Best practice guidelines for the management of women with epilepsy. The Women with Epilepsy Guidelines Development Group

Teratogenic potential of the newer antiepileptic drugs: what is known and how should this influence prescribing?

The treatment of women of childbearing age who have epilepsy raises many questions because of the interactions between epilepsy, antiepileptic therapy and different aspects of reproductive life. Menstrual cycle disorders and reduced fertility have been partially ascribed to antiepileptic drugs (AEDs). Furthermore, most AEDs induce the cytochrome P450 (CYP) enzymatic system, altering the metabolism of sex hormones and contributing to the failure of oral contraceptives. Pregnancy represents, in this context, the most critical period because of the well known teratogenic potential of all established AEDs. For most of these drugs no specific patterns of malformations have been identified, although during the past few decades basic knowledge has been acquired, particularly concerning the mechanisms of AED-induced teratogenesis and related risk factors. These issues form the basis of the current guidelines for the management of epilepsy in pregnant women. In the past decade, several new AEDs have been introduced into clinical practice. For a number of reasons, these drugs appear to be more favourable than the older ones as treatments for epilepsy in women of childbearing age. They possess a good pharmacokinetic profile that makes them more stable during pregnancy, and they have a low potential for interaction with other drugs. They are also less likely than the older AEDs to be metabolised to compounds that are teratogenic. Furthermore, most of them do not possess antifolate properties. With the exception of topiramate and vigabatrin, the newer AEDs do not appear to be teratogenic in animals when administered in subtoxic doses. However, animal teratology may not be a reliable predictor of human teratogenicity, and there is a significant lack of information regarding the teratogenic profile of these newer agents in humans. Because clinical experience with these agents is limited, it is advisable to avoid exposure of the embryo to these drugs when pregnancy is planned. The establishment of pregnancy registries could allow for the rapid collection of data related to the administration of new AEDs in pregnancy and the outcomes of such exposure.

Anti-epileptic drugs in pregnancy: current safety and other issues

Women with epilepsy of child-bearing years have their own considerations, which must be taken into account if management of their epilepsy is to be optimised. The main issues to consider include the effects of: female hormones on seizure control, anti-epileptic drugs (AEDs) on hormonal methods of contraception, epilepsy and AEDs on fertility, epilepsy and AEDs on pregnancy itself, pregnancy on AEDs and seizure control and epilepsy, seizures and AEDs on the developing embryo/fetus. Whereas previous studies have concentrated on the increased risk of major congenital malformations from prenatal AED exposure, the effects on cognitive and behavioural development are increasingly being explored. This article looks at the evidence currently available for all of the above issues, taking into account the increased number of AEDs which are now available.

Major malformations in offspring of women with epilepsy

BACKGROUND

The offspring of women with epilepsy are at an increased risk of major congenital malformations, but the impact of the various contributing factors remains unresolved.

METHOD

In 1980 through 1998, the authors prospectively followed up 970 pregnancies in women with epilepsy at a single maternity clinic. Of their 979 offspring, 740 were exposed to maternal antiepileptic drugs (AED) during the first trimester of pregnancy and 239 were not exposed. Maternal AED levels and serum folate concentrations were measured at the end of the first trimester. Logistic regression analysis was applied to identify factors associated with the occurrence of major malformations in the fetuses and newborns.

RESULTS

Major malformations were detected in 28 fetuses (3.8%) exposed to maternal AED and in 2 (0.8%) not exposed (p = 0.02). After logistic regression analysis, the occurrence of major malformations was independently associated with use of carbamazepine (adjusted OR 2.5; 95% CI 1.0 to 6.0), use of valproate (4.1; 1.6 to 11), use of oxcarbazepine (10.8; 1.1 to 106), low serum folate concentration (5.8; 1.3 to 27), and low maternal level of education (3.0; 1.3 to 6.8). Major malformations were not associated with seizures during the first trimester (0.6; 0.1 to 2.9).

CONCLUSIONS

Major malformations in the offspring of mothers with epilepsy are associated with use of AED during early pregnancy, and also with low serum folate concentrations and a low level of education.

Epilepsy and pregnancy: Report of an Epilepsy Research Foundation Workshop

Pregnancy in women with epilepsy (WWE) is known to be associated with a higher risk of congenital malformations than is associated with pregnancy in non-epileptic women. Several factors have been identified to account for the increased risk, including the direct teratogenic effects of antiepileptic drug (AED) therapy, indirect effects of these drugs by interfering with folate metabolism, genetic abnormalities in drug or folate metabolism, and possibly an arrhythmogenic effect of maternal drug therapy on the embryonic heart, leading to ischaemia in developing tissues. A harmful effect of maternal seizures on the developing embryo has not been proven, although seizures and status epilepticus account for most of the excess maternal mortality in women with epilepsy. Abrupt withdrawal of drug therapy by the mother may be an important contributory factor. Less is known about the psychomotor development of children born to mothers with epilepsy because few studies have been designed to follow their progress throughout childhood. Retrospective studies suggest that impaired cognitive development may be associated with maternal drug therapy, particularly valproate. There is an urgent need to evaluate these risks and, with this in mind, several prospective registers have been set up to collect data from pregnancies in women with epilepsy.

Patient's perspective on epilepsy: self-knowledge among Omanis

Improving patients' knowledge has been suggested to improve their symptoms and prognosis. Very little is known about epileptic patient's knowledge of their illness in cross-cultural settings. This pilot study investigated what Omani patients know about their disorder. Patients attending a tertiary hospital completed a structured knowledge questionnaire to elicit information pertaining to aetiology, safety, compliance with medication regimes, legal and employment issues concerning epilepsy.Although correctly endorsing issues related to their medication, this cross-cultural sample was found to have limited knowledge about their condition. In particular, most patients were unable to give accurate indications of epilepsy, neither were they able to give correct responses to questions pertaining to safety and compliance. There is a need for improving patient's knowledge. As with other chronic disorders, people with epilepsy in Oman should receive systematic health education about how to manage the condition most effectively.

Information recalled by women taking anti-epileptic drugs for epilepsy: a questionnaire study

Women with epilepsy have different needs from men, particularly associated with childbearing. Despite clinical guidelines, the care of women with epilepsy remains suboptimal. The aim of this study was to establish whether women with epilepsy recall being given information on topics relating to childbearing. Design of study and methods included a postal questionnaire study of 795 women with epilepsy and of childbearing age. The respondents were identified through both general practices and hospital clinics as part of the Clinical Standards Advisory Group study into Epilepsy Services. Of those women who considered the questions personally relevant, 38-48% recalled receiving information about contraception, pre-pregnancy planning, folic acid and teratogenicity, with lower overall proportions among adolescent women. The proportions that recalled receiving information about vitamin K, safety in child-care and breast-feeding were lower at 12, 24 and 24%, respectively. While it is recognised that information provided may not be recalled, our results suggest that further measures are required to improve the effectiveness of information provision in the UK in relation to women of childbearing age with epilepsy.

Outcome of pregnancy in women attending an outpatient epilepsy clinic: adverse features associated with higher doses of sodium valproate

The risk of an adverse outcome to pregnancy is increased in women with epilepsy. This is partly attributable to antiepileptic drugs. Guidelines for the management of pregnancy in women with epilepsy generally advise against polytherapy but make no distinction between the risks of different drugs. Several recent studies have however shown greater risk of adverse outcome in offspring exposed to sodium valproate in utero, particularly at higher doses. The outcome of pregnancy was monitored to identify antiepileptic drug treatment associated with a poor outcome in a mainly prospective study of women attending an outpatient clinic. From January 1990 to December 1999 all 69 pregnancies in women referred to the clinic were monitored. Drug treatments and other risk factors were recorded. In each child dysmorphic features, developmental delay and structural anomalies were assessed and graded. Data were analysed for drug- and dosage-dependent differences in outcome. In each assessment area a positive association between adverse outcome and dose was found for sodium valproate but not for carbamazepine. Severe adverse outcomes were found only in children exposed to sodium valproate at maternal doses above 1000 mg per day.

Self-discontinuation of antiepileptic medication in pregnancy: detection by hair analysis

PURPOSE

Concerns over teratogenicity of antiepileptic drugs (AEDs) during pregnancy must be balanced against the risks of seizures to the mother and developing fetus. Pharmacokinetic changes and vomiting may alter drug levels, but more important may be the patient's decision to stop medication before or during pregnancy. Compliance assessment traditionally relies either on self-reporting or on AED plasma level monitoring; neither provides reliable information on drug-taking behaviour over an extended interval (e.g., before, during, and after pregnancy).

METHODS

We have used hair analysis to assess AED-taking behavior in pregnant women compared with nonpregnant female controls. Twenty-six pregnant women [mean age, 27.5 +/- 6.7 (SD) years] and 13 nonpregnant female epilepsy outpatients (mean age, 31.9 +/- 8.3 years) were studied. Carbamazepine (CBZ) or lamotrigine (LTG) concentrations were measured in 1-cm hair segments, and the within-subject variance in segmental hair concentrations of these drugs was calculated for each group. The variances of each group were then compared by using a variance ratio test.

RESULTS

The variance of AED concentration in hair differed significantly between the pregnant and nonpregnant groups [variance ratio, 1.59 (p < 0.01)]. Four (15%) of the 26 pregnant patients had little or no AED in their proximal hair segments compared with more distal segments, apparently having discontinued their medication during pregnancy. Only one of these later disclosed having stopped her medication. One pregnant woman whose hair profile was similar to controls died suddenly at 30 weeks of gestation.

CONCLUSIONS

This study confirms the perception that pregnant women with epilepsy frequently stop or greatly reduce their prescribed medication, usually without reference or acknowledgement to their clinician.

Hazards of assisted conception in women with severe medical disease

The issues relating to assisted reproduction in women with severe medical disease can be divided into the likely effect of pregnancy upon the medical condition, and how the medical condition may adversely affect pregnancy outcome. In addition, consideration of the hazards relating to the process of assisted conception, in particular the risk of ovarian hyperstimulation syndrome and multiple pregnancy, must be remembered. In some women, successful assisted reproduction may result in a life-threatening pregnancy. Clinicians advising women about assisted conception should be aware of the medical conditions that are absolute contra-indications to pregnancy. Some women with severe medical disease may have a significantly reduced life expectancy, in which case ethical issues regarding the future welfare of the child must be considered. Examples include sickle cell disease, cystic fibrosis and HIV. One of the biggest advantages of assisted reproduction for women with severe medical disorders is that the pregnancy is planned. Thus, there is an opportunity for the patient to be informed fully about any risks, both to herself and her fetus. This article reviews the general management of women with severe medical disorders who seek assisted reproduction and gives specific guidelines for the more common conditions.

Clinical guidelines for the management of epilepsy in adults with an intellectual disability

Clinical guidelines exist for the treatment of chronic epilepsy and epilepsy in women (2). This publication provides guidance for the clinician investigating and managing epilepsy in adults who have an intellectual disability as defined by an Intelligence Quotient (IQ) of less than 70, onset in the developmental period and difficulties with adaptive functioning.

Assessment of teratogenic risk

Although the association between prenatal exposure to old generation antiepileptic drugs (AEDs) and major congenital malformations has been studied for many years, it is not clear whether any specific AED, or AED combination, is more harmful than others, or whether any pattern of malformations can be considered specific for any given drug. Relationships between dosage and plasma concentrations of AEDs and the risk of malformations also need to be clarified. The greatest limitation of all studies performed to date is the fact that none included a sufficiently large number of pregnancies. For newer generation AEDs the teratogenic risk, if any, is unknown. Large prospective studies are needed. The best approach is the establishment of registries through international collaboration. Inclusion of non-epileptic controls and untreated women is not strictly necessary to evaluate the comparative teratogenic risk of AEDs. The modalities of data collection should be pre-defined; common protocols, sufficiently exhaustive but at the same time easy to perform, should be shared from the beginning. Information on the presence or absence of major malformations or prenatal growth retardation, and on all major factors that may affect the teratogenic endpoints should be obtained. Study designs should ensure high quality data recording, and adequate quality assurance and auditing procedures. Further requisites are a clear definition of congenital malformation and prolonged follow-up to detect the occurrence of congenital malformations not detected at birth.

Do we need any more new antiepileptic drugs?

The last decade has seen the licensing of nine new antiepileptic drugs (AEDs) with more to come. Despite this, only 58 and 63% of patients with localisation-related and newly diagnosed epilepsy, respectively, had been seizure-free for more than a year in separate prospective outcome studies undertaken at the Epilepsy Unit in Glasgow. Data will be presented to support the hypothesis that adolescent and adult epileptic patients comprise two distinct populations. Around 60% will be controlled on monotherapy with the first or second choice AED, while the majority of the remainder is difficult-to-control. It is for this latter group and the many pharmacoresistant paediatric patients with encephalopathic syndromes that we need new AEDs. For a successful clinical outcome, patients must be able to tolerate the treatment. Neurotoxic, sedative, cognitive and psychiatric symptoms, dysmorphic and other long-term side effects, and teratogenesis plague the current crop of AEDs. Pharmacokinetic and pharmacodynamic interactions complicate the situation still further. These problems may, in part, be a consequence of combining drugs with similar mechanisms of action. Unravelling the genetics of the epilepsies will provide a range of tempting targets for pharmacological intervention. We need, also, models of refractory epilepsy to help identify promising therapies. An efficient regulatory trial programme will ensure rapid availability of new AEDs for the many children and adults whose lives continue to be blighted by seizures.

CPD-Education and self-assessment: Epilepsy and pregnancy

Pregnancies in women with epilepsy are high risk and need careful management by both the medical and obstetric teams due to the increased incidence of complications and adverse outcomes of pregnancy. By the time a pregnant woman with epilepsy presents, the foetus is virtually fully formed and the opportunity for altering drug treatment has passed. Women need to be counselled and told to seek advice about their anticonvulsant therapy should they wish to become pregnant. All major anticonvulsant drugs are teratogenic but the main risk to the developing foetus appears to be when the mother is on polytherapy especially if sodium valproate forms part of the combination. Folate supplements (5 mg) before conception are advisable. There appears to be a minor but significant increased risk of maternal complications in women with epilepsy such as hyperemesis gravidarum, pre-eclampsia and eclampsia, vaginal bleeding and premature labour. In the majority of women seizure control will not alter during pregnancy. Oral vitamin K should be given to the mother receiving enzyme-inducing antiepileptic drugs. Post-natal infant development: there is an increased risk of prematurity (9-11%), stillbirth, neonatal and perinatal death, haemorrhagic disease of the newborn, low Apgar scores and low birth weight (7-10%). Breast feeding: virtually all the anticonvulsant drugs are excreted in breast milk in low concentrations. Feeding difficulties, irritability and lethargy can occur. However, the benefits of breast feeding usually far outweigh any minor risks to the baby.

Continuing professional development: medico-legal aspects of epilepsy

Generally protection against possible litigation and good clinical practice go hand in hand. Situations in which the law has special relevance for people with epilepsy, those who work with them, and their clinicians are reviewed with special reference to the topics of driving, employment, duties of social carers, the clinician's everyday role, the responsibilities of researchers and epilepsy and the criminal law. What constitutes professional negligence is discussed, with special reference to the United Kingdom. Clinicians are advised to think clearly, write clearly, communicate clearly and have a good relationship with their patients.

Epilepsy--doctor's dilemma, lawyer's delight? Medico-legal consequences of practising in the field of epilepsy report of an International League Against Epilepsy British Branch meeting--Edinburgh, April 2000

Six cases are described where the medical management of a person's epilepsy was brought under legal scrutiny. Lessons learnt from this educational exercise include improving doctor patient communication, the function of a Coroner's Court, when is misdiagnosis negligent, the vagaries of expert witnesses, should failure to diagnose a tumour be blamed on the physician or the service when facilities are inadequate, is failure to recognise a rare drug interaction, failure to warn against an interaction, or failure to take a proper history, negligent? The conference also examined the legal ramifications of the nurse/doctor relationship in epilepsy care, the place of epilepsy guidelines and, due to its interactive nature, reflected on the audience's epilepsy knowledge, which, in places seemed significantly deficient. It was a gripping educational exercise.

The star systems: overview and use in determining antiepileptic drug choice

An explosion in antiepileptic drug (AED) therapy began in the 1990s with the licensing of 9 new chemical entities and more to come. Important differences between AEDs may not be detected by regulatory trials, which are designed to satisfy licensing requirements and often diverge considerably from everyday clinical practice. The Star Systems have been developed as evidence-based yet pragmatic and flexible models for comparing AEDs. Each drug has been judged across a range of criteria, including mechanism of action, pharmacokinetics, ease of use, efficacy, tolerability, safety, interaction profile and a 'comfort factor'. A score has been allocated under each category and systems have been devised for patients with newly diagnosed epilepsy and those with difficult-to-control seizures requiring combination therapy. The choice of treatment should involve assessment of patient-related factors, accurate classification of seizure type and syndrome, married with an understanding of the pharmacology of the AEDs. A staged management plan should be formulated when initiating treatment with the aim of preventing the development of refractory epilepsy. When using combinations of AEDs, the mechanism of action of each agent should be taken into consideration. Such an individualised approach to management will optimise the chance of attaining remission and help many more patients achieve a fulfilling life.

Open study evaluating lamotrigine efficacy and safety in add-on treatment and consecutive monotherapy in patients with carbamazepine- or valproate-resistant epilepsy

Lamotrigine is a broad-spectrum antiepileptic drug that blocks sodium channels, thereby inhibiting the pre-synaptic release of excitatory neurotransmitters. The primary aim of the study was to evaluate lamotrigine add-on therapy and consecutive monotherapy in patients with epilepsy whose seizures were not controlled by carbamazepine or valproate. One hundred and twenty six epilepsy patients at 18 centres in Poland were recruited into a lamotrigine substitution study. In all patients, existing seizures were poorly controlled with valproate (n= 63) or carbamazepine (n= 63) monotherapy. The study consisted of four phases: (1) a 4-week lamotrigine dose-escalation phase, (2) an 8-week lamotrigine add-on phase, (3) an 8-week carbamazepine/valproate withdrawal phase, and (4) an 8-week lamotrigine monotherapy phase. Of 126 patients recruited into the study, 107 (85%) completed dose-escalation and add-on therapy with lamotrigine and 85 (68%) completed lamotrigine monotherapy. Fifty percent of patients during add-on therapy and 53% during lamotrigine monotherapy experienced at least 50% reduction in total seizures (responders) compared to the pre-study period. Approximately 20% of patients during add-on therapy and 27% during lamotrigine monotherapy were seizure free. Total well-being was assessed using a Visual Analogue Scale with 62% of patients during add-on therapy and 60% in lamotrigine monotherapy reporting improvement in scores. Lamotrigine was generally well tolerated. Treatment was discontinued in 7% because of adverse events. In conclusion, lamotrigine is an effective AED in add-on therapy and monotherapy, it is safe and well tolerated, and successful conversion from add-on to monotherapy can be achieved in many cases. An additive effect between lamotrigine and valproate was observed.

Management of epilepsy in adolescents and adults

Epilepsy is the most common serious neurological disorder affecting an estimated 50 million people worldwide. Particular focus should be placed on a safe diagnosis, seizure and syndrome classification, and choice of pharmacological and surgical options for a range of patient populations with different health-care requirements. Eight new antiepileptic drugs were licensed in the 1990s with more to come. These new drugs along with earlier resective surgery have led to a better outcome for many more people with this condition.

Improving the epilepsy service: the role of the specialist nurse

There is currently a wide variation in the level of service provided for patients with epilepsy across the UK. Evidence is becoming available to suggest that improvements in local service provision may be achieved through the intervention of a specialist nurse. Using practical examples, this article explores the roles of the epilepsy specialist nurse, and examines how they may benefit patients and improve services. Functions such as liaison, patient assessment and management, counselling, provision of information, education, and audit are considered. It is hoped that the improved co-ordination and management of epilepsy services, that is achieved through specialist nurse intervention, will lead to improved patient outcomes and increased cost-effectiveness.

How much risk does a woman with active epilepsy pose to her newborn child in the puerperium? A pilot study

Much attention in the literature has recently been paid to women's issues in epilepsy but most of the literature stops in the delivery room or at the first moment of suckling. Although it is commonly supposed that a woman who continues to have active epilepsy during the puerperium will pose a risk to her child, little assessment of how great a risk this is has been carried out. We present an audit of the puerperal experiences of 187 women with epilepsy counselled before birth in our women's clinic and contrast this with a number of women with epilepsy seen for the first time in the puerperium (and therefore uncounselled). The audit suggests that in counselled women the risk is very low (women with Juvenile Myoclonic Epilepsy may be particularly at risk, as may women with tonic-clonic seizures that occur without warning, plus those with automatisms or who have prolonged post-ictal confusion). Some women with controlled epilepsy prior to conception may lose that control during the puerperium so even women with well controlled epilepsy should adopt precautions in the puerperium. The only baby to die (or be seriously injured) in the puerperium born to a woman with epilepsy was killed in the mother's first seizure.

Proactive pre-conception counselling for women with epilepsy-is it effective?

We describe the development of a proactive pre-conception counselling service for women with epilepsy based on complete re-investigation of the woman's epilepsy, a policy of withdrawing antiepileptic drugs (AEDs) thought to carry an increased risk of foetal abnormality (and substitution, where indicated, of AEDs thought to carry a lesser risk) and the exhibition of folic acid 5 mg daily plus fulfilment of the woman's educational needs and exploration of her and her partner's wishes. The outcome of the assessment of 90 such women is compared with the outcome of 59 women presenting to our service already pregnant. An audit of the outcomes in the two groups suggests that re-investigation of women pre-conceptually is worthwhile (some women turn out not to have epilepsy or have cerebral lesions best managed before pregnancy) and that foetal morbidity may be reduced by judicious rationalization of medication: folic acid taken before conception may also be protective for the foetus. Proactive pre-conception counselling, however, only works if the woman is prepared to wait (sometimes up to a year) for necessary drug changes to be instituted and is using reliable contraception.