TREATMENTS FOR EPILEPSY
Drugs known as anticonvulsants
What is vigabatrin used for ?
Vigabatrin is most often
used in the treatment of epilepsy, to help control fits
or blackouts. It is usually used with other antiepileptic
drugs. There are many other anticonvulsant drugs. It may
be necessary to try several drugs in different doses or
combinations to find the best therapy for you i.e. least
side effects and maximum effect.
How does vigabatrin work ?
Epileptic seizures (fits or blackouts) happen when an abnormal electrical discharge, like a short circuit causing a spark, occurs in the brain. There are many naturally occurring chemical messengers (or "neurotransmitter") in the brain. One is called GABA and is "inhibitory" on the brain and another one is called glutamate, which "excites" the brain.
Once GABA has worked,
there are other chemicals (or enzymes) in the brain which
are there to break GABA down so that it can no longer
work. In people with normal levels of GABA this prevents
there being too much. In some people it is thought that
there may not be enough GABA in the brain and that this
helps to "trigger" fits. Vigabatrin helps to
stop the breakdown of GABA and so leaves enough of this
chemical to calm the brain and to help prevent the fits
How should I take it ?
The tablets should be
swallowed with at least half a glass of water whilst
sitting or standing, so that they reach the stomach and
do not stick in the throat. Vigabatrin sachets should be
opened and the contents sprinkled into a glass of water,
stirred with a spoon and swallowed as soon as the fizzing
When should I take it ?
Take it as directed on the
medicine label. It is particularly important to take the
drugs regularly each day as directed by your doctor to
make sure that you are getting the best control of your
illness from your medicine.
How long will vigabatrin take to work ?
Vigabatrin should start to
work soon after you start taking it. It may, however,
take some time for your doctor to get the right dose for
you. The aim is for the amount of medicine in your blood
to be high enough to prevent or reduce fits, but low
enough to give you the least amount of side-effects. Do
not attempt to make any changes yourself.
How long will I need to keep taking vigabatrin for ?
Vigabatrin is a "preventative
medicine" and so will usually need to be taken for a
long time. It is important that you keep taking this
medication until your doctor tells you to stop. Do not
stop taking it just because you feel better. If you stop
them before you are advised to do so your condition may
well get worse.
Is vigabatrin addictive ?
Vigabatrin is not thought
to be habit forming. For further discussion, click
Can I stop taking vigabatrin suddenly ?
You should never stop
taking this medication suddenly or without advice from
your doctor as this might mean an increase in fits or
blackouts. Vigabatrin will nearly always need to be
withdrawn slowly. If your doctor decides that you no
longer require this drug it will be withdrawn gradually (like
any treatment for epilepsy) to make sure that your fits
do not return. This will usually be by a slight reduction
in your dose every few weeks. You should therefore not
experience any problems.
What should I do if I forget to take a dose ?
Start again as soon as you
remember unless it is almost time for your next dose,
then go on as before. Do not try to catch up by taking
two or more doses at once as you may get more side-effects.
You should tell your doctor about this next time you meet.
If you are ill and vomit your tablets you should take
that dose again. Missing a dose can cause your fits to
return. The amount in your bloodstream may drop below the
level needed to control your fits.
If you have problems
remembering your doses (as very many people do) ask you
pharmacist, doctor or nurse about this. There are some
special packs, boxes and devices which can be used to
help you remember.
What sort of side-effects might occur ?
Table adapted from UK Psychiatric Pharmacy Group leaflets, with kind permission (www.ukppg.org.uk )
Do not be worried by this list of side effects. You may get none at all. There are other rare side-effects. If you develop any unusual symptoms ask your doctor about them next time you meet.
Will vigabatrin make me drowsy ?
You may feel a little
sleepy and so you must take care if you are allowed to
drive or when operating any type of machinery. This
effect should wear off or at least reduce after you have
been taking them for a while.
Will vigabatrin cause me to put on weight ?
Many people put on some
weight when they start vigabatrin but this is only a real
problem in about one in twenty people. If, however, you
do start to have problems with your weight tell your
doctor next time you meet as he or she can arrange for
you to see a dietician for advice.
Will it affect my sex life?
Drugs can affect desire (libido), arousal (erection) and orgasmic ability. Vigabatrin is not thought to have a significant affect on any of these.
Can I drink alcohol while I am taking vigabatrin ?
You should avoid alcohol
while taking vigabatrin as it may make you feel more
sleepy. This is particularly important if you are allowed
to drive or operate machinery and you must seek advice on
Are there any foods or drinks that I should avoid ?
You should have no
problems with any food or drink other than alcohol (see
Will vigabatrin affect my other medication ?
Tell your doctor of any medicines that you may be taking and also before starting or stopping any other drugs. There are very few problems although vigabatrin may reduce the effectiveness of phenytoin ("Epanutin"). This does not necessarily mean the drugs can not be used together, just that you may need to follow your doctors instructions very carefully.
You should also consult
your pharmacist before buying any medicines over the
If I am taking a contraceptive pill, will this be affected ?
There should be no
problems with vigabatrin.
What if I want to start a family or discover I'm pregnant?
It is important to
consider that there will be a risk to you and your child
from taking a medicine during pregnancy but also a
possible risk from stopping the medicine e.g. getting ill
again. Unfortunately, no decision is risk-free. It will
be for you to decide which is the least risk. All we can
do here is to help you understand some of the issues, so
you can make an informed decision. For your information,
major malformations occur "spontaneously" in
about 2-4% of all pregnancies, even if no drugs are taken.
The main problem with medicines is termed "teratogenicity"
i.e. a medicine causing a malformation in the unborn
child. A medicine causing teratogenicity is called a
"teratogen". Since a baby has completed it's
main development between days 17 and 60 of the pregnancy
(the so-called "first trimester") these first 2-16
weeks are the main concern. After that, there may be
other problems e.g. some medicines may cause slower
growth. The infant may also be affected after birth e.g.
withdrawal effects are possible with some drugs.
B = Animal and human studies indicate a lack of risk but are not fully conclusive
C = Animal studies indicate a risk but there is no safety data in humans
D = a definite risk exists but the benefit may outweigh the risk in some people
X = the risk outweighs any possible benefit
Vigabatrin is not classified, as it is not available in the USA. There is some evidence of cleft palate and so should not usually be taken in pregnancy. You should seek personal advice from your GP, who may then if necessary seek further specialist advice. If you are taking this medicine for epilepsy, then you will need to also consider the risk of seizures as well.
Will I need blood tests ?
You should not need any
routine blood tests with vigabatrin.
Can I drive whilst taking vigabatrin ?
People suffering from epilepsy may drive a motor vehicle (but not a heavy goods vehicle) provided they have been free from fits for one year or if they have only had fits in their sleep for three years. You should consult your doctor about driving.
It is essential that you report epilepsy as well as sudden disabling attacks of loss or partial loss of consciousness to the 'Driver and Vehicle Licensing Centre' (DVLC). The DVLC will then make a medical assessment of your condition consulting with your doctor(s) where necessary. For more information see leaflet 'D100' ('What you need to know about driving licensing') which is available from most post offices, or contact the Driver Enquiry Unit, DVLC, SWANSEA SA6 7JL. (Telephone: 01792 772151 between 8.15 am. to 4.30 pm. on Monday to Friday). You will need to quote your Driver Number whether you write or telephone. Your doctor will be able to advise you, and may wish to access the UK Driver and Vehicle Licensing Agency (DVLA) guidelines website, which has the current DVLA guidelines on anxiety/depression, psychotic disorders, mania and other conditions or for epilepsy. If your doctor advises you not to drive, and you continue to do so, the doctor can inform the DVLA directly, as he or she would be lawfully responsible were you to have an accident. Once told, the DVLA may wish to carry out an enquiry, but you are entitled to drive until there a decision is made.
If you are allowed to drive remember that gabapentin can make you drowsy when you first start taking it and cause you to have difficulty concentrating. You must take great care when driving or operating any type of machinery.
If you are allowed to drive remember that vigabatrin can make you drowsy when you first start taking it and cause you to have difficulty concentrating. You must take great care when driving or operating any type of machinery.
your comments or feedback.
No site can be entirely bias-free. No matter how hard someone tries, training and background will always influence your outlook. We have, however, tried to eliminate bias, and we hope you take these pages in the spirit in which they are provided i.e. a genuine attempt to inform, educate and support.
Information here is based on published data. References include the UK British National Formulary (BNF, published by the British Medical Association and Royal Pharmaceutical Society of Great Britain), Martindale (the extra pharmacopoea, published by RPSGB Pharmaceutical Press), Psychotropic Drug Directory (latest edition), Data Sheet Compendium (UK Manufacturers Data Sheets, published by the Association of British Pharmaceutical Industry), MicroMedex (an independent and extensive CD-ROM based drug information source), UK Psychiatric Pharmacy Group leaflets, Royal College of Psychiatrists advice and guidelines and the current medical literature. Thanks also to all those people who left e-mail comments, suggestions and requests, who have helped shape the site.