulfan for leukaemia (cancer of the blood cells)
 Ciclosporin – to prevent the rejection of organs after transplant
 Disulfiram for alcoholism
If you are not sure, talk to your doctor or pharmacist before taking Flagyl.
Taking Flagyl with food and drink
Do not drink any alcohol while you are taking Flagyl and for 48 hours after finishing your course. Drinking
alcohol while using Flagyl might cause unpleasant side effects, such as feeling sick (nausea), being sick
(vomiting), stomach pain, hot flushes, very fast or uneven heartbeat (palpitations) and headache.
Pregnancy and breast-feeding
Tell your doctor before using Flagyl if:
 You are pregnant, might become pregnant or think you may be pregnant. Flagyl should not be taken during
pregnancy unless considered absolutely necessary.
 You are breast-feeding. It is better not to use Flagyl if you are breast-feeding. This is because small
amounts may pass into the mother’s milk.
Driving and using machines
While taking Flagyl you may feel sleepy, dizzy, confused, see or hear things that are not there (hallucinations),
have fits (convulsions) or temporary eyesight problems (such as blurred or double vision). If this happens, do
not drive or use any machinery or tools.
Your doctor may wish to carry out some tests if you have been using this medicine for more than 10 days.
Important information about some of the ingredients of your medicine
 Sucrose: This is a type of sugar. If you have been told by you doctor that you cannot tolerate some sugars,
talk to your doctor before taking this medicine.
 Methyl hydroxybenzoate (E218) and propyl hydroxybenzoate (E216): These are preservatives that are
added to Flagyl to make the medicine last longer. These can cause an allergic reaction in some people.
 Alcohol: Flagyl contains 0.8% alcohol (ethanol) by volume; this is equivalent to 32mg alcohol per 5ml
dose. At high doses this could be harmful for those suffering from alcoholism, liver disease or epilepsy.


How to take Flagyl

Taking your medicine
Always take Flagyl exactly as your doctor has told you. It is important to finish a full course of treatment. The
length of a course will depend on your needs and the illness being treated.
Check with your doctor or pharmacist if you are not sure.
 Take Flagyl Suspension by mouth

The dose of Flagyl will depend on your needs and the illness being treated
The length of your treatment will depend on the type of illness you have and how bad it is
Your doctor or pharmacist may dilute your Flagyl Suspension. In this case the pharmacist’s label on the
packaging will tell you how exactly much to take and how often.

The usual dose for adults and children is given below:
To treat certain bacterial infection
Adults and children over 10 years
 Take 10ml (400mg) of Flagyl Suspension once every 8 hours
Children and infants
 Your doctor will work out how much your child should take depending on their weight
 Repeat the dose every 8 hours
 If your child is a baby under 8 weeks of age, your doctor will give them one daily dose or two separate
doses 12 hourly
To prevent infections from happening after surgery
 Give your child Flagyl suspension 2-3 hours before their operation
 Your doctor will work out how much your child should take depending on their weight
Other types of infections
For treatment of other infections caused by parasites and some bacteria your doctor will decide how much
Flagyl you need to take. This will depend on your illness and how bad it is. The pharmacist’s label on the
packaging will tell you exactly how much Flagyl Suspension to take and how often.
People having kidney dialysis
Kidney dialysis removes Flagyl from your blood. If you are having kidney dialysis you must take this
medicine after your dialysis treatment.
People with liver problems
Your doctor may tell you to use a lower dose or to use the medicine less often.
If you take more Flagyl than you should
If you take more Flagyl than you should, tell your doctor or go to your nearest hospital casualty department
straight away. Take the carton and bottle with you. This is so the doctor knows what you have taken.
If you forget to take Flagyl
If you forget to take Flagyl, take it as soon as you remember. However, if it is almost time for your next dose,
skip the missed dose. Do not use a double dose to make up for a forgotten dose.


Possible side effects

Like all medicines, Flagyl can cause side effects, although not everybody gets them.
Stop taking Flagyl and see a doctor or go to a hospital straight away if:
 You get swelling of the hands, feet, ankles, face, lips or throat which may cause difficulty in swallowing or
breathing. You could also notice an itchy, lumpy rash (hives) or nettle rash (urticaria)
This may mean you are having an allergic reaction to Flagyl.
 A serious but very rare side effect is a brain disease (encephalopathy). Symptoms vary but you might get a
fever, stiff neck, headache, see or hear things that aren’t there. You might also have problems using your
arms and legs, problems with speaking or feel confused.
 You develop skin rashes with blistering, peeling or bleeding of the skin around the lips, eyes, mouth, nose
and genitals. You may also have flu-like symptoms and a high temperature. These could be signs of
something called ‘Stevens Johnson Syndrome or toxic epidermal necrolysis’.
Talk to your doctor straight away if you notice the following side effects.

Yellowing of the skin and eyes. This could be due to a liver problem (jaundice).

Unexpected infections, mouth ulcers, bruising, bleeding gums, or severe tiredness. This could be caused
by a blood problem.
Severe stomach pain which may reach through to your back (pancreatitis)

Tell your doctor or pharmacist if you notice any of the following side effects:

Very rare (affects less than 1 in 10 000 people)

Fits (convulsions)
Mental problems such as feeling confused and seeing or hearing things that are not there (hallucinations)
Problems with your eyesight such as blurred or double vision
Skin rash or flushing
Darkening of the urine
Feeling sleepy or dizzy
Pains in the muscles or joints
Liver problems including life-threatening liver failure (hepatocellular liver injury)

Not known (frequency cannot be estimated from the available data)

Numbness, tingling, pain, or a feeling of weakness, in the arms or legs

Unpleasant taste in the mouth

Furred tongue

Feeling sick (nausea), being sick (vomiting), upset stomach, stomach pain or diarrhoea

Loss of appetite


Feeling depressed

Pain in your eyes (optic neuritis)

A group of symptoms together including: fever, nausea, vomiting, headache, stiff neck and extreme
sensitivity to bright light. This may be caused by an inflammation of the membranes that cover the brain
and spinal cord (meningitis)

Hearing impairment/hearing loss

Ringing in the ears (tinnitus)

You get a rash or skin discolouration with or without raised areas which often reoccurs at the same
location each time the drug is taken
Reporting of side effects
If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not
listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme at:
By reporting side effects you can help provide more information on the safety of this medicine.



How to store Flagyl
Keep your medicine in a safe place and out of the reach and sight of children.
Store below 25°C.
Store your medicine in the original packaging in order to protect them from light.
Do not use this medicine after the expiry date shown on the bottle label and packaging.
Ask your pharmacist how to dispose of medicines no longer required. Do not dispose of medicines by
flushing down a toilet or sink or by throwing out with your normal household rubbish. This will help
protect the environment.

Further information

What Flagyl S 200mg/5ml Oral Suspension contains
Each 5 ml of suspension contains 200mg metronidazole (as benzoate) as the active substance.
Other ingredients are: Sucrose, sodium dihydrogen phosphate or sodium acid phosphate crystalline,
magnesium aluminium silicate, methyl hydroxybenzoate (E218), propyl hydroxybenzoate (E216), ethanol,
lemon flavouring, orange flavouring, purified water.

What Flagyl S 200mg/5ml Oral Suspension looks like and contents of the pack
The suspension is white to cream coloured with a slight yellow tinge and an odour of oranges and lemons. It is
available in 100ml bottles.
The Marketing Authorisation Holder is: Winthrop Pharmaceuticals, PO Box 611, Guildford, Surrey, GU1

Zentiva, One Onslow Street, Guildford, Surrey, GU1 4YS, UK
The Manufacturer is: Unither Liquid Manufacturing, 1-3 allée de la Neste, Z.I. d'en Sigal, 31770 Colomiers,
This leaflet was last updated in November 2016
“Flagyl” and “Winthrop” are registered trademarks. ©2016 Winthrop Pharmaceuticals.
“Flagyl” and “Zentiva” are registered trademarks. ©2016 Zentiva.

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Further information

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