USE OF VIGABATRIN IN PREGNANCY

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(Date of issue: July 2019, Version: 2)

This is a UKTIS monograph for use by health care professionals. For case-specific advice please contact UKTIS on 0344 892 0909. To report an exposure please download and complete a pregnancy reporting form. Please encourage all women to complete an online reporting form.

A corresponding patient information leaflet on vigabatrin use in pregnancy is available at www.medicinesinpregnancy.org.

Summary

Vigabatrin is an anticonvulsant used predominantly in combination with other antiepileptic drugs (AEDs) in the treatment of resistant partial seizures, with or without secondary generalisation, where all other potential drug combinations have proved ineffective, are contraindicated, or not tolerated.

There is very limited information on the use of vigabatrin in pregnancy. Fetal toxicity and congenital malformation has been reported in animal studies. An initial report by the manufacturer of high rates of congenital malformation among children exposed in utero is likely to be heavily biased by concomitant maternal medication use and retrospective reporting.

The very limited available data, derived from isolated case reports, small uncontrolled case series, cohort studies and a network meta-analysis do not currently provide reputable evidence which demonstrates that vigabatrin use in pregnancy increases the risk of congenital malformation, miscarriage, intrauterine fetal death, preterm delivery or intrauterine growth restriction. However, given the available data is highly limited, it is not possible to exclude the risk of such effects and further studies are therefore required.

Vigabatrin therapy in the non-pregnant patient has been associated with retinal and optic atrophy, peripheral field loss and electroretinogram abnormalities. It is unknown whether in utero exposure is also associated with visual disturbance in the offspring and until further data are available the possibility of an effect on fetal visual development cannot be ruled out. 

Vigabatrin may impact upon maternal folate status. UK guidelines state that women who take any anti-epileptic medication should be prescribed high dose folic acid (5mg).

Use of any centrally acting drug throughout pregnancy or near delivery may be associated with withdrawal symptoms in the neonate and/or poor neonatal adaptation syndrome (PNAS). These symptoms are likely to be more severe in infants exposed in utero to more than one CNS acting drug. Delivery should be planned in a unit with neonatal intensive care facilities.

More research is required to define the pregnancy safety profile of vigabatrin. Pregnant women and women of childbearing potential should be made aware of the lack of data for all pregnancy outcomes. Vigabatrin should only be used during pregnancy where benefits of treatment are considered to outweigh any potential risks. In view of the limited human pregnancy data, close monitoring of mother and fetus should be considered with use of vigabatrin in pregnancy. Other risk factors may also be present in individual cases which may independently increase the risk of adverse pregnancy outcome. Clinicians are reminded of the importance of consideration of such factors when performing case-specific risk assessments.

This document is regularly reviewed and updated. Only use full UKTIS monographs downloaded directly from TOXBASE.org to be sure you are using the most up-to-date version. The summaries of these monographs are openly available on UKTIS.org

This is a summary of the full UKTIS monograph for health care professionals and should not be used in isolation. The full UKTIS monograph and access to any hyperlinked related documents is available to health care professionals at www.toxbase.org.

If you have a patient with exposure to a drug or chemical and require assistance in making a patient-specific risk assessment, please telephone UKTIS on 0344 892 0909 to discuss the case with a teratology specialist.

If you would like to report a pregnancy to UKTIS please click here to download our pregnancy reporting form. Please encourage all women to complete an online reporting form.

Disclaimer: Every effort has been made to ensure that this monograph was accurate and up-to-date at the time of writing, however it cannot cover every eventuality and the information providers cannot be held responsible for any adverse outcomes of the measures recommended. The final decision regarding which treatment is used for an individual patient remains the clinical responsibility of the prescriber. This material may be freely reproduced for education and not for profit purposes within the UK National Health Service, however no linking to this website or reproduction by or for commercial organisations is permitted without the express written permission of this service. This document is regularly reviewed and updated. Only use UKTIS monographs downloaded directly from TOXBASE.org or UKTIS.org to ensure you are using the most up-to-date version.