Skip to Content


Active substance(s): METRONIDAZOLE

View full screen / Print PDF » Download PDF ⇩
Metronidazole 200mg
and 400mg Tablets
Read all of this leaflet carefully before you
start taking this medicine.
• K eep this leaflet. You may need to read
it again.
• If you have any further questions, 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.

 hat Metronidazole tablets are
1 W
and what they are used for
2 Before you take
3 How to take
4 Possible side effects
5 How to store
6 Further information
 hat Metronidazole tablets are and what
1 W
they are used for

Metronidazole tablets belong to a group of medicines
called anti-infective agents. They may be used to treat:
• infections, caused by bacteria of the blood, brain, bone,
lung, stomach lining and pelvic area, following childbirth
or in a wound following an operation
• u rinary or genital infections caused by a parasite,
• genital infection in women caused by bacteria
• the parasitic diseases amoebiasis
• the disease giardiasis
• gum and teeth infections
• infected leg ulcers or pressure sores
• stomach ulcers caused by Helicobacter pylori.
• or prevent infections occurring after operations.

2 Before you take

Do not take Metronidazole tablets and tell your
doctor if you:

• are allergic (hypersensitive) to Metronidazole tablets or
any of the other ingredients (see section 6)
• a re in the first 3 months of pregnancy or are

Check with your doctor or pharmacist before
taking Metronidazole tablets if you:

• have kidney disease, particularly if you require dialysis
• are or have ever suffered from any liver disease
• are in the 4th-9th month of pregnancy
• have epilepsy or have ever had fits
• have porphyria (a genetic disease that can cause skin
blisters, abdominal pain and brain/nervous system
• have any disorder of the blood and/or blood cells
• have any nervous system disorders
• h ave been exposed to any sexually transmitted disease.

130x210 Leaflet Reel Fed Profile (BST)

Taking other medicines

Please tell your doctor or pharmacist if you are taking
or have recently taken any other medicines, including
medicines obtained without a prescription. Especially:
 edicines to stop the blood clotting such as warfarin
• lithium (used to treat depression)
 edicines to treat epilepsy such as phenobarbital,
phenytoin, primidone
• disulfiram (to treat alcohol addiction)
• ciclosporin (used following organ transplants)
• fluorouracil (used to treat some forms of cancer)
• cimetidine (used to treat stomach ulcers)
• oestrogen contraceptives (‘the pill’).

Pregnancy and breastfeeding

Metronidazole tablets must not be taken during the first 3
months of pregnancy and should not be taken during the
rest of the pregnancy.
If you breastfeed you should stop whilst taking
Metronidazole tablets and for 12-24 hours after the
course of tablets has finished before breastfeeding again.
Ask your doctor or pharmacist for advice before taking this

Driving and using machines

Metronidazole tablets may make you feel drowsy, dizzy,
confused or affect your vision, cause fits or hallucinations.
Make sure you are not affected before you drive, operate
machinery or take part in any activities where these may
put you or others at risk.

Sugar intolerance

If you have been told you have an intolerance to some
sugars, contact your doctor before taking this medicine, as
it contains a sugar called lactose.


If you are taking this medicine for more than 10 days, your
doctor may wish to carry out further tests.
If you need any blood or urine tests, tell your doctor you are
taking Metronidazole tablets before the test.

3 How to take

Always take Metronidazole tablets exactly as your doctor
has told you. If you are not sure, check with your doctor or
You are advised not to drink alcohol whilst taking this
medicine and for 48 hours after finishing the course of
tablets, as this might cause unpleasant side-effects, such as
feeling or being sick, stomach pain, hot flushes, palpitations
and headache.
Swallow the tablets whole, during or after meals, with a
glass of water. Do not chew them.
• T reatment of bacterial infections
Adults and children over 10 years: 800mg followed by
400mg at eight hourly intervals. Treatment is usually for 7
days but will depend upon your condition.
• Treatment of anaerobic infections
Children 8 weeks-12 years: 20-30mg/kg/day as a single
dose or divided into 7.5mg/kg every 8 hours for 7 days.
Children under 8 weeks: 15mg/kg/day as a single dose or
divided into 7.5mg/kg every 12 hours.

• Treatment of infection caused by Trichomonas
Adults and adolescents: 2g as a single dose, or 200mg three
times a day for 7 days, or 400mg twice a day for 5 to 7 days. Your
partner should also be treated.
Children under 10 years: 40mg/kg as a single dose or 15-30mg/
kg/day two to three times daily for 7 days.
• Treatment of non-specific genital infection in women
Women: 400mg twice a day for 7 days, or 2g as a single dose for
1 day only.
Adolescent girls: 400mg twice daily for 5 to 7 days or 2g as a
single dose.
• Treatment of amoebiasis
Adults and children over 10 years: 400mg-800mg three times a
day for 5 to 10 days.
Children 7-10 years: 200mg-400mg three times a day for 5 to 10
Children 3 -7 years: 100mg-200mg four times daily for
5 to 10 days.
Children 1 -3 years: 100mg-200mg three times daily for 5 to 10
Or 35-50mg/kg/day in 3 divided doses for 5 to 10 days.
• Treatment of giardiasis
Adults and children over 10 years: 2g once a day for
3 days, or 400mg three times a day for 5 days or 500mg twice
daily for 7 to 10 days.
Children 7-10 years: 1g once a day for 3 days.
Children 3 - 7 years – 600mg-800mg once daily for
3 days.
Children 1-3 years: 500mg once daily for 3 days.
Or 15-40mg/kg/day divided in two to three doses.
• Treatment of infections of the gums (for 3 days) or teeth
(for 3-7 days)
Adults and children over 10 years: 200mg three times a day.
• Treatment of infected leg ulcers or pressure sores (for 7
Adults and children over 10 years: 400mg three times a day
• Treatment of stomach ulcers caused by Helicobacter pylori
To be taken as directed by your doctor as part of a course with
two other medicines.
• Prevention of infections after surgery
Adults: 1g as a single dose 24 hours before surgery then,
400mg at 8 hourly intervals during the 24 hours before the
Children under 12 years: 20-30mg/kg as a single dose 1-2 hours
before the operation.
Newborns with a gestation age less than 40 weeks:
A more suitable dosage form should be used.
If you are elderly or have liver disease, it is particularly important
to take this medicine exactly as directed by the doctor.

If you take more than you should

If you (or someone else) swallow a lot of tablets at the same
time, or you think a child may have swallowed any contact
your nearest hospital casualty department or tell your doctor
immediately. Signs of an overdose include feeling or being sick,
loss of appetite, diarrhoea, metallic taste, headache, dizziness,
insomnia or drowsiness.

If you forget to take the tablets

Do not take a double dose to make up for a forgotten dose. If
you forget to take a dose take it as soon as you remember it and
then take the next dose at the right time.

If you stop taking the tablets

If you stop taking the tablets your infection may come back. Talk
to your doctor before you stop taking the tablets and follow
their advice.

4 Possible side effects

Like all medicines, Metronidazole tablets can cause side
effects, particularly when you first start taking it, although not
everybody gets them.
Please tell your doctor or pharmacist if you notice any of the
following effects or any effects not listed.
Contact your doctor at once if you notice any of the following
side effects:
 llergic reactions: skin rash, which may be itchy, swelling of
the face, lips, tongue or throat, fever or difficulty in breathing.

AAAH2618 50824884

130x210 Leaflet Reel Fed Profile (BST)

Tell your doctor if you notice any of the following side effects or
notice any other effects not listed:
Very rare (less than 1 in 10,000 users):
• increased bruising, nosebleeds, sore throats or infections, this
medicine may alter the numbers and types of your blood cells.
You should tell your doctor who might want you to have a
blood test
• mental health problems including hallucinations (seeing or
hearing things that are not there), drowsiness, dizziness, fits,
tingling, pain or a feeling of weakness in the arms or legs,
• encephalopathy (headaches, light sensitivity, confusion, fever,
paralysis, stiff neck)
• cerebellar syndrome (poor co-ordination or muscle control,
involuntary shakiness, uncontrolled eye movements, speech
disorders, walking abnormally)
• double vision, short sightedness
• change in liver function tests, jaundice (yellowing of the skin or
whites of the eyes), inflammation of the pancreas (pancreatitis
causing very severe abdominal pain), flushing
• skin rashes, itching, small pus-containing blisters, muscles and
joint pain, darkening of the urine
Not known (cannot be estimated from the available data):
• bone marrow depression disorders such as aplastic anaemia
(causing weakness, bruising, making infections more likely)
• Urticaria (itchy, pale or red irregular raised patches of skin), fever
• depression, ‘pins and needles’
• unpleasant taste in the mouth, changes in taste, furred tongue,
mouth ulcers, feeling or being sick, loss of appetite, diarrhoea,
stomach pain and upset stomach
• erythema multiforme (circular, irregular red patches)
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.

5 How to store

Keep out of the reach and sight of children.
Store below 25°C in a dry place.
Do not use Metronidazole tablets after the expiry date stated on
the label/carton/bottle. The expiry date refers to the
last day of that month.
Medicines should not be disposed of via
wastewater or household waste. Ask your
pharmacist how to dispose of medicines no longer
required. These measures will help to protect the

6 Further information

What Metronidazole tablets contain

• T he active substance (the ingredient that makes
the tablets work) is metronidazole.
• The other ingredients are croscarmellose sodium,
cellulose, colloidal silica, lactose, magnesium
stearate, maize starch, polyethylene glycol,
titanium dioxide (E171), hydroxypropylcellulose
(E463), methylhydroxypropylcellulose (E464).

What Metronidazole tablets look like and
contents of the pack
Metronidazole 200mg tablets are white,
film-coated tablets.
Metronidazole 400mg tablets are white, capsule
shaped, biconvex, film-coated tablets.
Pack sizes are 21 tablets
Marketing Authorisation Holder and Manufacturer
Actavis, Barnstaple, EX32 8NS, UK.
Date of last revision:
October 2014

Expand view ⇕

Source: Medicines and Healthcare Products Regulatory Agency

Disclaimer: Every effort has been made to ensure that the information provided here is accurate, up-to-date and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. This information has been compiled for use by healthcare practitioners and consumers in the United States. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate that the drug or combination is safe, effective or appropriate for any given patient. If you have questions about the substances you are taking, check with your doctor, nurse or pharmacist.