Australian pregnancy registry of women taking antiepileptic drugs

Monotherapy treatment of epilepsy in pregnancy: congenital malformation outcomes in the child

BACKGROUND

Prenatal exposure to certain anti-seizure medications (ASMs) is associated with an increased risk of major congenital malformations (MCM). The majority of women with epilepsy continue taking ASMs throughout pregnancy and, therefore, information on the potential risks associated with ASM treatment is required.

OBJECTIVES

To assess the effects of prenatal exposure to ASMs on the prevalence of MCM in the child.

SEARCH METHODS

For the latest update of this review, we searched the following databases on 17 February 2022: Cochrane Register of Studies (CRS Web), MEDLINE (Ovid, 1946 to February 16, 2022), SCOPUS (1823 onwards), and ClinicalTrials.gov, WHO International Clinical Trials Registry Platform (ICTRP). No language restrictions were imposed.

SELECTION CRITERIA

We included prospective cohort controlled studies, cohort studies set within pregnancy registries, randomised controlled trials and epidemiological studies using routine health record data. Participants were women with epilepsy taking ASMs; the two control groups were women without epilepsy and untreated women with epilepsy.

DATA COLLECTION AND ANALYSIS

Five authors independently selected studies for inclusion. Eight authors completed data extraction and/or risk of bias assessments. The primary outcome was the presence of an MCM. Secondary outcomes included specific types of MCM. Where meta-analysis was not possible, we reviewed included studies narratively.

MAIN RESULTS

From 12,296 abstracts, we reviewed 283 full-text publications which identified 49 studies with 128 publications between them. Data from ASM-exposed pregnancies were more numerous for prospective cohort studies (n = 17,963), than data currently available for epidemiological health record studies (n = 7913). The MCM risk for children of women without epilepsy was 2.1% (95% CI 1.5 to 3.0) in cohort studies and 3.3% (95% CI 1.5 to 7.1) in health record studies. The known risk associated with sodium valproate exposure was clear across comparisons with a pooled prevalence of 9.8% (95% CI 8.1 to 11.9) from cohort data and 9.7% (95% CI 7.1 to 13.4) from routine health record studies. This was elevated across almost all comparisons to other monotherapy ASMs, with the absolute risk differences ranging from 5% to 9%. Multiple studies found that the MCM risk is dose-dependent. Children exposed to carbamazepine had an increased MCM prevalence in both cohort studies (4.7%, 95% CI 3.7 to 5.9) and routine health record studies (4.0%, 95% CI 2.9 to 5.4) which was significantly higher than that for the children born to women without epilepsy for both cohort (RR 2.30, 95% CI 1.47 to 3.59) and routine health record studies (RR 1.14, 95% CI 0.80 to 1.64); with similar significant results in comparison to the children of women with untreated epilepsy for both cohort studies (RR 1.44, 95% CI 1.05 to 1.96) and routine health record studies (RR 1.42, 95% CI 1.10 to 1.83). For phenobarbital exposure, the prevalence was 6.3% (95% CI 4.8 to 8.3) and 8.8% (95% CI 0.0 to 9277.0) from cohort and routine health record data, respectively. This increased risk was significant in comparison to the children of women without epilepsy (RR 3.22, 95% CI 1.84 to 5.65) and those born to women with untreated epilepsy (RR 1.64, 95% CI 0.94 to 2.83) in cohort studies; data from routine health record studies was limited. For phenytoin exposure, the prevalence of MCM was elevated for cohort study data (5.4%, 95% CI 3.6 to 8.1) and routine health record data (6.8%, 95% CI 0.1 to 701.2). The prevalence of MCM was higher for phenytoin-exposed children in comparison to children of women without epilepsy (RR 3.81, 95% CI 1.91 to 7.57) and the children of women with untreated epilepsy (RR 2.01. 95% CI 1.29 to 3.12); there were no data from routine health record studies. Pooled data from cohort studies indicated a significantly increased MCM risk for children exposed to lamotrigine in comparison to children born to women without epilepsy (RR 1.99, 95% CI 1.16 to 3.39); with a risk difference (RD) indicating a 1% increased risk of MCM (RD 0.01. 95% CI 0.00 to 0.03). This was not replicated in the comparison to the children of women with untreated epilepsy (RR 1.04, 95% CI 0.66 to 1.63), which contained the largest group of lamotrigine-exposed children (> 2700). Further, a non-significant difference was also found both in comparison to the children of women without epilepsy (RR 1.19, 95% CI 0.86 to 1.64) and children born to women with untreated epilepsy (RR 1.00, 95% CI 0.79 to 1.28) from routine data studies. For levetiracetam exposure, pooled data provided similar risk ratios to women without epilepsy in cohort (RR 2.20, 95% CI 0.98 to 4.93) and routine health record studies (RR 0.67, 95% CI 0.17 to 2.66). This was supported by the pooled results from both cohort (RR 0.71, 95% CI 0.39 to 1.28) and routine health record studies (RR 0.82, 95% CI 0.39 to 1.71) when comparisons were made to the offspring of women with untreated epilepsy. For topiramate, the prevalence of MCM was 3.9% (95% CI 2.3 to 6.5) from cohort study data and 4.1% (0.0 to 27,050.1) from routine health record studies. Risk ratios were significantly higher for children exposed to topiramate in comparison to the children of women without epilepsy in cohort studies (RR 4.07, 95% CI 1.64 to 10.14) but not in a smaller comparison to the children of women with untreated epilepsy (RR 1.37, 95% CI 0.57 to 3.27); few data are currently available from routine health record studies. Exposure in utero to topiramate was also associated with significantly higher RRs in comparison to other ASMs for oro-facial clefts. Data for all other ASMs were extremely limited. Given the observational designs, all studies were at high risk of certain biases, but the biases observed across primary data collection studies and secondary use of routine health records were different and were, in part, complementary. Biases were balanced across the ASMs investigated, and it is unlikely that the differential results observed across the ASMs are solely explained by these biases.

AUTHORS' CONCLUSIONS

Exposure in the womb to certain ASMs was associated with an increased risk of certain MCMs which, for many, is dose-dependent.

Anti-seizure therapy with a long-term, implanted intra-cerebroventricular delivery system for drug-resistant epilepsy: A first-in-man study

BACKGROUND

A clinical feasibility study was undertaken at a single center of long-term intra-cerebroventricular drug delivery of the anti-seizure medication valproic acid, into the cerebrospinal fluid (CSF) in order to treat drug resistant focal seizures, using an implantable infusion system. The primary objective was to establish the dose range of VPA administered in this manner. Secondarily, safety, pharmacokinetics (PK) and a preliminary estimate of effectiveness were evaluated.

METHODS

In this single arm study, five adult subjects, with 29-234 focal onset seizures per month from a seizure focus involving the mesial temporal lobe were implanted with the system (clinicaltrials.gov identifier NCT02899611). Oral valproic acid (VPA) had previously been ineffective in all subjects. Post-surgery, pharmacokinetic studies of CSF infused VPA were performed. Valproic acid doses were increased stepwise in a standardised protocol.

FINDINGS

The procedure and implantation were well-tolerated by all subjects. Four subjects responded with > 50% seizure reduction at the highest tested dose of 160 mg/day. Two subjects experienced extended periods of complete seizure freedom. All five subjects reported significant quality of life improvement. No clinical dose limiting side effects were encountered and there was no evidence of local periventricular toxicity in three subjects who were evaluated with imaging (T2 MRI). Side effects included nausea and appetite loss but were not dose-limiting. Mean CSF valproic acid levels were 45 μg per ml (range 20-120 μg per ml), with corresponding serum levels of 4-14 μg per ml.  Subjects have received therapy for up to 2.5 years in total . The efficacy analysis presented focuses on the period of time with the current pump with a mean 12.5 months, range 11.5-15 months. Pump failure requiring reimplantation was a significant initial issue in all subjects but resolved with use of pumps suitably compatible with long-term exposure to valproic acid.

INTERPRETATION

The study demonstrated that chronic intraventricular administration of valproic acid is safe and effective in subjects with medically refractory epilepsy over many months. The procedure for implanting the infusion system is safe and well-tolerated. High CSF levels are achieved with corresponding low serum levels and this therapy is shown to be effective despite unsuccessful earlier use of oral valproate preparations. Drug side effects were minimal.

FUNDING

The study was funded by Cerebral Therapeutics Inc., Suite 137 12635 East Montview Blvd Aurora CO 80045.

Monotherapy treatment of epilepsy in pregnancy: congenital malformation outcomes in the child

BACKGROUND

There is evidence that certain antiepileptic drugs (AEDs) are teratogenic and are associated with an increased risk of congenital malformation. The majority of women with epilepsy continue taking AEDs throughout pregnancy; therefore it is important that comprehensive information on the potential risks associated with AED treatment is available.

OBJECTIVES

To assess the effects of prenatal exposure to AEDs on the prevalence of congenital malformations in the child.

SEARCH METHODS

We searched the Cochrane Epilepsy Group Specialized Register (September 2015), Cochrane Central Register of Controlled Trials (CENTRAL) (2015, Issue 11), MEDLINE (via Ovid) (1946 to September 2015), EMBASE (1974 to September 2015), Pharmline (1978 to September 2015), Reprotox (1983 to September 2015) and conference abstracts (2010-2015) without language restriction.

SELECTION CRITERIA

We included prospective cohort controlled studies, cohort studies set within pregnancy registries and randomised controlled trials. Participants were women with epilepsy taking AEDs; the two control groups were women without epilepsy and women with epilepsy who were not taking AEDs during pregnancy.

DATA COLLECTION AND ANALYSIS

Three authors independently selected studies for inclusion. Five authors completed data extraction and risk of bias assessments. The primary outcome was the presence of a major congenital malformation. Secondary outcomes included specific types of major congenital malformations. Where meta-analysis was not possible, we reviewed included studies narratively.

MAIN RESULTS

We included 50 studies, with 31 contributing to meta-analysis. Study quality varied, and given the observational design, all were at high risk of certain biases. However, biases were balanced across the AEDs investigated and we believe that the results are not explained by these biases.Children exposed to carbamazepine (CBZ) were at a higher risk of malformation than children born to women without epilepsy (N = 1367 vs 2146, risk ratio (RR) 2.01, 95% confidence interval (CI) 1.20 to 3.36) and women with untreated epilepsy (N = 3058 vs 1287, RR 1.50, 95% CI 1.03 to 2.19). Children exposed to phenobarbital (PB) were at a higher risk of malformation than children born to women without epilepsy (N = 345 vs 1591, RR 2.84, 95% CI 1.57 to 5.13). Children exposed to phenytoin (PHT) were at an increased risk of malformation compared with children born to women without epilepsy (N = 477 vs 987, RR 2.38, 95% CI 1.12 to 5.03) and to women with untreated epilepsy (N = 640 vs 1256, RR 2.40, 95% CI 1.42 to 4.08). Children exposed to topiramate (TPM) were at an increased risk of malformation compared with children born to women without epilepsy (N = 359 vs 442, RR 3.69, 95% CI 1.36 to 10.07). The children exposed to valproate (VPA) were at a higher risk of malformation compared with children born to women without epilepsy (N = 467 vs 1936, RR 5.69, 95% CI 3.33 to 9.73) and to women with untreated epilepsy (N = 1923 vs 1259, RR 3.13, 95% CI 2.16 to 4.54). There was no increased risk for major malformation for lamotrigine (LTG). Gabapentin (GBP), levetiracetam (LEV), oxcarbazepine (OXC), primidone (PRM) or zonisamide (ZNS) were not associated with an increased risk, however, there were substantially fewer data for these medications.For AED comparisons, children exposed to VPA had the greatest risk of malformation (10.93%, 95% CI 8.91 to 13.13). Children exposed to VPA were at an increased risk of malformation compared with children exposed to CBZ (N = 2529 vs 4549, RR 2.44, 95% CI 2.00 to 2.94), GBP (N = 1814 vs 190, RR 6.21, 95% CI 1.91 to 20.23), LEV (N = 1814 vs 817, RR 5.82, 95% CI 3.13 to 10.81), LTG (N = 2021 vs 4164, RR 3.56, 95% CI 2.77 to 4.58), TPM (N = 1814 vs 473, RR 2.35, 95% CI 1.40 to 3.95), OXC (N = 676 vs 238, RR 3.71, 95% CI 1.65 to 8.33), PB (N = 1137 vs 626, RR 1.59, 95% CI 1.11 to 2.29, PHT (N = 2319 vs 1137, RR 2.00, 95% CI 1.48 to 2.71) or ZNS (N = 323 vs 90, RR 17.13, 95% CI 1.06 to 277.48). Children exposed to CBZ were at a higher risk of malformation than those exposed to LEV (N = 3051 vs 817, RR 1.84, 95% CI 1.03 to 3.29) and children exposed to LTG (N = 3385 vs 4164, RR 1.34, 95% CI 1.01 to 1.76). Children exposed to PB were at a higher risk of malformation compared with children exposed to GBP (N = 204 vs 159, RR 8.33, 95% CI 1.04 to 50.00), LEV (N = 204 vs 513, RR 2.33, 95% CI 1.04 to 5.00) or LTG (N = 282 vs 1959, RR 3.13, 95% CI 1.64 to 5.88). Children exposed to PHT had a higher risk of malformation than children exposed to LTG (N = 624 vs 4082, RR 1.89, 95% CI 1.19 to 2.94) or to LEV (N = 566 vs 817, RR 2.04, 95% CI 1.09 to 3.85); however, the comparison to LEV was not significant in the random-effects model. Children exposed to TPM were at a higher risk of malformation than children exposed to LEV (N = 473 vs 817, RR 2.00, 95% CI 1.03 to 3.85) or LTG (N = 473 vs 3975, RR 1.79, 95% CI 1.06 to 2.94). There were no other significant differences, or comparisons were limited to a single study.We found significantly higher rates of specific malformations associating PB exposure with cardiac malformations and VPA exposure with neural tube, cardiac, oro-facial/craniofacial, and skeletal and limb malformations in comparison to other AEDs. Dose of exposure mediated the risk of malformation following VPA exposure; a potential dose-response association for the other AEDs remained less clear.

AUTHORS' CONCLUSIONS

Exposure in the womb to certain AEDs carried an increased risk of malformation in the foetus and may be associated with specific patterns of malformation. Based on current evidence, LEV and LTG exposure carried the lowest risk of overall malformation; however, data pertaining to specific malformations are lacking. Physicians should discuss both the risks and treatment efficacy with the patient prior to commencing treatment.

Epilepsy during pregnancy: focus on management strategies

In the US, more than one million women with epilepsy are of childbearing age and have over 20,000 babies each year. Patients with epilepsy who become pregnant are at risk of complications, including changes in seizure frequency, maternal morbidity and mortality, and congenital anomalies due to antiepileptic drug exposure. Appropriate management of epilepsy during pregnancy may involve frequent monitoring of antiepileptic drug serum concentrations, potential preconception switching of antiepileptic medications, making dose adjustments, minimizing peak drug concentration with more frequent dosing, and avoiding potentially teratogenic medications. Ideally, preconception planning will be done to minimize risks to both the mother and fetus during pregnancy. It is important to recognize benefits and risks of current and emerging therapies, especially with revised pregnancy labeling in prescription drug product information. This review will outline risks for epilepsy during pregnancy, review various recommendations from leading organizations, and provide an evidence-based approach for managing patients with epilepsy before, during, and after pregnancy.

Alteration of bioelectrically-controlled processes in the embryo: a teratogenic mechanism for anticonvulsants

Maternal use of anticonvulsants during the first trimester of pregnancy has been associated with an elevated risk of major congenital malformations in the offspring. Whether the increased risk is caused by the specific pharmacological mechanisms of certain anticonvulsants, the underlying epilepsy, or common genetic or environmental risk factors shared by epilepsy and malformations has been controversial. We hypothesize that anticonvulsant therapies during pregnancy that attain more successful inhibition of neurotransmission might lead to both better seizure control in the mother and stronger alteration of bioelectrically-controlled processes in the embryo that result in structural malformations. We propose that development of pharmaceuticals that do not alter cell resting transmembrane voltage levels could result in safer drugs.

Lamotrigine and its applications in the treatment of epilepsy and other neurological and psychiatric disorders

Lamotrigine is a broad-spectrum antiepileptic drug, initially approved in 1994 for the adjunctive treatment of partial seizures in adults and for the generalized seizures of Lennox-Gastaut syndrome in pediatric (>2 years old) and adult populations. Its role in the treatment of bipolar disorder type I has also been well established. In addition, lamotrigine has been successfully used for the management of other neurological conditions such as migraines and neuropathic pain, and preliminary data show promising results. It has favorable pharmacokinetic properties and is generally well tolerated. The small risk of serious skin rash can be minimized with slow titration of the drug and dose adjustment with concomitant medications. Lamotrigine has demonstrated particular benefit in the treatment of women and elderly patients with epilepsy.

Obstetric and birth outcomes in pregnant women with epilepsy: A hospital-based study

Introduction:

In addition to changes in seizure frequency, pregnant women with epilepsy (WWE) are at increased risk of complications during pregnancy or delivery. In the absence of a nationwide WWE registry, hospital-based studies may provide important information regarding current management and outcomes in these patients.

Objectives:

The aims of this study were to determine changes in seizure frequency, and pregnancy and birth outcomes among pregnant WWE.

Materials and Methods:

We conducted a retrospective review of medical records of pregnant patients with epilepsy, who obtained medical care (from 2006 to 2011) at one of the general hospitals in the North-Eastern State of Malaysia. Data were collected for seizure frequency before and during the pregnancy, concurrent medications, pregnancy complications, and neonatal outcomes.

Results:

We reviewed records of 25 patients with a total of 33 different pregnancies. All patients were treated with antiepileptic medications during their pregnancies, with 42% monotherapy and 58% polytherapy. Seizure frequency decreased in 5 (15.2%), increased in 18 (54.5%) and unchanged in 10 (30.3%) cases of pregnancies. Pregnancy complications were anemia, gestational diabetes mellitus, gestational hypertension, intrauterine growth retardation, premature rupture of membrane, and vaginal bleeding. Preterm deliveries were recorded in 11 (33.3%) infants.

Conclusion:

In our setting, many patients were being on polytherapy during their pregnancies. This underscores the need for planned pregnancies so that antiepileptic medications can be optimized prior to pregnancy.

Impact of early life exposure to antiepileptic drugs on neurobehavioral outcomes based on laboratory animal and clinical research

Epilepsy affects approximately 1% of children under the age of 15, making it a very common neurological disorder in the pediatric population (Russ et al., 2012). In addition, ~0.4-0.8% of all pregnant women have some form of epilepsy (Hauser et al., 1996a,b; Borthen et al., 2009; Krishnamurthy, 2012). Despite the potential deleterious effects of antiepileptic drugs (AEDs) on the developing brain, their use is still required for seizure control in pregnant women (Krishnamurthy, 2012), and they represent the standard approach for treating children with epilepsy (Chu-Shore and Thiele, 2010; Quach et al., 2010; Verrotti et al., 2011). Even when AEDs are effective, there are potential side effects, including cognitive and affective changes or altered sleep and appetite. The consequences of AED exposure in development have been studied extensively (Canger et al., 1999; Modi et al., 2011a,b; Oguni, 2011). Despite intensive study, there is still debate about the long-term consequences of early life AED exposure. Here, we consider the evidence to date that AED exposure, either prenatally or in early postnatal life, has significant adverse effects on the developing brain and incorporate studies of laboratory animals as well as those of patients. We also note the areas of research where greater clarity seems critical in order to make significant advances. A greater understanding of the impact of AEDs on somatic, cognitive and behavioral development has substantial value because it has the potential to inform clinical practice and guide studies aimed at understanding the genetic and molecular bases of comorbid pathologies associated with common treatment regimens. Understanding these effects has the potential to lead to AEDs with fewer side effects. Such advances would expand treatment options, diminish the risk associated with AED exposure in susceptible populations, and improve the quality of life and health outcomes of children with epilepsy and children born to women who took AEDs during pregnancy.

The Australian brain and cognition and antiepileptic drugs study: IQ in school-aged children exposed to sodium valproate and polytherapy

Prenatal exposure to sodium valproate (VPA) and polytherapy has been linked with increased risk of birth defects and cognitive impairment in young children. We evaluated the cognitive impact of prenatal exposure to VPA and polytherapy in school-aged children. Fifty-seven children exposed to VPA (n = 23), polytherapy with VPA (n = 15), or polytherapy without VPA (n = 19) were assessed using the Wechsler Intelligence Scale for Children--Fourth Edition. Information on maternal epilepsy, pregnancy, and medical history was obtained prospectively through the Australian Pregnancy Register for Women with Epilepsy and Allied Disorders. All groups had elevated frequencies of Extremely Low (<70) or Borderline (70-79) Full-Scale IQ (15.8-40.0%). Verbal Comprehension and Working Memory scores in all groups fell significantly below the standardized test mean, while Perceptual Reasoning and Processing Speed scores were relatively intact. Multivariate analysis of covariance analysis revealed significant main effects of VPA on Verbal Comprehension and Working Memory, and of polytherapy on Verbal Comprehension and Processing Speed. Our results suggest that VPA has a dose-dependent negative impact on verbal intellectual abilities, and may also affect working memory. The possibility that inclusion of VPA in many polytherapy regimens may underlie reduced mean scores of polytherapy-exposed children is discussed.

Epilepsy pharmacogenetics

Large interindividual variation in efficacy and adverse effects of anti-epileptic therapy presents opportunities and challenges in pharmacogenomics. Although the first true association of genetic polymorphism in drug-metabolizing enzymes with anti-epileptic drug dose was reported 10 years ago, most of the findings have had little impact on clinical practice so far. Most studies performed to date examined candidate genes and were focused on candidate gene selection. Genome-wide association and whole-genome sequencing technologies empower hypothesis-free comprehensive screening of genetic variation across the genome and now the main challenge remaining is to select and study clinically relevant phenotypes suitable for genetic studies. Here we review the current state of epilepsy pharmacogenetics focusing on phenotyping questions and discuss what characteristics we need to study to get answers.

Pregnancy outcomes in women with epilepsy: a systematic review and meta-analysis of published pregnancy registries and cohorts

PURPOSE

To conduct a systematic review and meta-analysis to quantify the incidence of congenital malformations (CMs) and other pregnancy outcomes as a function of in utero anti-epileptic drug (AED) exposure.

METHODS

We performed a systematic literature review to identify all published registries and cohort studies of births from pregnant women with epilepsy (WWE) that reported incidence of CMs. Overall incidences were calculated using a random effects model.

RESULTS

The review included 59 studies that met inclusion/exclusion criteria, involving 65,533 pregnancies in WWE and 1,817,024 in healthy women. The calculated incidence of births with CM in WWE [7.08%; 95% CIs 5.62, 8.54] was higher than healthy women [2.28%; CIs 1.46, 3.10]. Incidence was highest for AED polytherapy [16.78%; CIs 0.51, 33.05]. The AED with the highest CM incidence was valproate, which was 10.73% [CIs 8.16, 13.29] for valproate monotherapy.

CONCLUSIONS

Results of this systematic literature review suggest that the overall incidence of CMs in children born of WWE is approximately threefold that of healthy women. The risk is elevated for all AED monotherapy and further elevated for AED polytherapy compared to women without epilepsy. The risk was significantly higher for children exposed to valproate monotherapy and to polytherapy of 2 or more drugs when the polytherapy combination included phenobarital, phenytoin, or valproate. Further research is needed to delineate the specific risk for each individual AED and to determine underlying mechanisms including genetic risk factors.

Preliminary findings from the National Register of Antipsychotic Medication in Pregnancy

OBJECTIVE

Following the presentation of a case study and an overview of current data highlighting the need for further research into the use of antipsychotic medication during pregnancy, the aim of the present paper was to outline the establishment of, and present preliminary data from, the National Register of Antipsychotic Medication in Pregnancy (NRAMP).

METHOD

Australian women with a history of psychosis, including schizophrenia, bipolar affective disorder with psychosis, schizoaffective disorder and first-episode psychosis, who are pregnant, are currently being invited to participate. The confluence of speculated national pregnancy rates and epidemiological data regarding child-bearing-age women with psychosis suggested an enrollment target of 100 women over a 24 month period. Details of antipsychotic medication are recorded throughout the pregnancy and for 1 year postnatally. Interviews with the mother are conducted 6 weekly antenatally, and then at 6 and 12 weeks, and 6 and 12 months postnatally, to assess symptoms of psychosis and depression, and attitudes towards parenting. In addition, consultations are conducted with the women's health-care providers to collate information regarding pharmacology and related side-effects, obstetric outcomes, psychiatric diagnoses and symptoms during pregnancy and for 1 year after delivery, and the provision of details on the baby's health and well-being.

RESULTS

NRAMP was launched in 2005. Ethics approvals have been gained at 14 sites nationally. Thirty women have consented, and 11 have completed. Data including demographics, health-care provision and medication for the first 30 participants are presented.

CONCLUSIONS

The establishment of NRAMP is an important strategy in improving the management of serious mental illness such as schizophrenia and related disorders, in women who are pregnant. This project involves extensive collaboration between many different clinical groups and industry, and shall culminate in an important resource to improve the quality of life for both patients and future generations.

Use of phenytoin, phenobarbital, or diazepam during pregnancy and risk of congenital abnormalities: a case-time-control study

PURPOSE

Case-control studies are often used to examine putative teratogenic drug effects during organogenesis but these studies are subject to confounding by indication, recall, and participation bias. The case-time-control approach is less susceptible to these sources of bias. We studied congenital abnormalities following exposure to phenytoin, phenobarbital, and diazepam in early pregnancy, i.e., second and third month, compared to mid-pregnancy, i.e., fifth and sixth month of pregnancy.

METHODS

We analyzed data from the Hungarian Case-Control Surveillance of Congenital Abnormalities (1980-1996) in a case-time-control study.

RESULTS

The study included 22 843 children with congenital abnormalities (cases) and 38 151 children with no abnormalities (controls). Overall, odds ratio (OR) for congenital abnormalities after exposure to one of the three drugs in early pregnancy was 1.2 (95% confidence interval (CI): 1.0-1.4). Among children exposed to phenytoin OR for congenital abnormalities was 3.7 (95%CI: 0.3-49.6), for children exposed to phenobarbital the OR was 1.1 (95%CI 0.7-1.7), and for diazepam, OR for congenital abnormalities was 1.2 (95%CI: 1.0-1.4).

CONCLUSIONS

The associations we found between the drugs examined and congenital abnormalities were either only borderline significant or not statistically significant. The case-time-control study provides an interesting way of using existing case-control data to study rare side effect of drugs taken during pregnancy.

[EURAP: the European Registry of Antiepileptic Drugs and Pregnancy]

All old-generation antiepileptic drugs (AEDs) are considered to be teratogenic. In Germany, one out of 200 pregnant women (0.5%) is treated with AEDs for epilepsy. The risk of major malformations following exposure to AEDs during the first trimester of pregnancy is two to three times the rate reported in the general population, which is estimated at 2-3%. The risks associated with the treatment of epilepsy during pregnancy are therefore of major concern to all women of childbearing potential with epilepsy. Data on the comparative teratogenicity of these AEDs in humans are, however, conflicting, mainly due to inadequate sample sizes and other methodological shortcomings of previous studies. The teratogenic potential of newer AEDs is even less well known, which prevents a rational approach to AED treatment in women of childbearing potential. The European Registry of Antiepileptic Drugs and Pregnancy is a prospective international multicentre study of pregnancies with AEDs. In Germany the project was started in 2001 and so far more than 500 pregnancies have been enrolled. The enrollment rate is 4% of 4,000 pregnancies with AEDs reported annually.

Role of valproate across the ages. Treatment of epilepsy in adults

A workshop was held in Göteborg in June 2005 to discuss the place of valproate in treating adult epilepsies. Consensus positions were developed on the epilepsy types for which the drug is most suitable and the use of valproate in women of child-bearing age, in men and in patients with psychiatric comorbidity. Valproate was considered to be effective across a broad variety of epilepsy syndromes and seizure types and should be considered a suitable choice for first-line monotherapy of juvenile myoclonic epilepsy and other idiopathic generalized epilepsies. The use of valproate by women of child-bearing age is associated with potential harm to the foetus. A conservative approach to treatment is recommended in these patients whereby alternative antiepileptic drugs should be proposed to women planning pregnancies wherever satisfactory seizure control can be thereby maintained. In cases where valproate is used during pregnancy, either because the pregnancy was unplanned or because alternative treatment options of equivalent efficacy are unavailable, appropriate counselling, precautionary measures and monitoring should be provided. The evidence for an impact of valproate on male reproductive health is equivocal and considerations of male fertility should not be taken into account in deciding whether to prescribe valproate to men. Valproate can be proposed safely to patients with comorbid psychiatric disease or underlying psychiatric vulnerability.

Role of valproate across the ages. Treatment of epilepsy in children

In June 2005 a team of experts participated in a workshop with the objective of reaching agreement on the place of valproate use in the treatment of paediatric epilepsy patients. A general "consensus of the meeting" was that the initiation of antiepileptic drug (AED) treatment should be based on a seizure-syndromic approach in children. Participants of the meeting also agreed that valproate is currently the AED with the broadest spectrum across all types of seizures and syndromes. Its superiority has been shown over almost 40 years of clinical experience. The best results are seen in idiopathic generalized epilepsy with or without photosensitivity, idiopathic focal and symptomatic generalized tonic-clonic seizures (GTCS). Evidence supports the use of valproate, ethosuximide and lamotrigine in absence epilepsies and the use of carbamazepine, lamotrigine, oxcarbazepine, phenytoin, topiramate, valproate and phenobarbital for primary GTCS. For new AEDs trials have been undertaken to define their therapeutic role but studies comparing their role to 'old' broad-spectrum drugs in specific syndromes are missing. Experts concluded that intravenous (i.v.) valproate is a useful agent in the treatment of non-convulsive status epilepticus (SE). There is an easy transition to oral treatment following i.v. valproate use. The discussion also concluded that, despite the lack of studies, valproate is an interesting, underutilized alternative in convulsive SE but more controlled studies are needed. The side effects of valproate use are well documented. Its effect on cognition and behaviour is more favourable than many of the other AEDs which is an important consideration in children. Overall, the clinical consensus of the meeting was that valproate's well established therapeutic properties far outweigh the negative side effects. Contraindication or withdrawal should be assessed individually.

Management of epilepsy in women of childbearing age: practical recommendations

Women with epilepsy should not be discouraged from becoming pregnant as the likelihood of having a healthy baby is very high. However, in such women, early and individualised counselling about pregnancy and contraception is essential. Ideally, pregnancies should be planned, folic acid (5 mg/day) given and antiepileptic drug (AED) treatment optimised well before conception to ensure that the lowest dosage that controls seizures is administered. When initiating AEDs in a woman of childbearing age, the most appropriate drug for the seizure type and syndrome should be chosen, although it is preferable to avoid valproate, because of a possible elevated risk of fetal malformations, when equi-effective agents are available for a given syndrome. In women who become pregnant while taking AEDs, fetal monitoring should include high-resolution ultrasonography before week 20 and measurement of serum alpha-fetoprotein levels. Amniocentesis is not routinely indicated. The measurement of blood concentrations of AEDs can be useful to ensure that the lowest possible maintenance dosage is being used, especially for those drugs whose pharmacokinetics are likely to change during pregnancy. Breastfeeding should be encouraged whatever the treatment administered.

Prophylactic treatment of bipolar disorder in pregnancy and breastfeeding: focus on emerging mood stabilizers

OBJECTIVES

Bipolar disorders are reported to have a high incidence during childbearing years and the need may arise to start or continue a pharmacological treatment during pregnancy and the postpartum period. In the last few years several investigations have evaluated the efficacy of emerging mood-stabilizing agents in the treatment of bipolar disorders, such as lamotrigine, olanzapine, risperidone, quetiapine, aripiprazole and ziprasidone. A number of studies, which examined the use of oxcarbazepine, point to its potential usefulness in prophylactic treatment. The aim of this review is to compare information from the literature on the safety of lamotrigine, oxcarbazepine, risperidone, olanzapine, and quetiapine to the safety data on classic mood stabilizers during pregnancy and the postpartum period.

METHODS

A computerized search carried out from 1980 to April 5, 2006 led to the summarization of the results. (References were updated after acceptance and prior to publication.)

RESULTS

Emerging mood stabilizers show uncertain safety parameters in pregnancy and lactation. Limited information on lamotrigine and oxcarbazepine does not suggest a clear increase in teratogenicity, while olanzapine appears to be associated with a higher risk of metabolic complications in pregnant women. Data about risperidone and quetiapine are still inconclusive. Finally, the literature on the safety of these compounds in breastfeeding is anecdotal.

CONCLUSIONS

Untreated pregnant bipolar women are at an increased risk of poor obstetrical outcomes and relapse of affective symptoms. On the other hand, classic antiepileptic drugs are well-known human teratogens, whereas data on lithium are partially ambiguous. The safety of emerging mood stabilizers in pregnancy and breastfeeding has not been examined extensively. Therefore, when approaching bipolar disorder, if possible, each episode must be considered separately.

Management of epilepsy in pregnancy

Pregnancies in women with epilepsy need careful management, by both the medical and obstetric teams, owing to the increased incidence of complications and adverse outcomes of pregnancy. By the time a pregnant woman with epilepsy presents, the major fetal organs are significantly formed, apart from the brain, and the development of which may be impaired by the maternal intake of valproate. Women of child-bearing age need to be counseled and told to seek advice regarding their anticonvulsant antiepileptic drug (AED) therapy, should they wish to become pregnant. All major AEDs are teratogenic, but the main risk to the developing fetus appears to be when the mother is on polytherapy, especially if sodium valproate forms part of the combination. Other issues that need to be discussed include the methods and consequences of prenatal screening, genetics of seizure disorder, folic acid and vitamin K supplements, labor, breast feeding and care and safety of the child.

Community-based, prospective, controlled study of obstetric and neonatal outcome of 179 pregnancies in women with epilepsy

PURPOSE

This study evaluated obstetric and neonatal outcome in a community-based cohort of women with active epilepsy (WWAE) compared with the general pregnant population receiving modern obstetric care.

METHODS

We reviewed the total population who gave birth between January 1989 and October 2000 at Kuopio University Hospital. Obstetric, demographic, and epilepsy data were collected prospectively from 179 singleton pregnancies of women with epilepsy and from 24,778 singleton pregnancies of unaffected controls. The obstetric data from the pregnancy register was supplemented with detailed neurologic data retrieved from the medical records. The data retrieved were comprehensive because of a follow-up strategy according to a predecided protocol.

RESULTS

During pregnancy, the seizure frequency was unchanged, or the change was for the better in the majority (83%) of the patients. We found no significant differences between WWAE and controls in the incidence of preeclampsia, preterm labor, or in the rates of caesarean sections, perinatal mortality, or low birth weight. However, the rate of small-for-gestational-age infants was significantly higher, and the head circumference was significantly smaller in WWAE. Apgar score at 1 min was lower in children of WWAE, and the need for care in the neonatal ward and neonatal intensive care were increased as compared with controls. The frequency of major malformations was 4.8% (-0.6-10.2%; 95% confidence interval) in the 127 children of WWAE.

CONCLUSIONS

Pregnancy course is uncomplicated and neonatal outcome is good in the majority of cases when a predecided protocol is used for the follow-up of WWAE in antenatal and neurologic care. Long-term follow-up of the neurologic and cognitive development of the children of WWAE is still needed.

Therapy Insight: clinical management of pregnant women with epilepsy

In pregnant women with epilepsy who are being treated with antiepileptic drugs (AEDs), careful clinical management is vital because seizure frequency can change during pregnancy, and both seizure activity and AED treatment can have consequences for the developing fetus. Complications of epilepsy and AED treatment include stillbirths, prematurity, low birth weight, major and minor malformations, and cognitive delay later in life. Certain AEDs probably have more adverse effects than others; data from prospective studies indicate that phenobarbital and valproate are associated with significant increases in major malformations, and retrospective studies show lower verbal IQs and greater need for extra assistance in school for children whose mothers received valproate during pregnancy. Monitoring of AED levels and dosage adjustment are warranted throughout pregnancy, and vitamin K(1) at a dose of 10 mg/day should be given in the last month, particularly when cytochrome P450 enzyme-inducing AEDs are being administered. In the postpartum period, breastfeeding is recommended; however, there is differential transfer of individual AEDs in breast milk, and the infant should be observed clinically. For all women of reproductive age, preconceptual counseling is important, and includes optimization of the AED regimen and advising the mother to take supplemental folic acid.

Adult epilepsy

The epilepsies are one of the most common serious brain disorders, can occur at all ages, and have many possible presentations and causes. Although incidence in childhood has fallen over the past three decades in developed countries, this reduction is matched by an increase in elderly people. Monogenic Mendelian epilepsies are rare. A clinical syndrome often has multiple possible genetic causes, and conversely, different mutations in one gene can lead to various epileptic syndromes. Most common epilepsies, however, are probably complex traits with environmental effects acting on inherited susceptibility, mediated by common variation in particular genes. Diagnosis of epilepsy remains clinical, and neurophysiological investigations assist with diagnosis of the syndrome. Brain imaging is making great progress in identifying the structural and functional causes and consequences of the epilepsies. Current antiepileptic drugs suppress seizures without influencing the underlying tendency to generate seizures, and are effective in 60-70% of individuals. Pharmacogenetic studies hold the promise of being able to better individualise treatment for each patient, with maximum possibility of benefit and minimum risk of adverse effects. For people with refractory focal epilepsy, neurosurgical resection offers the possibility of a life-changing cure. Potential new treatments include precise prediction of seizures and focal therapy with drug delivery, neural stimulation, and biological grafts.

Malformation risks of antiepileptic drugs in pregnancy: a prospective study from the UK Epilepsy and Pregnancy Register

OBJECTIVE

To assess the relative risk of major congenital malformation (MCM) from in utero exposure to antiepileptic drug (AEDs).

METHODS

Prospective data collected by the UK Epilepsy and Pregnancy Register were analysed. The presence of MCMs recorded within the first three months of life was the main outcome measure.

RESULTS

Full outcome data were collected on 3607 cases. The overall MCM rate for all AED exposed cases was 4.2% (95% confidence interval (CI), 3.6% to 5.0%). The MCM rate was higher for polytherapy (6.0%) (n = 770) than for monotherapy (3.7%) (n = 2598) (crude odds ratio (OR) = 1.63 (p = 0.010), adjusted OR = 1.83 (p = 0.002)). The MCM rate for women with epilepsy who had not taken AEDs during pregnancy (n = 239) was 3.5% (1.8% to 6.8%). The MCM rate was greater for pregnancies exposed only to valproate (6.2% (95% CI, 4.6% to 8.2%) than only to carbamazepine (2.2% (1.4% to 3.4%) (OR = 2.78 (p<0.001); adjusted OR = 2.97 (p<0.001)). There were fewer MCMs for pregnancies exposed only to lamotrigine than only to valproate. A positive dose response for MCMs was found for lamotrigine (p = 0.006). Polytherapy combinations containing valproate carried a higher risk of MCM than combinations not containing valproate (OR = 2.49 (1.31 to 4.70)).

CONCLUSIONS

Only 4.2% of live births to women with epilepsy had an MCM. The MCM rate for polytherapy exposure was greater than for monotherapy exposure. Polytherapy regimens containing valproate had significantly more MCMs than those not containing valproate. For monotherapy exposures, carbamazepine was associated with the lowest risk of MCM.

Valproic Acid in Epilepsy

Valproic acid (sodium valproate) is widely used as a first-line antiepileptic agent. As with many antiepileptic drugs, there are a number of consequences associated with the use of valproic acid in women of child-bearing potential. Most pregnancies have a favourable outcome in women with epilepsy, and these women should not be discouraged from becoming pregnant. Unlike many other antiepileptic drugs, valproic acid has no significant pharmacokinetic interactions with the steroid hormones used in oral contraceptives. During pregnancy, the major risks to mother and child result from loss of seizure control on the one hand, and an elevated risk of major congenital malformations due to antiepileptic drug treatment on the other. In particular, an elevated risk of major congenital malformations associated with valproic acid use has been a consistent finding in studies of patient registries and several large case series. In addition, developmental delay, characterised by low verbal IQ, has also been reported in children exposed to valproic acid in utero, although the relative risk is not precisely known. For these reasons, pregnancies in women being treated with valproic acid need to be planned, and the benefit-risk ratios associated with continuing valproic acid or changing treatment need to be discussed with the patient. When treatment with valproic acid is the most appropriate treatment to achieve optimal seizure control, a number of measures can be implemented to minimise risk to the fetus. These include the use of the lowest possible effective dose of valproic acid in monotherapy (ideally <1000 mg/day), appropriate folic acid supplementation and close antenatal monitoring. Regular counselling is a prerequisite for informed planning of pregnancies and optimisation of the probability of a healthy outcome. Future research on valproic acid and pregnancy should involve risk assessment in large, population-based prospective studies.

Teratogenicity of antiepileptic drugs: state of the art: review

PURPOSE OF REVIEW

Information on the risks associated with antiepileptic drug (AED) use in pregnancy is necessary for a rational approach to the management of women of childbearing potential who have epilepsy. This reviews addresses recent reports on the risk for birth defects and impaired postnatal development attributable to prenatal exposure to AEDs.

RECENT FINDINGS

Some studies have indicated greater risk for birth defects as well as for lower verbal IQ in association with exposure to valproic acid, as compared with some other AEDs. The risk appears to be greater at doses above 800-1000 mg/day; lower doses may not carry higher risks than those associated with other AEDs. This observation is a cause of concern but more data are needed from prospective studies to assess the possible impact of confounding factors in order to clarify whether there is a causal relationship. Large-scale pregnancy registries have been launched and are expected to provide more conclusive comparative data on the most frequently used AEDs in the near future.

SUMMARY

Although further studies are needed, it appears reasonable to use valproic acid with caution in women with epilepsy who are planning to become pregnant, and to consider prescribing other equally effective and safer AEDs if they are available. The importance of seizure control during pregnancy must not be neglected, and any attempt to change treatment should be done before conception. Drug withdrawal during pregnancy should be avoided, and patients should be made aware that definitive evidence on the relative safety of AEDs is lacking.

Using current evidence in selecting antiepileptic drugs for use during pregnancy

Children born to mothers taking antiepileptic drugs (AEDs) are at increased risk for findings of fetal anticonvulsant syndrome. Accepted treatment paradigms to minimize fetal risks include use of AED monotherapy and folic acid supplementation. However, as data are acquired from several ongoing pregnancy registries, differential risks among the various AED monotherapy regimens are being defined, further improving fetal outcomes.