Consumer Medicine Information
What is in this leaflet
This leaflet answers some common questions about Gantin.
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
Gantin against the benefits it is expected to 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 Gantin is used for
What Gantin does
Gantin is used to control epilepsy. Epilepsy is a condition where you have repeated
seizures (fits). There are many different types of seizures, ranging from mild to
Gantin is also used to treat neuropathic pain, a type of pain caused by damage to
This medicine belongs to a group of medicines called anticonvulsants.
How Gantin works
This medicine is thought to work by controlling brain chemicals which send signals
to nerves to help control seizures or neuropathic pain.
Gantin also has pain relieving effects.
Your doctor may have prescribed Gantin in addition to other medicines that you may
be taking. This may be necessary if your current treatment is no longer working as
Your doctor may have prescribed Gantin for another reason.
Gantin may lead to dependence on this medicine.
Ask your doctor if you have any questions about why this medicine has been prescribed
This medicine is available only with a doctor's prescription.
Use in children
There is not enough information to recommend the use of this medicine in children:
under the age of 3 years to control epilepsy, or
under the age of 18 years to treat neuropathic pain.
Before you take Gantin
When you must not take it
Do not take Gantin if you have an allergy to:
any medicine containing gabapentin, the active ingredient in Gantin
any of the ingredients listed at the end of this leaflet.
Some of the symptoms of an allergic reaction may include:
shortness of breath
wheezing or difficulty breathing
swelling of the face, lips, tongue or other parts of the body
rash, itching or hives on the skin.
Do not take Gantin after the expiry date printed on the pack or if the packaging is
torn or shows signs of tampering.
If it has expired or is damaged, return it to your pharmacist for disposal.
If you are not sure whether you should start taking Gantin, talk to your doctor or
Before you start to take it
Tell your doctor or pharmacist if you have allergies to:
any other medicines, especially barbiturates or any other anticonvulsant medicines
any other substances, such as foods, preservatives or dyes.
Tell your doctor if you have or have had any of the following medical conditions:
mixed seizure disorders that include absence seizures.
Tell your doctor if you are pregnant or plan to become pregnant.
Gantin may affect your developing baby if you take it during pregnancy. However, it
is very important to control your fits while you are pregnant. If it is necessary
for you to take Gantin, your doctor can help you decide whether or not to take it
Tell your doctor if you are breast-feeding or plan to breast-feed.
Gantin passes into breast milk. The effect on your breast-fed baby is unknown.
If you do breast-feed, watch your baby carefully.
If your baby develops a skin rash, becomes sleepy or has unusual symptoms, don't breast-feed
again until you speak to your doctor.
Your doctor can discuss the risks and benefits of breast-feeding with you.
If you have not told your doctor or pharmacist about any of the above, tell them before
you start taking Gantin.
Taking other medicines
Tell your doctor or pharmacist if you are taking any other medicines, including:
all prescription medicines
all medicines, vitamins, herbal supplements or natural therapies you buy without a
prescription from a pharmacy, supermarket, naturopath or health food shop.
Some medicines may be affected by Gantin or may affect how well it works. You may
need different amounts of your medicine, or you may need to take different medicines.
Your doctor or pharmacist will advise you accordingly.
Tell your doctor or pharmacist if you are taking any of the following:
cimetidine, a medicine used to treat stomach or duodenal ulcers
antacids, medicines used to treat heartburn or reflux
opioids, medicines used to treat severe pain e.g. morphine.
Your doctor and pharmacist have more information on medicines to be careful with or
avoid while taking Gantin.
How to take Gantin
Follow all directions given to you by your doctor or pharmacist carefully.
They may differ from the information contained in this leaflet.
If you do not understand the instructions on the pack, ask your doctor or pharmacist
How much to take
Your doctor will tell you how many capsules/tablets you need to take each day. This
may depend on your age, your condition and whether or not you are taking any other
Your doctor may recommend that you start with a low dose of Gantin and slowly increase
the dose to the lowest amount needed to control your epilepsy/convulsions or neuropathic
How to take it
Swallow Gantin whole with a full glass of water.
Gantin 800 mg tablets can be divided in half along the breakline, if advised by your
doctor or pharmacist.
When to take it
Take Gantin at about the same time each day.
Taking Gantin at the same time each day will have the best effect. It will also help
you remember when to take the capsules/tablets.
If you are taking Gantin three times a day, do not allow more than 12 hours between
It does not matter if you take Gantin before or after food.
How long to take it
Continue taking your medicine for as long as your doctor tells you.
Gantin helps control your condition, but does not cure it. Therefore you must take
your medicine every day, even if you feel well.
Do not stop taking Gantin, or lower the dosage, without checking with your doctor.
Do not let yourself run out of medicine over the weekend or on holidays.
Stopping Gantin suddenly may cause unwanted side effects or make your condition worse.
Your doctor will slowly reduce your dose before you can stop taking it completely.
If you forget to take it
If it is almost time for your next dose (within 4 hours), skip the dose you missed
and take your next dose when you are meant to.
Otherwise, take it as soon as you remember, and then go back to taking Gantin as you
Do not take a double dose to make up for the dose that you missed.
This may increase the chance of you getting an unwanted side effect.
If you are not sure what to do, ask your doctor or pharmacist.
If you have trouble remembering to take Gantin, ask your pharmacist for help.
If you take too much (overdose)
Immediately telephone your doctor or Poisons Information Centre (telephone 13 11 26)
for advice, or go to Accident and Emergency at the nearest hospital, if you think
that you or anyone else may have taken too much Gantin.
Do this even if there are no signs of discomfort or poisoning.
You may need urgent medical attention.
Symptoms of an overdose may include you falling unconscious, feeling drowsy, weak,
unsteady when walking, having double vision, slurred speech or diarrhoea.
While you are taking Gantin
Things you must do
If you are about to be started on any new medicine, remind your doctor and pharmacist
that you are taking Gantin.
Tell any other doctors, dentists, and pharmacists who treat you that you are taking
If you are going to have surgery or emergency treatment, tell the surgeon or anaesthetist
that you are taking Gantin.
Tell your doctor immediately if you have any thoughts of suicide or self-harm, any
unusual changes in mood or behaviour, or show signs of depression.
Some people being treated with anti-epileptics such as Gantin have had thoughts of
harming or killing themselves.
Patients and caregivers should be alert and monitor for signs and symptoms of suicide,
thoughts or talk of death or suicide
thoughts or talk of self-harm or harm to others
any recent attempts of self-harm
new or an increase in aggressive behaviour, irritability or agitation
new onset of or worsening of depression.
Mention of suicide or violence must be taken seriously.
If you or someone you know is demonstrating these warning signs of suicide while taking
Gantin, contact your doctor or a mental health professional right away.
Tell your doctor if you feel Gantin is not helping your condition.
Your doctor may need to change your medicine.
Tell your doctor if, for any reason, you have not taken Gantin exactly as prescribed.
Otherwise, your doctor may change your treatment unnecessarily.
If you become pregnant while taking this medicine, tell your doctor immediately.
If you need to have any medical tests while you are taking Gantin, tell your doctor.
It may interfere with the results of some tests.
If you are going to have any surgery or procedure, including dental surgery, tell
your surgeon, doctor or dentist that you are taking this medicine.
Keep all of your doctor's appointments so that your progress can be checked.
Your doctor will check your progress and may want to take some tests from time to
time. This helps to prevent unwanted side effects.
Things you must not do
Do not take Gantin to treat any other complaints unless your doctor tells you to.
Do not give Gantin to anyone else, even if their symptoms seem similar to yours or
they have the same condition as you.
Do not stop taking Gantin or lower the dosage without checking with your doctor.
Stopping Gantin suddenly, if you have epilepsy, may cause unwanted side effects or
make your condition worse. Your doctor will slowly reduce your dose before you can
stop taking it completely.
Things to be careful of
Be careful driving or operating machinery until you know how Gantin affects you.
As with other anticonvulsant medicines, Gantin may cause drowsiness, dizziness, light-headedness
or sleepiness in some people. Make sure you know how you react to Gantin before you
drive a car, operate machinery, or do anything else that could be dangerous if you
are dizzy or light-headed. If this occurs do not drive.
Children should not ride a bike, climb trees or do anything else that could be dangerous
if they are feeling drowsy or sleepy.
Be careful when drinking alcohol while you are taking Gantin.
Combining Gantin and alcohol can make you more sleepy, dizzy or light-headed. Your
doctor may suggest you avoid alcohol while you are being treated with Gantin.
Tell your doctor or pharmacist as soon as possible if you do not feel well while you
are taking Gantin.
All medicines can have side effects. Sometimes they are serious, most of the time
they are not. You may need medical attention if you get some of the side effects.
It can be difficult to tell whether side effects are the result of taking Gantin,
effects of your condition or side effects of other medicines you may be taking, for
this reason it is important to tell your doctor of any change in your condition.
If you are over 65 years of age you may have an increased chance of getting side effects.
Ask your doctor or pharmacist to answer any questions you may have.
If you get any side effects, do not stop taking Gantin without first talking to your
doctor or pharmacist.
Tell your doctor if...
Tell your doctor or pharmacist if you notice any of the following and they worry you:
dizziness* or light-headedness
feeling tired or drowsy*
forgetfulness, loss of concentration or confusion
changes in your weight*
nausea and/or vomiting,* indigestion
dry mouth, red swollen gums
muscle pain or cramps, back pain
swelling of the hands or feet
runny or blocked nose
bronchitis*, lung infection*
sore throat and discomfort when swallowing, coughing.
The above list includes the more common side effects of your medicine. They are usually
mild and short-lived.
Tell your doctor as soon as possible if...
Tell your doctor as soon as possible if you notice any of the following:
weakness, unsteadiness when walking including falling, reduced co-ordination or slowed
unusual changes in mood* or behaviour such as restlessness, nervousness, or excitement
signs of new onset of, or increased irritability or agitation
signs of depression
seeing or hearing things that are not these, irrational thinking
blurred or double vision, uncontrollable jerky eye movements, difficulty seeing
signs of frequent infections such as fever, severe chills, sore throat or mouth ulcers.
trouble breathing or shallow breaths (respiratory depression)
loss of consciousness
The side effects in the above lists marked * have been specifically reported in children
Go to hospital if...
Tell your doctor immediately or go to Accident and Emergency at your nearest hospital
if you notice any of the following:
more frequent or more severe seizures (fits)
chest pain, a very fast heart rate
sudden signs of allergy such as rash, itching or hives, fever, swollen lymph glands,
swelling of the face, lips, tongue or other parts of the body, shortness of breath,
wheezing or difficulty breathing.
The above list includes very serious side effects. You may need urgent medical attention
or hospitalisation. These side effects are very rare.
Tell your doctor or pharmacist if you notice anything else that is making you feel
Other side effects not listed above may also occur in some people.
Some of these side effects (for example, changes in thyroid function, structure of
bones, high cholesterol, levels of sugar in your blood or blood pressure) can only
be found when your doctor does blood tests from time to time to check your progress.
Do not be alarmed by the list of possible side effects.
You may not experience any of them.
After taking Gantin
Keep your capsules/tablets in the pack until it is time to take them.
If you take the capsules/tablets out of the pack they may not keep well.
Keep your capsules in a cool dry place where the temperature stays below 30°C.
Keep your tablets in a cool dry place where the temperature stays below 25°C.
Do not store Gantin or any other medicine in the bathroom or near a sink. Do not leave
it on a window sill or in the car.
Heat and dampness can destroy some medicines.
Keep it 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 or pharmacist tells you to stop taking Gantin or the expiry date has
passed, ask your pharmacist what to do with any medicine that is left over.
What it looks like
300 mg - Yellow capsule
400 mg - Orange capsule
Each pack contains 100 capsules.
800 mg - White, elliptical, film-coated tablet, with bisecting score on both sides
and debossed with "NT" and "26" on one side.
Each pack contains 100 tablets.
Gantin 300 mg - 300 mg gabapentin
Gantin 400 mg - 400 mg gabapentin.
iron oxide yellow (300 mg/ 400 mg)
iron oxide red (400 mg).
Gantin 800 mg - 800 mg gabapentin.
Opadry white YS-1-18111.
Gantin does not contain sucrose, gluten, tartrazine or any other azo dyes.
Gantin is supplied in Australia by:
Pfizer Australia Pty Ltd
ABN 50 008 422 348
38-42 Wharf Road
West Ryde NSW 2114
Toll Free Number 1800 675 229
Australian Registration Numbers
300 mg capsules: AUST R 78624
400 mg capsules: AUST R 78625
800 mg tablets: AUST R 78626
Date of preparation
This leaflet was prepared in November 2017.
© Pfizer Australia Pty Ltd 2014.
® Registered trademark.