Vigabatrin

What is it?

Vigabatrin (Sabril^®) is used to treat epilepsy, usually in combination with other epilepsy medicines.

Is it safe to take vigabatrin in pregnancy?

When deciding whether to use vigabatrin during pregnancy it is important to weigh up the potential benefits to your health and wellbeing against any possible risks to you or your baby, some of which may depend on how many weeks pregnant you are. Use of vigabatrin in pregnancy may sometimes be considered necessary to control epilepsy. Your doctor or specialist will help you make decisions about your treatment.

It is recommended that all women taking anti-epileptic medicines also take high dose folic acid (5mg/day) whilst trying to conceive and during the first trimester of pregnancy. High dose folic acid has to be prescribed by a doctor. For more information please see the folic acid bump leaflet.

What if I have already taken vigabatrin during pregnancy?

If you have taken or are taking any medicines it is always a good idea to let your doctor know that you are pregnant so that you can decide together whether you still need the medicines that you are on and, if so, to make sure that you are taking the lowest dose that works and only for as long as you need to.

If you have epilepsy it is very important that you do not suddenly stop taking vigabatrin as this could be dangerous. Do not make any changes to your medication without first talking to your doctor.

Because of the normal bodily changes associated with a progressing pregnancy, the dose of vigabatrin may need to be adjusted to ensure that symptoms remain well-controlled. Your doctor may offer ongoing monitoring to determine whether dose changes are required.

Can taking vigabatrin in pregnancy cause birth defects in the baby?

A baby’s body and most internal organs are formed during the first 12 weeks of pregnancy. It is mainly during this time that some medicines are known to cause birth defects.

It is currently unclear whether vigabatrin use in pregnancy can cause birth defects in the baby as hardly any pregnant women taking vigabatrin have been assessed using reliable methods.

Vigabatrin use in adults can cause long-term problems with vision. There is therefore a theoretical risk that exposure to vigabatrin in the womb could affect the baby’s eyesight. There is one isolated report of visual problems in a baby whose mother took vigabatrin in pregnancy. However, since then, reports describe six babies who were specifically tested for eyesight problems and were found to be normal.

Can taking vigabatrin in pregnancy cause miscarriage, stillbirth, preterm birth or my baby to be small at birth (low birth weight)?

No studies have investigated whether use of vigabatrin in pregnancy may increase the risk of miscarriage or stillbirth. One very small study found no links with preterm birth, or low birth weight in the baby. Ongoing studies of all of these pregnancy outcomes in women taking vigabatrin are required.

Can taking vigabatrin in pregnancy cause other health problems in the child?

Withdrawal symptoms at birth (neonatal withdrawal)
Withdrawal symptoms are thought to occur when a newborn baby’s body has to adapt to no longer getting certain types of medicines through the placenta.

Vigabatrin works in a similar way to other medicines that are known to cause neonatal withdrawal. There is an isolated report of neonatal withdrawal in a baby who was exposed to vigabatrin in combination with another epilepsy medicine (carbamazepine) in the womb. Close monitoring of your baby for a few days after birth may therefore be advised if you have taken vigabatrin regularly in the weeks before delivery. Monitoring of your baby may be particularly important if you have taken vigabatrin in combination with other anti-epileptic medicines or medicines that act on the brain.

Learning and behavioural problems
A baby’s brain continues to develop right up until the end of pregnancy. It is therefore possible that taking certain medicines (particularly those that act upon the brain) at any stage of pregnancy could have a lasting effect on a child’s learning or behaviour.

No studies have assessed the learning and behaviour of children exposed in the womb to vigabatrin.

Will my baby need extra monitoring?

As part of their routine antenatal care most women will be offered a scan at around 20 weeks of pregnancy to look for birth defects and to check the baby’s growth. Women with epilepsy are likely to be more closely monitored during pregnancy to ensure that they remain well throughout and that their baby is growing and developing as expected. 

Because the effects of vigabatrin on a developing pregnancy are unknown, your doctor may wish to monitor you more closely and may offer you the option of having more detailed anomaly scans.

If you have taken vigabatrin around the time of delivery your baby may require extra monitoring after birth because of the possible risk of neonatal withdrawal.

Are there any risks to my baby if the father has taken vigabatrin?

We would not expect any increased risk to your baby if the father took vigabatrin before or around the time you became pregnant.

Who can I talk to if I have questions?

If you have any questions regarding the information in this leaflet please discuss them with your health care provider. They can access more detailed medical and scientific information from www.uktis.org.