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Active substance(s): ETHOSUXIMIDE

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Package leaflet: Information for the patient


250 mg/5 ml Syrup

Read all of this leaflet carefully
before you start taking this medicine
because it contains important
information for you.
• Keep 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 only.
Do not pass it on to others. It may harm them,
even if their signs of illness are the same as
• If you get any side effects, talk to your doctor
or pharmacist. This includes any possible side
effects not listed in this leaflet. See section 4.

What is in this leaflet

1. What Zarontin is and what it is used
2. What you need to know before you
take Zarontin
3. How to take Zarontin
4. Possible side effects
5. How to store Zarontin
6. Contents of the pack and other

1. What Zarontin is and what it is
used for
This medicine contains ethosuximide which is one
of a group of medicines called anti-epileptic drugs;
these medicines are used to treat epilepsy.
Zarontin can be used for the treatment of absence
seizures (a form of epilepsy) and may be taken with
other anti-epileptic drugs.
You should consult your doctor if you are unsure why
you have been given Zarontin 250 mg/5 ml Syrup, if
you do not feel better or if you feel worse.

2. What you need to know before
you take Zarontin
Do not take Zarontin

• if you are allergic (hypersensitive) to ethosuximide,
or any of the other ingredients in this medicine
(listed in section 6).

Warnings and precautions

Talk to your doctor or pharmacist before taking
Zarontin if you suffer from or have suffered in the
past from any of the following conditions:
• Liver disease.
• Kidney disease.
• Bruising, fever, looking pale or a severe sore
throat. These may be the first signs of a potentially
serious blood disorder, which could be fatal if not
Your doctor may take regular blood and/or urine
samples to test for these.
If you are taking anti-epileptic drugs, your doctor
will routinely assess you for depression, anxiety and
suicidality. If you are taking anti-epileptic drugs and
you feel depressed and anxious, the symptoms of
which are feeling low, loss of interest in everyday
activities, lack of energy and a general feeling of

unease, please consult your doctor.
A small number of people being treated with
anti-epileptics such as ethosuximide have had
thoughts of harming or killing themselves. If at any
time you have these thoughts, immediately contact
your doctor.

Other medicines and Zarontin

Tell your doctor or pharmacist if you are taking, have
recently taken or might take any other medicines,
including medicines obtained without a prescription.
Some medicines can affect the way Zarontin works,
or Zarontin itself can reduce the effectiveness of other
medicines taken at the same time. These include:
• Other medicines used for epilepsy (phenytoin,
sodium valproate and valproic acid).
Your doctor may need to test the amount of these
medicines in your blood to help decide if any of these
medicines are affecting your treatment.

Zarontin with food and drink

Zarontin can be taken before or after food and drink.

Pregnancy and Breast-feeding

If you are pregnant, think you may be pregnant or
are planning to have a baby, ask your doctor or
pharmacist for advice before taking this medicine.
You should not take Zarontin if you are breastfeeding.
Driving and using machines
Zarontin may cause dizziness or drowsiness. If you
experience these symptoms, do not drive or use any
tools or machinery.

Zarontin contains sucrose and

Sucrose and glucose are types of sugars. If you have
been told by your doctor that you have an intolerance
to some sugars, contact your doctor before taking
this medicinal product. This medicine may be harmful
to the teeth.


3. How to take Zarontin
Always take this medicine exactly as your doctor or
pharmacist has told you. Check with your doctor if
you are not sure.
Shake the bottle vigorously before you measure
your dose. Always use a medicine spoon or measure.
It is best to take Zarontin at the same time each day.
Zarontin can be taken before or after food and drink.

Adults and children over 6 years

The amount of Zarontin needed varies from one
person to another. Most adults and children over
6 years usually start on two 5 ml spoonfuls (500 mg)
a day and build up to four to six 5 ml spoonfuls
(1000 mg to 1500 mg) a day, with increments of
250 mg every 5 to 7 days. Occasionally eight 5 ml
spoonfuls (2000 mg) a day may be necessary.

Children under 6 years

Infants and children usually start on one 5 ml spoonful
(250 mg) a day and build up to a dose that controls
their symptoms gradually by small increments every
few days until control is achieved. The maximum dose
is four 5 ml spoonfuls (1000 mg) a day.

If you take more Zarontin than you
If you accidentally take too much Zarontin contact
your doctor at once or go to the nearest hospital
casualty department. Always take the labelled
medicine package with you, whether there is any
Zarontin left or not.

If you forget to take Zarontin

If you forget to take a dose, take it as soon as you
remember unless it is time for your next dose.
Do not take a double dose to make up for a
forgotten dose.

If you stop taking Zarontin

Do not stop taking Zarontin unless your doctor tells
you to. If you suddenly stop taking this medicine you

may have a seizure. Should you need to stop taking
Zarontin, your doctor will decide which method is
best for you.
If you have any further questions on the use of this
medicine, ask your doctor or pharmacist.

4. Possible side effects
Like all medicines, this medicine can cause side
effects, although not everybody gets them.
Tell your doctor immediately if you experience any
of the following symptoms after taking this medicine.
Although they are very rare, these symptoms can be
• If you develop a severe skin rash that causes
blistering, this can affect the mouth and tongue.
These may be signs of a condition known as
Stevens Johnson Syndrome. Your doctor will stop
your treatment in this case.
• If you notice bruising, fever, you are looking pale or
you have a severe sore throat. These may be the
first signs of an abnormality of the blood, including
decreases in the number of red cells, white cells
or platelets and bone marrow suppression, please
consult your doctor. Your doctor may take regular
blood samples to test for these effects.
• Skin rash and fever with swollen glands, as these
may be signs of a hypersensitivity reaction or
a particular allergic reaction known as DRESS
syndrome. If these are severe and you also
experience pain and inflammation of the joints this
could be related to a condition called Systemic
Lupus Erythematosus.
• If you experience an increase in the number of
your generalized fits (tonic-clonic seizures).
Other side-effects that may occur are:
• Common side effects (may affect up to
1 in 10 people): decreased appetite, headaches,
unsteadiness, difficulty in controlling movements,

dizziness, drowsiness, stomach ache and cramps,
feeling sick, being sick (vomiting), skin rash including
measles-like reactions which are mild, hives.
Uncommon side effects (may affect up to 1 in
100 people): aggressive behaviour, nightmares,
depression, thinking about suicide, psychotic disorder,
disturbance to sleep patterns, shaking, abnormal or
uncoordinated movements, sluggishness, inability to
concentrate, short sightedness, hiccups, diarrhoea,
enlarged gums, swollen tongue, blood in the urine,
vaginal bleeding, fatigue, irritability, weight loss,
feelings of persecution, hyperactivity.
Not known (frequency cannot be estimated
from the available data): sense of great well being,
an increased sex drive, extreme restlessness, loss of
interest in activities, violent muscle contractions, hair
loss, swelling of the lymph glands

Reporting of side effects

If you get any side effects, talk to your doctor or
pharmacist. This includes any possible side effects
not listed in this leaflet. You can also report side
effects directly (see details below). By reporting side
effects you can help provide more information on the
safety of this medicine.

United Kingdom

Yellow Card Scheme


HPRA Pharmacovigilance
Earlsfort Terrace
IRL - Dublin 2
Tel: +353 1 6764971
Fax: +353 1 6762517


5. How to store Zarontin
Keep out of the sight and reach of children.
Do not store above 25 °C.
Do not use Zarontin after the expiry date which is
stamped on the carton after EXP. The expiry date
refers to the last day of that month.
Do not throw away medicines via wastewater or
household waste. Ask your pharmacist how to throw
away medicines you no longer use. These measures
will help protect the environment.

6. Contents of the pack and other
What Zarontin contains

- The active ingredient is ethosuximide.
Each 5 ml dose contains 250 mg of ethosuximide.
- The other ingredients are sodium citrate, sodium
benzoate (E211), citric acid monohydrate, glycerol,
sucrose, raspberry flavour NN 05557 (including
glucose) saccharin sodium and water (see section
2 Zarontin contains sucrose and glucose).
Zarontin contains sucrose 3 g and glucose
4.6 mg in each 5 ml.

What Zarontin looks like and
contents of the pack

Zarontin 250 mg/5 ml Syrup is a clear yellowish to
pinkish dye free raspberry flavoured syrup. Zarontin
Syrup is available in bottles containing 200 ml,
250 ml or 300 ml of syrup.
Not all pack sizes may be marketed.

Marketing Authorisation Holder

Pfizer Limited
Ramsgate Road
CT13 9NJ

Pfizer Healthcare Ireland
9 Riverwalk
National Digital Park
Citywest Business Campus
Dublin 24

Famar Orleans
5 Avenue de Concyr
45071 Orleans
Cedex 02

Company Contact Address

For further information on your medicine, please
contact Medical Information at:
UK – Pfizer Limited, Walton Oaks, Tadworth, Surrey,
KT20 7NS, Tel 01304 616161
Ireland – Pfizer Healthcare Ireland, 9 Riverwalk,
National Digital Park, Citywest Business Campus,
Dublin 24, Tel 1800 633 363
This leaflet was last revised in the United Kingdom:
This leaflet was last revised in Ireland: 06/2014
Ref Code: ZA 16_0 UK/IRE



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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.