Malformations in offspring of women with epilepsy: a prospective study

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.

Treatment and Management of Mental Health Conditions During Pregnancy and Postpartum: ACOG Clinical Practice Guideline No. 5

PURPOSE

To assess the evidence regarding safety and efficacy of psychiatric medications to treat mental health conditions during pregnancy and lactation. The conditions reviewed include depression, anxiety and anxiety-related disorders, bipolar disorder, and acute psychosis. For information on screening and diagnosis, refer to American College of Obstetricians and Gynecologists (ACOG) Clinical Practice Guideline Number 4, "Screening and Diagnosis of Mental Health Conditions During Pregnancy and Postpartum" (1).

TARGET POPULATION

Pregnant or postpartum individuals with mental health conditions with onset that may have predated the perinatal period or may have occurred for the first time in pregnancy or the first year postpartum or may have been exacerbated in that time.

METHODS

This guideline was developed using an a priori protocol in conjunction with a writing team consisting of one specialist in obstetrics and gynecology and one maternal-fetal medicine subspecialist appointed by the ACOG Committee on Clinical Practice Guidelines-Obstetrics and two external subject matter experts. ACOG medical librarians completed a comprehensive literature search for primary literature within Cochrane Library, Cochrane Collaboration Registry of Controlled Trials, EMBASE, PubMed, and MEDLINE. Studies that moved forward to the full-text screening stage were assessed by two authors from the writing team based on standardized inclusion and exclusion criteria. Included studies underwent quality assessment, and a modified GRADE (Grading of Recommendations Assessment, Development and Evaluation) evidence-to-decision framework was applied to interpret and translate the evidence into recommendation statements.

RECOMMENDATIONS

This Clinical Practice Guideline includes recommendations on treatment and management of perinatal mental health conditions including depression, anxiety, bipolar disorders, and acute postpartum psychosis, with a focus on psychopharmacotherapy. Recommendations are classified by strength and evidence quality. Ungraded Good Practice Points are included to provide guidance when a formal recommendation could not be made because of inadequate or nonexistent evidence.

Antiepileptic drug monotherapy for epilepsy: a network meta-analysis of individual participant data

BACKGROUND

This is an updated version of the original Cochrane Review published in 2017. Epilepsy is a common neurological condition with a worldwide prevalence of around 1%. Approximately 60% to 70% of people with epilepsy will achieve a longer-term remission from seizures, and most achieve that remission shortly after starting antiepileptic drug treatment. Most people with epilepsy are treated with a single antiepileptic drug (monotherapy) and current guidelines from the National Institute for Health and Care Excellence (NICE) in the United Kingdom for adults and children recommend carbamazepine or lamotrigine as first-line treatment for focal onset seizures and sodium valproate for generalised onset seizures; however, a range of other antiepileptic drug (AED) treatments are available, and evidence is needed regarding their comparative effectiveness in order to inform treatment choices.

OBJECTIVES

To compare the time to treatment failure, remission and first seizure of 12 AEDs (carbamazepine, phenytoin, sodium valproate, phenobarbitone, oxcarbazepine, lamotrigine, gabapentin, topiramate, eventrate, zonisamide, eslicarbazepine acetate, lacosamide) currently used as monotherapy in children and adults with focal onset seizures (simple focal, complex focal or secondary generalised) or generalised tonic-clonic seizures with or without other generalised seizure types (absence, myoclonus).

SEARCH METHODS

For the latest update, we searched the following databases on 12 April 2021: the Cochrane Register of Studies (CRS Web), which includes PubMed, Embase, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (ICTRP), the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Epilepsy Group Specialised Register and MEDLINE (Ovid, 1946 to April 09, 2021). We handsearched relevant journals and contacted pharmaceutical companies, original trial investigators and experts in the field.

SELECTION CRITERIA

We included randomised controlled trials of a monotherapy design in adults or children with focal onset seizures or generalised onset tonic-clonic seizures (with or without other generalised seizure types).

DATA COLLECTION AND ANALYSIS

This was an individual participant data (IPD) and network meta-analysis (NMA) review. Our primary outcome was 'time to treatment failure', and our secondary outcomes were 'time to achieve 12-month remission', 'time to achieve six-month remission', and 'time to first seizure post-randomisation'. We performed frequentist NMA to combine direct evidence with indirect evidence across the treatment network of 12 drugs. We investigated inconsistency between direct 'pairwise' estimates and NMA results via node splitting. Results are presented as hazard ratios (HRs) with 95% confidence intervals (CIs) and we assessed the certainty of the evidence using the CiNeMA approach, based on the GRADE framework. We have also provided a narrative summary of the most commonly reported adverse events.

MAIN RESULTS

IPD were provided for at least one outcome of this review for 14,789 out of a total of 22,049 eligible participants (67% of total data) from 39 out of the 89 eligible trials (43% of total trials). We could not include IPD from the remaining 50 trials in analysis for a variety of reasons, such as being unable to contact an author or sponsor to request data, data being lost or no longer available, cost and resources required to prepare data being prohibitive, or local authority or country-specific restrictions. No IPD were available from a single trial of eslicarbazepine acetate, so this AED could not be included in the NMA. Network meta-analysis showed high-certainty evidence that for our primary outcome, 'time to treatment failure', for individuals with focal seizures; lamotrigine performs better than most other treatments in terms of treatment failure for any reason and due to adverse events, including the other first-line treatment carbamazepine; HRs (95% CIs) for treatment failure for any reason for lamotrigine versus: eventrate 1.01 (0.88 to 1.20), zonisamide 1.18 (0.96 to 1.44), lacosamide 1.19 (0.90 to 1.58), carbamazepine 1.26 (1.10 to 1.44), oxcarbazepine 1.30 (1.02 to 1.66), sodium valproate 1.35 (1.09 to 1.69), phenytoin 1.44 (1.11 to 1.85), topiramate 1.50 (1.23 to 1.81), gabapentin 1.53 (1.26 to 1.85), phenobarbitone 1.97 (1.45 to 2.67). No significant difference between lamotrigine and eventrate was shown for any treatment failure outcome, and both AEDs seemed to perform better than all other AEDs. For people with generalised onset seizures, evidence was more limited and of moderate certainty; no other treatment performed better than first-line treatment sodium valproate, but there were no differences between sodium valproate, lamotrigine or eventrate in terms of treatment failure; HRs (95% CIs) for treatment failure for any reason for sodium valproate versus: lamotrigine 1.06 (0.81 to 1.37), eventrate 1.13 (0.89 to 1.42), gabapentin 1.13 (0.61 to 2.11), phenytoin 1.17 (0.80 to 1.73), oxcarbazepine 1.24 (0.72 to 2.14), topiramate 1.37 (1.06 to 1.77), carbamazepine 1.52 (1.18 to 1.96), phenobarbitone 2.13 (1.20 to 3.79), lacosamide 2.64 (1.14 to 6.09). Network meta-analysis also showed high-certainty evidence that for secondary remission outcomes, few notable differences were shown for either seizure type; for individuals with focal seizures, carbamazepine performed better than gabapentin (12-month remission) and sodium valproate (six-month remission). No differences between lamotrigine and any AED were shown for individuals with focal seizures, or between sodium valproate and other AEDs for individuals with generalised onset seizures. Network meta-analysis also showed high- to moderate-certainty evidence that, for 'time to first seizure,' in general, the earliest licensed treatments (phenytoin and phenobarbitone) performed better than the other treatments for individuals with focal seizures; phenobarbitone performed better than both first-line treatments carbamazepine and lamotrigine. There were no notable differences between the newer drugs (oxcarbazepine, topiramate, gabapentin, eventrate, zonisamide and lacosamide) for either seizure type. Generally, direct evidence (where available) and network meta-analysis estimates were numerically similar and consistent with confidence intervals of effect sizes overlapping. There was no important indication of inconsistency between direct and network meta-analysis results. The most commonly reported adverse events across all drugs were drowsiness/fatigue, headache or migraine, gastrointestinal disturbances, dizziness/faintness and rash or skin disorders; however, reporting of adverse events was highly variable across AEDs and across studies.

AUTHORS' CONCLUSIONS

High-certainty evidence demonstrates that for people with focal onset seizures, current first-line treatment options carbamazepine and lamotrigine, as well as newer drug eventrate, show the best profile in terms of treatment failure and seizure control as first-line treatments. For people with generalised tonic-clonic seizures (with or without other seizure types), current first-line treatment sodium valproate has the best profile compared to all other treatments, but lamotrigine and eventrate would be the most suitable alternative first-line treatments, particularly for those for whom sodium valproate may not be an appropriate treatment option. Further evidence from randomised controlled trials recruiting individuals with generalised tonic-clonic seizures (with or without other seizure types) is needed.

Seizure frequency and obstetric complications at advanced maternal age: a preliminary observational study in women with epilepsy

Background

Seizure control during pregnancy and obstetric outcomes are of important concerns for women with epilepsy (WWE) and their families. Advanced maternal age (≥35 years) shows a growing trend in the society with changes of lifestyle, which also occurs in diseased populations. The advanced maternal age is an independent factor for some unsatisfying obstetric outcomes. In this study we explored the seizure control and obstetric complications associated with advanced maternal age in WWE.

Methods

This study was based on the epilepsy pregnancy registry at West China Hospital. Patients with epilepsy in this registry who were aged 35 or older when starting pregnancy were included in this study. Their basic demographics and detailed information on epilepsy management and obstetric issues in all trimesters and during 1-year follow-up after birth were documented and reviewed. Data were processed by IBM SPSS version 22.0. The demographic characteristics, seizure frequency, treatment change, obstetric complications, and outcomes were analyzed and compared.

Results

Fifteen patients were included in this study, with an average age of 36.32 ± 2.39 years at pregnancy, and 73.33% of them were primiparas. The change of seizure frequency during pregnancy was not in a clear pattern, but there was an increased incidence of tonic-clonic seizures during the mid- and last trimesters. More than 20% of the patients had obstetric complications throughout the trimesters, including vaginal bleeding, hypothyroidism, and pre-eclampsia. The pre-eclampsia seemed extraordinarily complicated with other conditions. However, none of the complications were related with malformations or poor outcome of babies after 1-year follow-up.

Conclusion

Advanced maternal age combined with WWE is associated with frequent common obstetric complications. Future controlled studies with large sample sizes are needed to explore the related risks in comparison with other WWE and non-epileptic populations.

Zebrafish AC50 modelling: (Q)SAR models to predict developmental toxicity in zebrafish embryo

Developmental toxicity refers to the occurrence of adverse effects on a developing organism as a consequence of exposure to hazardous chemicals. The assessment of developmental toxicity has become relevant to the safety assessment process of chemicals. The zebrafish embryo developmental toxicology assay is an emerging test used to screen the teratogenic potential of chemicals and it is proposed as a promising test to replace teratogenic assays with animals. Supported by the increased availability of data from this test, the developmental toxicity assay with zebrafish has become an interesting endpoint for the in silico modelling. The purpose of this study was to build up quantitative structure-activity relationship (QSAR) models. In this work, new in silico models for the evaluation of developmental toxicity were built using a well-defined set of data from the ToxCast^TM Phase I chemical library on the zebrafish embryo. Categorical and continuous QSAR models were built by gradient boosting machine learning and the Monte Carlo technique respectively, in accordance with Organization for Economic Co-operation and Development principles and their statistical quality was satisfactory. The classification model reached balanced accuracy 0.89 and Matthews correlation coefficient 0.77 on the test set. The regression model reached correlation coefficient R² 0.70 in external validation and leave-one-out cross-validated Q² 0.73 in internal validation.

Phenytoin - An anti-seizure drug: Overview of its chemistry, pharmacology and toxicology

Phenytoin is a long-standing, anti-seizure drug widely used in clinical practice. It has also been evaluated in the context of many other illnesses in addition to its original epilepsy indication. The narrow therapeutic index of phenytoin and its ubiquitous daily use pose a high risk of poisoning. This review article focuses on the chemistry, pharmacokinetics, and toxicology of phenytoin, with a special focus on its mutagenicity, carcinogenicity, and teratogenicity. The side effects on human health associated with phenytoin use are thoroughly described. In particular, DRESS syndrome and cerebellar atrophy are addressed. This review will help in further understanding the benefits phenytoin use in the treatment of epilepsy.

Sodium valproate versus phenytoin monotherapy for epilepsy: an individual participant data review

BACKGROUND

Epilepsy is a common neurological condition in which abnormal electrical discharges from the brain cause recurrent unprovoked seizures. It is believed that with effective drug treatment up to 70% of individuals with active epilepsy have the potential to become seizure-free, and to go into long-term remission shortly after starting drug therapy with a single antiepileptic drug in monotherapy.Worldwide, sodium valproate and phenytoin are commonly used antiepileptic drugs for monotherapy treatment. It is generally believed that phenytoin is more effective for focal onset seizures, and that sodium pvalproate is more effective for generalised onset tonic-clonic seizures (with or without other generalised seizure types). This review is one in a series of Cochrane Reviews investigating pair-wise monotherapy comparisons. This is the latest updated version of the review first published in 2001, and updated in 2013 and 2016.

OBJECTIVES

To review the time to treatment failure, remission and first seizure of sodium valproate compared to phenytoin when used as monotherapy in people with focal onset seizures or generalised tonic-clonic seizures (with or without other generalised seizure types).

SEARCH METHODS

We searched the Cochrane Epilepsy Group's Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform ICTRP on 19 February 2018. We handsearched relevant journals, contacted pharmaceutical companies, original trial investigators and experts in the field.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing monotherapy with either sodium valproate or phenytoin in children or adults with focal onset seizures or generalised onset tonic-clonic seizures DATA COLLECTION AND ANALYSIS: This was an individual participant data (IPD) review. Our primary outcome was time to treatment failure and our secondary outcomes were time to first seizure post-randomisation, time to six-month, and 12-month remission, and incidence of adverse events. We used Cox proportional hazards regression models to obtain trial-specific estimates of hazard ratios (HRs) with 95% confidence intervals (CIs), using the generic inverse variance method to obtain the overall pooled HR and 95% CI.

MAIN RESULTS

We included 11 trials in this review and IPD were available for 669 individuals out of 1119 eligible individuals from five out of 11 trials, 60% of the potential data. Results apply to focal onset seizures (simple, complex and secondary generalised tonic-clonic seizures), and generalised tonic-clonic seizures, but not other generalised seizure types (absence or myoclonus seizure types). For remission outcomes, a HR of less than 1 indicates an advantage for phenytoin, and for first seizure and treatment failure outcomes a HR of less than 1 indicates an advantage for sodium valproate.The main overall results were: time to treatment failure for any reason related to treatment (pooled HR adjusted for seizure type 0.88, 95% CI 0.61 to 1.27; 5 studies; 528 participants; moderate-quality evidence), time to treatment failure due to adverse events (pooled HR adjusted for seizure type 0.77, 95% CI 0.44 to 1.37; 4 studies; 418 participants; moderate-quality evidence), time to treatment failure due to lack of efficacy (pooled HR for all participants 1.16 (95% CI 0.71 to 1.89; 5 studies; 451 participants; moderate-quality evidence). These results suggest that treatment failure for any reason related to treatment and treatment failure due to adverse events may occur earlier on phenytoin compared to sodium valproate, while treatment failure due to lack of efficacy may occur earlier on sodium valproate than phenytoin; however none of these results were statistically significant.Results for time to first seizure (pooled HR adjusted for seizure type 1.08, 95% CI 0.88 to 1.33; 5 studies; 639 participants; low-quality evidence) suggest that first seizure recurrence may occur slightly earlier on sodium valproate compared to phenytoin. There were no clear differences between drugs in terms of time to 12-month remission (pooled HR adjusted for seizure type 1.02, 95% CI 0.81 to 1.28; 4 studies; 514 participants; moderate-quality evidence) and time to six-month remission (pooled HR adjusted for seizure type 1.05, 95% CI 0.86 to 1.27; 5 studies; 639 participants; moderate-quality evidence).Limited information was available regarding adverse events in the trials and we could not make comparisons between the rates of adverse events on sodium valproate and phenytoin. Some adverse events reported with both drugs were drowsiness, rash, dizziness, nausea and gastrointestinal problems. Weight gain was also reported with sodium valproate and gingival hypertrophy/hyperplasia was reported on phenytoin.The methodological quality of the included trials was generally good, however four out of the five trials providing IPD for analysis were of an open-label design, therefore all results were at risk of detection bias. There was also evidence that misclassification of seizure type may have confounded the results of this review, particularly for the outcome 'time to first seizure' and heterogeneity was present in analysis of treatment failure outcomes which could not be explained by subgroup analysis by epilepsy type or by sensitivity analysis for misclassification of seizure type. Therefore, for treatment failure outcomes we judged the quality of the evidence to be moderate to low, for 'time to first seizure' we judged the quality of the evidence to be low, and for remission outcomes we judged the quality of the evidence to be moderate.

AUTHORS' CONCLUSIONS

We have not found evidence that a significant difference exists between valproate and phenytoin for any of the outcomes examined in this review. However detection bias, classification bias and heterogeneity may have impacted on the results of this review. We did not find any outright evidence to support or refute current treatment policies. We recommend that future trials be designed to the highest quality possible with consideration of masking, choice of population, classification of seizure type, duration of follow-up, choice of outcomes and analysis, and presentation of results.

Antiepileptic drug monotherapy for epilepsy: a network meta-analysis of individual participant data

BACKGROUND

Epilepsy is a common neurological condition with a worldwide prevalence of around 1%. Approximately 60% to 70% of people with epilepsy will achieve a longer-term remission from seizures, and most achieve that remission shortly after starting antiepileptic drug treatment. Most people with epilepsy are treated with a single antiepileptic drug (monotherapy) and current guidelines from the National Institute for Health and Care Excellence (NICE) in the United Kingdom for adults and children recommend carbamazepine or lamotrigine as first-line treatment for partial onset seizures and sodium valproate for generalised onset seizures; however a range of other antiepileptic drug (AED) treatments are available, and evidence is needed regarding their comparative effectiveness in order to inform treatment choices.

OBJECTIVES

To compare the time to withdrawal of allocated treatment, remission and first seizure of 10 AEDs (carbamazepine, phenytoin, sodium valproate, phenobarbitone, oxcarbazepine, lamotrigine, gabapentin, topiramate, levetiracetam, zonisamide) currently used as monotherapy in children and adults with partial onset seizures (simple partial, complex partial or secondary generalised) or generalised tonic-clonic seizures with or without other generalised seizure types (absence, myoclonus).

SEARCH METHODS

We searched the following databases: Cochrane Epilepsy's Specialised Register, CENTRAL, MEDLINE and SCOPUS, and two clinical trials registers. We handsearched relevant journals and contacted pharmaceutical companies, original trial investigators, and experts in the field. The date of the most recent search was 27 July 2016.

SELECTION CRITERIA

We included randomised controlled trials of a monotherapy design in adults or children with partial onset seizures or generalised onset tonic-clonic seizures (with or without other generalised seizure types).

DATA COLLECTION AND ANALYSIS

This was an individual participant data (IPD) review and network meta-analysis. Our primary outcome was 'time to withdrawal of allocated treatment', and our secondary outcomes were 'time to achieve 12-month remission', 'time to achieve six-month remission', 'time to first seizure post-randomisation', and 'occurrence of adverse events'. We presented all time-to-event outcomes as Cox proportional hazard ratios (HRs) with 95% confidence intervals (CIs). We performed pairwise meta-analysis of head-to-head comparisons between drugs within trials to obtain 'direct' treatment effect estimates and we performed frequentist network meta-analysis to combine direct evidence with indirect evidence across the treatment network of 10 drugs. We investigated inconsistency between direct estimates and network meta-analysis via node splitting. Due to variability in methods and detail of reporting adverse events, we have not performed an analysis. We have provided a narrative summary of the most commonly reported adverse events.

MAIN RESULTS

IPD was provided for at least one outcome of this review for 12,391 out of a total of 17,961 eligible participants (69% of total data) from 36 out of the 77 eligible trials (47% of total trials). We could not include IPD from the remaining 41 trials in analysis for a variety of reasons, such as being unable to contact an author or sponsor to request data, data being lost or no longer available, cost and resources required to prepare data being prohibitive, or local authority or country-specific restrictions.We were able to calculate direct treatment effect estimates for between half and two thirds of comparisons across the outcomes of the review, however for many of the comparisons, data were contributed by only a single trial or by a small number of participants, so confidence intervals of estimates were wide.Network meta-analysis showed that for the primary outcome 'Time to withdrawal of allocated treatment,' for individuals with partial seizures; levetiracetam performed (statistically) significantly better than current first-line treatment carbamazepine and other current first-line treatment lamotrigine performed better than all other treatments (aside from levetiracetam); carbamazepine performed significantly better than gabapentin and phenobarbitone (high-quality evidence). For individuals with generalised onset seizures, first-line treatment sodium valproate performed significantly better than carbamazepine, topiramate and phenobarbitone (moderate- to high-quality evidence). Furthermore, for both partial and generalised onset seizures, the earliest licenced treatment, phenobarbitone seems to perform worse than all other treatments (moderate- to high-quality evidence).Network meta-analysis also showed that for secondary outcomes 'Time to 12-month remission of seizures' and 'Time to six-month remission of seizures,' few notable differences were shown for either partial or generalised seizure types (moderate- to high-quality evidence). For secondary outcome 'Time to first seizure,' for individuals with partial seizures; phenobarbitone performed significantly better than both current first-line treatments carbamazepine and lamotrigine; carbamazepine performed significantly better than sodium valproate, gabapentin and lamotrigine. Phenytoin also performed significantly better than lamotrigine (high-quality evidence). In general, the earliest licenced treatments (phenytoin and phenobarbitone) performed better than the other treatments for both seizure types (moderate- to high-quality evidence).Generally, direct evidence and network meta-analysis estimates (direct plus indirect evidence) were numerically similar and consistent with confidence intervals of effect sizes overlapping.The most commonly reported adverse events across all drugs were drowsiness/fatigue, headache or migraine, gastrointestinal disturbances, dizziness/faintness and rash or skin disorders.

AUTHORS' CONCLUSIONS

Overall, the high-quality evidence provided by this review supports current guidance (e.g. NICE) that carbamazepine and lamotrigine are suitable first-line treatments for individuals with partial onset seizures and also demonstrates that levetiracetam may be a suitable alternative. High-quality evidence from this review also supports the use of sodium valproate as the first-line treatment for individuals with generalised tonic-clonic seizures (with or without other generalised seizure types) and also demonstrates that lamotrigine and levetiracetam would be suitable alternatives to either of these first-line treatments, particularly for those of childbearing potential, for whom sodium valproate may not be an appropriate treatment option due to teratogenicity.

Effect of zonisamide on refractory epilepsy during pregnancy in lamotrigine resistant kindled rats

Drug-resistant epilepsy with uncontrolled severe seizures despite state-of-the-art medical treatment continues to be a major clinical problem. Pregnancy is a state where drug pharmacokinetic changes are more pronounced and more rapid than any other period of life. The current study investigated the effect of zonisamide (ZNS) on refractory epilepsy during pregnancy in lamotrigine-resistant kindled rats. Fifty-six lamotrigine (LTG)-resistant kindled Wistar rats were divided into five experimental (four pregnant and one non-pregnant) and 2 positive controls (pregnant and non-pregnant) groups and eight intact Wistar rats were put in the negative pregnant control group. Experimental groups received daily ZNS 50mg/kg by oral gavage and 30min later, pentylenetetrazol (PTZ) (30mg/kg) was injected intraperitoneal (i.p) on Gestational Days 10-15 (in rats with or without ZNS or methanol and ethyl acetate as a ZNS solvent challenge in days -5 to 0) or Days 15-20 and for six days in the non-pregnant group. The positive control groups received the ZNS solvent for the same number of days, but the negative pregnant control group did not receive any treatment. Epilepsy was significantly controlled by ZNS in the experimental groups compared to the positive control groups. It was concluded that ZNS can control refractory epilepsy during pregnancy and increase pregnancy survival in refractory epileptic rats.

Antiepileptic drug monotherapy for epilepsy: a network meta-analysis of individual participant data

BACKGROUND

Epilepsy is a common neurological condition with a worldwide prevalence of around 1%. Approximately 60% to 70% of people with epilepsy will achieve a longer-term remission from seizures, and most achieve that remission shortly after starting antiepileptic drug treatment. Most people with epilepsy are treated with a single antiepileptic drug (monotherapy) and current guidelines from the National Institute for Health and Care Excellence (NICE) in the United Kingdom for adults and children recommend carbamazepine or lamotrigine as first-line treatment for partial onset seizures and sodium valproate for generalised onset seizures; however a range of other antiepileptic drug (AED) treatments are available, and evidence is needed regarding their comparative effectiveness in order to inform treatment choices.

OBJECTIVES

To compare the time to withdrawal of allocated treatment, remission and first seizure of 10 AEDs (carbamazepine, phenytoin, sodium valproate, phenobarbitone, oxcarbazepine, lamotrigine, gabapentin, topiramate, levetiracetam, zonisamide) currently used as monotherapy in children and adults with partial onset seizures (simple partial, complex partial or secondary generalised) or generalised tonic-clonic seizures with or without other generalised seizure types (absence, myoclonus).

SEARCH METHODS

We searched the following databases: Cochrane Epilepsy's Specialised Register, CENTRAL, MEDLINE and SCOPUS, and two clinical trials registers. We handsearched relevant journals and contacted pharmaceutical companies, original trial investigators, and experts in the field. The date of the most recent search was 27 July 2016.

SELECTION CRITERIA

We included randomised controlled trials of a monotherapy design in adults or children with partial onset seizures or generalised onset tonic-clonic seizures (with or without other generalised seizure types).

DATA COLLECTION AND ANALYSIS

This was an individual participant data (IPD) review and network meta-analysis. Our primary outcome was 'time to withdrawal of allocated treatment', and our secondary outcomes were 'time to achieve 12-month remission', 'time to achieve six-month remission', 'time to first seizure post-randomisation', and 'occurrence of adverse events'. We presented all time-to-event outcomes as Cox proportional hazard ratios (HRs) with 95% confidence intervals (CIs). We performed pairwise meta-analysis of head-to-head comparisons between drugs within trials to obtain 'direct' treatment effect estimates and we performed frequentist network meta-analysis to combine direct evidence with indirect evidence across the treatment network of 10 drugs. We investigated inconsistency between direct estimates and network meta-analysis via node splitting. Due to variability in methods and detail of reporting adverse events, we have not performed an analysis. We have provided a narrative summary of the most commonly reported adverse events.

MAIN RESULTS

IPD was provided for at least one outcome of this review for 12,391 out of a total of 17,961 eligible participants (69% of total data) from 36 out of the 77 eligible trials (47% of total trials). We could not include IPD from the remaining 41 trials in analysis for a variety of reasons, such as being unable to contact an author or sponsor to request data, data being lost or no longer available, cost and resources required to prepare data being prohibitive, or local authority or country-specific restrictions.We were able to calculate direct treatment effect estimates for between half and two thirds of comparisons across the outcomes of the review, however for many of the comparisons, data were contributed by only a single trial or by a small number of participants, so confidence intervals of estimates were wide.Network meta-analysis showed that for the primary outcome 'Time to withdrawal of allocated treatment,' for individuals with partial seizures; levetiracetam performed (statistically) significantly better than both current first-line treatments carbamazepine and lamotrigine; lamotrigine performed better than all other treatments (aside from levetiracetam), and carbamazepine performed significantly better than gabapentin and phenobarbitone (high-quality evidence). For individuals with generalised onset seizures, first-line treatment sodium valproate performed significantly better than carbamazepine, topiramate and phenobarbitone (moderate- to high-quality evidence). Furthermore, for both partial and generalised onset seizures, the earliest licenced treatment, phenobarbitone seems to perform worse than all other treatments (moderate- to high-quality evidence).Network meta-analysis also showed that for secondary outcomes 'Time to 12-month remission of seizures' and 'Time to six-month remission of seizures,' few notable differences were shown for either partial or generalised seizure types (moderate- to high-quality evidence). For secondary outcome 'Time to first seizure,' for individuals with partial seizures; phenobarbitone performed significantly better than both current first-line treatments carbamazepine and lamotrigine; carbamazepine performed significantly better than sodium valproate, gabapentin and lamotrigine. Phenytoin also performed significantly better than lamotrigine (high-quality evidence). In general, the earliest licenced treatments (phenytoin and phenobarbitone) performed better than the other treatments for both seizure types (moderate- to high-quality evidence).Generally, direct evidence and network meta-analysis estimates (direct plus indirect evidence) were numerically similar and consistent with confidence intervals of effect sizes overlapping.The most commonly reported adverse events across all drugs were drowsiness/fatigue, headache or migraine, gastrointestinal disturbances, dizziness/faintness and rash or skin disorders.

AUTHORS' CONCLUSIONS

Overall, the high-quality evidence provided by this review supports current guidance (e.g. NICE) that carbamazepine and lamotrigine are suitable first-line treatments for individuals with partial onset seizures and also demonstrates that levetiracetam may be a suitable alternative. High-quality evidence from this review also supports the use of sodium valproate as the first-line treatment for individuals with generalised tonic-clonic seizures (with or without other generalised seizure types) and also demonstrates that lamotrigine and levetiracetam would be suitable alternatives to either of these first-line treatments, particularly for those of childbearing potential, for whom sodium valproate may not be an appropriate treatment option due to teratogenicity.

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.

Phenytoin versus valproate monotherapy for partial onset seizures and generalised onset tonic-clonic seizures: an individual participant data review

BACKGROUND

Worldwide, phenytoin and valproate are commonly used antiepileptic drugs. It is generally believed that phenytoin is more effective for partial onset seizures, and that valproate is more effective for generalised onset tonic-clonic seizures (with or without other generalised seizure types). This review is one in a series of Cochrane reviews investigating pair-wise monotherapy comparisons. This is the latest updated version of the review first published in 2001 and updated in 2013.

OBJECTIVES

To review the time to withdrawal, remission and first seizure of phenytoin compared to valproate when used as monotherapy in people with partial onset seizures or generalised tonic-clonic seizures (with or without other generalised seizure types).

SEARCH METHODS

We searched the Cochrane Epilepsy Group's Specialised Register (19 May 2015), the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library; 2015, Issue 4), MEDLINE (1946 to 19 May 2015), SCOPUS (19 February 2013), ClinicalTrials.gov (19 May 2015), and WHO International Clinical Trials Registry Platform ICTRP (19 May 2015). We handsearched relevant journals, contacted pharmaceutical companies, original trial investigators and experts in the field.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in children or adults with partial onset seizures or generalised onset tonic-clonic seizures with a comparison of valproate monotherapy versus phenytoin monotherapy.

DATA COLLECTION AND ANALYSIS

This was an individual participant data (IPD) review. Outcomes were time to: (a) withdrawal of allocated treatment (retention time); (b) achieve 12-month remission (seizure-free period); (c) achieve six-month remission (seizure-free period); and (d) first seizure (post-randomisation). We used Cox proportional hazards regression models to obtain study-specific estimates of hazard ratios (HRs) with 95% confidence intervals (CIs), and the generic inverse variance method to obtain the overall pooled HR and 95% CI.

MAIN RESULTS

IPD were available for 669 individuals out of 1119 eligible individuals from five out of 11 trials, 60% of the potential data. Results apply to partial onset seizures (simple, complex and secondary generalised tonic-clonic seizures), and generalised tonic-clonic seizures, but not other generalised seizure types (absence or myoclonus seizure types). For remission outcomes: HR > 1 indicates an advantage for phenytoin; and for first seizure and withdrawal outcomes: HR > 1 indicates an advantage for valproate.The main overall results (pooled HR adjusted for seizure type) were time to: (a) withdrawal of allocated treatment 1.09 (95% CI 0.76 to 1.55); (b) achieve 12-month remission 0.98 (95% CI 0.78 to 1.23); (c) achieve six-month remission 0.95 (95% CI 0.78 to 1.15); and (d) first seizure 0.93 (95% CI 0.75 to 1.14). The results suggest no overall difference between the drugs for these outcomes. We did not find any statistical interaction between treatment and seizure type (partial versus generalised).

AUTHORS' CONCLUSIONS

We have not found evidence that a significant difference exists between phenytoin and valproate for the outcomes examined in this review. However misclassification of seizure type may have confounded the results of this review. Results do not apply to absence or myoclonus seizure types. No outright evidence was found to support or refute current treatment policies.

Valproic acid after five decades of use in epilepsy: time to reconsider the indications of a time-honoured drug

Since the serendipitous discovery of its anticonvulsant properties more than 50 years ago, valproic acid has become established as an effective broad-spectrum antiepileptic drug that is particularly useful for the management of generalised epilepsies, for which treatment alternatives are few. However, during the past few years increasing evidence has accumulated that intake of valproic acid during pregnancy is associated with a significant risk of dose-dependent teratogenic effects and impaired postnatal cognitive development in children. Because of these risks, valproic acid should not be used as a first-line drug in women of childbearing potential whenever equally or more effective alternative drugs are available-as in the case of focal epilepsy. In some generalised epilepsy syndromes, such as juvenile myoclonic epilepsy, valproic acid has better documented efficacy than alternative drugs and drug selection should be a shared decision between the clinician and the informed patient based on careful risk-benefit assessment.

Birth defects and epilepsy medication

Epilepsy is one of the most common neurological problems in pregnancy. Approximately one in 200 pregnancies is to a woman with epilepsy taking antiepileptic drugs. For the majority of women, pregnancy proceeds without any apparent difficulties but there is growing evidence of an increased risk of major malformations and later cognitive problems in children exposed to antiepileptic drugs in utero. This review summarizes the available evidence for these risks and examines the implications of these in the counseling and treatment of women with epilepsy.

Use of antiepileptic drugs in pregnancy

Babies born to mothers exposed to antiepileptic drugs (AEDs) are at increased risk for major congenital malformations, cognitive impairment and fetal death. For the millions of women with epilepsy, maintaining the safest drug that will successfully prevent seizures during pregnancy remains a primary consideration. The recent development of collaborative international registries to examine the differential and dose-dependent effects of the expanding number of old and new AEDs, have shed light upon potential differences during pregnancy. Valproic acid appears to be associated with the highest risk of overall, as well as AED-specific, birth defects, becoming more evident as doses exceed 1000 mg/day. Lamotrigine may be less teratogenic to humans than other AEDs, although orofacial clefts have recently been reported. The effects of polytherapy appear to carry greater risks compared with monotherapy. Limited data exist for many of the newer AEDs. Furthermore, AED effects may persist during postnatal development. Although no class 1 outcome data are available, prepregnancy counseling to optimize patient-specific treatment is recommended for women of childbearing potential with epilepsy.

Phenytoin versus valproate monotherapy for partial onset seizures and generalised onset tonic-clonic seizures

BACKGROUND

This is an updated version of the previously published Cochrane review (Issue 4, 2009)Worldwide, phenytoin and valproate are commonly used antiepileptic drugs. It is generally believed that phenytoin is more effective for partial onset seizures, and that valproate is more effective for generalised onset tonic-clonic seizures with or without other generalised seizure types.

OBJECTIVES

To review the best evidence comparing phenytoin and valproate when used as monotherapy in individuals with partial onset seizures or generalised onset tonic-clonic seizures with or without other generalised seizure types.

SEARCH METHODS

We searched the Cochrane Epilepsy Group's Specialised Register (19 February 2013), the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 1, The Cochrane Library, January 2013), MEDLINE (1946 to 18 February 2013), SCOPUS (19 February 2013), ClinicalTrials.gov (19 February 2013), and WHO International Clinical Trials Registry Platform ICTRP (19 February 2013). We handsearched relevant journals, contacted pharmaceutical companies, original trial investigators and experts in the field.

SELECTION CRITERIA

Randomised controlled trials in children or adults with partial onset seizures or generalised onset tonic-clonic seizures with a comparison of valproate monotherapy versus phenytoin monotherapy.

DATA COLLECTION AND ANALYSIS

This was an individual patient data review. Outcomes were time to (a) treatment withdrawal (b) 12-month remission (c) six-month remission and (d) first seizure post randomisation. Cox proportional hazards regression models were used to obtain study-specific estimates of hazard ratios (HRs) with 95% confidence intervals (CIs) with the generic inverse variance method used to obtain the overall pooled HR and 95% CI.

MAIN RESULTS

Individual patient data were available for 669 individuals out of 1119 eligible individuals from five out of 11 trials, 60% of the potential data. Results apply to generalised tonic-clonic seizures, but not absence or myoclonus seizure types. For remission outcomes, HR > 1 indicates an advantage for phenytoin and for first seizure and withdrawal outcomes HR > 1 indicates an advantage for valproateThe main overall results (pooled HR adjusted for seizure type, 95% CI) were time to (a) withdrawal of allocated treatment 1.09 (0.76 to 1.55); (b) 12-month remission 0.98 (0.78 to 1.23); (c) six-month remission 0.95 (0.78 to 1.15) and (d) first seizure 0.93 (0.75 to 1.14). The results suggest no overall difference between the drugs for these outcomes. No statistical interaction between treatment and seizure type (partial versus generalised) was found, but misclassification of seizure type may have confounded the results of this review.

AUTHORS' CONCLUSIONS

We have not found evidence that a significant difference exists between phenytoin and valproate for the outcomes examined in this review. However misclassification of seizure type may have confounded the results of this review. Results do not apply to absence or myoclonus seizure types. No outright evidence was found to support or refute current treatment policies.

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.

Prenatal-onset neurodevelopmental disorders secondary to toxins, nutritional deficiencies, and maternal illness

Neurodevelopmental disorders result from an inordinate number of genetic and environmental causes during the embryological and fetal periods of life. In the clinical setting, deciphering precise etiological diagnoses is often difficult. Newer screening technologies allow a gradual shift from traditional nature-versus-nurture debates toward the focused analysis of gene-by-environment interactions (G X E). Further understanding of developmental adaptation and plasticity requires consideration of epigenetic processes such as maternal nutritional status, environmental toxins, maternal illnesses, as well as genetic determinants, alone or in combination. Appreciation of specific G X E mechanisms of neurodevelopmental pathogenesis should lead to better risk-modifying or preventive strategies. We provide a brief overview of clinical and experimental observations that link prenatal-onset toxic exposures, metabolic disturbances, and maternal illnesses to certain neurodevelopmental disorders.

Teratogenesis in repeated pregnancies in antiepileptic drug-treated women

PURPOSE

Considerable information is now available concerning the risk of teratogenesis in the individual pregnancy exposed to antiepileptic drugs (AEDs). However, there is comparatively little information available concerning the risk in the subsequent pregnancies of women who continue to take the AED associated with a fetal malformation in a previous pregnancy. This article addresses this matter.

METHODS

Analysis of data concerning fetal abnormalities in 1,243 women who had 2,637 pregnancies between mid-1999 and 2010 recorded in the Australian Register of Antiepileptic Drugs in Pregnancy. Of the 2,637 pregnancies, 1,114 had been completed before initial enrolment in the Register.

KEY FINDINGS

Women taking any AED who had given birth to a malformed baby in their first enrolled pregnancy and who continue taking the same drug were at increased risk of having a malformed offspring in their next pregnancy (35.7% vs. 3.1%; odds ratio [OR] 17.6; 95% confidence interval [95% CI] 4.5-68.7). Among these women, those taking valproate (VPA) were more likely to have malformed fetuses in their next pregnancies than those who had taken VPA without fetal abnormalities (57.2% vs. 7.0%, OR 17.8; 95% CI 2.7, 119.1). There were similar although not statistically significant trends in those who had taken AEDs other than VPA. Similar, although again not statistically significant, trends were found, when considering the pairings of the most recent preenrollment pregnancy and the following one. If a woman had two or more pregnancies that resulted in AED-associated fetal malformation, the types of malformation were often different.

SIGNIFICANCE

Women whose last pregnancy resulted in a fetal malformation have a substantially increased risk of having further malformed fetuses if they become pregnant again while taking the same AED, particularly VPA. This suggests that maternal factors, perhaps genomic, predispose to at least VPA-associated malformations. This knowledge, together with information about the outcome of any previous pregnancy, should help in advising women with AED-treated epilepsy who plan further pregnancies.

Antiepileptic drugs and pregnancy outcomes

The treatment of epilepsy in women of reproductive age remains a clinical challenge. While most women with epilepsy (WWE) require anticonvulsant drugs for adequate control of their seizures, the teratogenicity associated with some antiepileptic drugs (AEDs) is a risk that needs to be carefully addressed. Antiepileptic medications are also used to treat an ever broadening range of medical conditions such as bipolar disorder, migraine prophylaxis, cancer, and neuropathic pain. Despite the fact that the majority of pregnancies of WWE who are receiving pharmacological treatment are normal, studies have demonstrated that the risk of having a pregnancy complicated by a major congenital malformation is doubled when comparing the risk of untreated pregnancies. Furthermore, when AEDs are used in polytherapy regimens, the risk is tripled, especially when valproic acid (VPA) is included. However, it should be noted that the risks are specific for each anticonvulsant drug. Some investigations have suggested that the risk of teratogenicity is increased in a dose-dependent manner. More recent studies have reported that in utero exposure to AEDs can have detrimental effects on the cognitive functions and language skills in later stages of life. In fact, the FDA just issued a safety announcement on the impact of VPA on cognition (Safety Announcement 6-30-2011). The purpose of this document is to review the most commonly used compounds in the treatment of WWE, and to provide information on the latest experimental and human epidemiological studies of the effects of AEDs in the exposed embryos.

Patient knowledge about issues related to pregnancy in epilepsy: a cross-sectional study

In 2009, new guidelines were established by the American Academy of Neurology regarding pregnancy in women with epilepsy. A questionnaire was developed to assess patient knowledge of current guidelines related to epilepsy and pregnancy. Patients were recruited from a single outpatient clinic in a large Canadian tertiary care center. Patients were eligible to participate if they were female, of reproductive age, had active epilepsy for at least 6 months and were not cognitively impaired. One hundred women completed the survey (response rate 87%) with a median score of 40%. A significant association was found between total score and years of education (p<0.001). Significant associations were not found between total score and epilepsy duration (p=0.37), previously being pregnant (p=0.22), and polytherapy (p=0.31). Patient knowledge of the impact of epilepsy on pregnancy is low. More knowledge translation efforts are required to increase knowledge of issues related to pregnancy for women with epilepsy.

Do lamotrigine and levetiracetam solve the problem of using sodium valproate in women with epilepsy?

Women with epilepsy, especially those of child-bearing age, are faced with difficult choices when it comes to choosing the most suitable antiepileptic drug (AED). This is particularly so for those with idiopathic generalized epilepsies, or those for whom seizure syndrome is not immediately apparent, where sodium valproate is still considered the drug of choice. While with treatment most might expect to become seizure free, without any adverse effects, other considerations for women mean that valproate is usually initially avoided, with other AEDs such as lamotrigine or levetiracetam being chosen in preference. Based on current information, this article attempts to provide an overview on whether or not the availability of these and other broad-spectrum AEDs have solved the difficulties of using valproate in women of child-bearing age.

The prescribing of antiepileptic drugs for pregnant Australian women

BACKGROUND

It is not clear how widely it is appreciated in Australia that certain antiepileptic drugs, particularly valproate, are teratogenic.

AIM

The aim of the study is to assess trends in the pattern of antiepileptic drug prescribing for pregnant women in Australia to determine whether drug use is optimal, particularly from the fetal viewpoint.

METHODS

Analysis of data contained in the Australian Register of Antiepileptic Drugs, assessing trends in antiepileptic drug use correlated with pregnancy outcomes.

RESULTS

Valproate was the only significant teratogen among the antiepileptic drugs in common use. There was a fetal malformation rate of 14.5% associated with its use in monotherapy, as compared with a rate of 3.15% in antiepileptic drug-unexposed pregnancies in women with epilepsy (OR = 5.23, 95% CI = 1.81, 15.09). The highest malformation rate associated with any other antiepileptic drug used in monotherapy was 5.0%, for carbamazepine. Neurologists had progressively prescribed valproate less frequently and in lower dosage than other classes of practitioner over the 10-year study period, with a parallel decrease in occurrence of fetal malformations in pregnancies referred to the Register. Other prescribers of valproate did not seem to have adopted these practices to the same extent and had not obtained similar degrees of reduction in the occurrence of fetal malformations.

CONCLUSIONS

Contemporary Australian obstetricians, even though they may not be valproate prescribers, when managing pregnancies in women taking valproate, need to be alert to the possibility that it may not be being used optimally from the fetal point of view, especially when not prescribed by neurologists.

Interpretation of controversial teratogenic findings of drugs such as phenobarbital

Objective. To check the debated association between phenobarbital treatment during pregnancy and risk for congenital abnormalities (CAs) in their children. Study Design. It is a comparison of phenobarbital treatment in the mothers of cases with CA and matched controls without CAs in the Hungarian Case-Control Surveillance System of Congenital Abnormalities. Results. Of 22,843 cases with CA, 149 (0.65%) had mothers with phenobarbital treatment, while of 38,151 control newborn infants without CA, 209 (0.55%) were born to mothers with phenobarbital treatment (100-400 mg daily) (OR with 95% CI : 1.3, 1.1-1.7). Of 16 CA groups, only hypospadias had a higher risk after phenobarbital treatment in the critical period of this CA (OR with 95% CI : 2.4, 1.1-5.4). However, if only medically recorded phenobarbital treatments were evaluated and multiple testing bias was considered, this association would disappear. Conclusions. This study stresses the importance of the exclusion of recall bias and multiple testing bias.

Antiepileptic treatment in pregnant women: morphological and behavioural effects

It is well established that children exposed to antiepileptic drugs (AEDs) in utero have an increased risk of adverse pregnancy outcomes including foetal growth retardation, major congenital malformations and impaired postnatal cognitive development. However, due to the significant maternal and foetal risks associated with uncontrolled epileptic seizures, AED treatment is generally maintained during pregnancy in the majority of women with active epilepsy. The prevalence of major malformations in children exposed to AEDs has ranged from 4 to 10%, 2-4 times higher than in the general population. More recent studies suggest a smaller increase in malformation rates. Malformation rates have consistently been higher in association with exposure to valproate than with carbamazepine and lamotrigine. Some prospective cohort studies also indicate reduced cognitive outcome in children exposed to valproate compared to carbamazepine and possibly lamotrigine. Information on pregnancy outcomes with newer generation AEDs other than lamotrigine are still insufficient.

Pregnancy with epilepsy: obstetric and neonatal outcome of a controlled study

PURPOSE

To determine the influence of epilepsy and its treatment on pregnancy and its outcome.

DESIGN

Controlled, observational study.

SETTING

National Health Service maternity hospitals in Liverpool and Manchester regions.

POPULATION

277 women with epilepsy (WWE) and 315 control women.

METHODS

WWE were recruited from antenatal clinics. Controls were matched for age and parity but not gestational age. Information was obtained by interview and from clinical records.

MAIN OUTCOME MEASURES

Obstetric complications, mode of delivery, condition of newborn.

RESULTS

Distribution of epilepsy syndromes was similar to previous surveys. Most WWE (67%) received monotherapy with carbamazepine, sodium valproate or lamotrigine. Half WWE had no seizures during pregnancy but 34% had tonic clonic seizures. Seizure-related injuries were infrequent. Pregnancies with obstetric complications were increased in women with treated epilepsy (WWTE 45%, controls 33%; p=0.01). Most had normal vaginal delivery (WWTE 63%, controls 61%; p=0.65). Low birth weight was not increased (WWTE 6.2%, controls 5.2%; p=0.69). There were more major congenital malformations (MCM) (WWTE 6.6%, controls 2.1%; p=0.02) and fetal/infant deaths (WWTE 2.2%, controls 0.3%; p=0.09). Amongst monotherapies MCM prevalence was highest with valproate (11.3%; p=0.005). Lamotrigine (5.4%; p=0.23) and carbamazepine (3.0%; p=0.65) were closer to controls (2.1%). There was no association between MCM and dose of folic acid pre-conception.

CONCLUSION

MCM were more prevalent in the babies of WWTE particularly amongst those receiving sodium valproate.

The management of epilepsy in pregnancy

While most women with epilepsy can expect a normal pregnancy outcome, epilepsy remains a significant contributor to both maternal and perinatal morbidity. Pre-pregnancy planning must address reliable contraception and optimisation of antiepileptic drug (AED) regimens to minimise teratogenic risk while maintaining seizure control. The most recent data from the AED registries regarding malformations is presented in this review, as is the limited data on the newer AEDs and studies linking neurocognitive outcomes to AED exposure. During pregnancy, important considerations include; therapeutic drug monitoring, surveillance for obstetric complications and vigilance for seizures during the intrapartum and postpartum period.

Gender-specific psychosocial impact of living with epilepsy

Although many psychosocial issues affect all people living with epilepsy, certain issues either are specific to one gender or have a different prevalence or significance between men and women with epilepsy. Most studies suggest that the incidence of epilepsy is slightly higher in males with epilepsy. Sexual dysfunction is common among men and women with epilepsy and has been related to epilepsy type and treatment. Women living with epilepsy are often prone to increased seizure frequency at certain phases of their menstrual cycles. Hormone replacement therapy in postmenopausal women may worsen seizures. Treatment during pregnancy is often a precarious balancing act between the teratogenic risks of AEDs and the maintenance of maternal seizure control. However, pregnancy registries and other prospective studies have given us invaluable information on how to optimize treatment regimens as well as information about safety of breastfeeding. These gender-specific factors should be a key consideration when counseling and treating patients with epilepsy.

Practice parameter update: management issues for women with epilepsy--focus on pregnancy (an evidence-based review): teratogenesis and perinatal outcomes: report of the Quality Standards Subcommittee and Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology and American Epilepsy Society

OBJECTIVE

To reassess the evidence for management issues related to the care of women with epilepsy (WWE) during pregnancy.

METHODS

Systematic review of relevant articles published between January 1985 and June 2007.

RESULTS

It is highly probable that intrauterine first-trimester valproate (VPA) exposure has higher risk of major congenital malformations (MCMs) compared to carbamazepine and possible compared to phenytoin or lamotrigine. Compared to untreated WWE, it is probable that VPA as part of polytherapy and possible that VPA as monotherapy contribute to the development of MCMs. It is probable that antiepileptic drug (AED) polytherapy as compared to monotherapy regimens contributes to the development of MCMs and to reduced cognitive outcomes. For monotherapy, intrauterine exposure to VPA probably reduces cognitive outcomes. Further, monotherapy exposure to phenytoin or phenobarbital possibly reduces cognitive outcomes. Neonates of WWE taking AEDs probably have an increased risk of being small for gestational age and possibly have an increased risk of a 1-minute Apgar score of <7.

RECOMMENDATIONS

If possible, avoidance of valproate (VPA) and antiepileptic drug (AED) polytherapy during the first trimester of pregnancy should be considered to decrease the risk of major congenital malformations (Level B). If possible, avoidance of VPA and AED polytherapy throughout pregnancy should be considered to prevent reduced cognitive outcomes (Level B). If possible, avoidance of phenytoin and phenobarbital during pregnancy may be considered to prevent reduced cognitive outcomes (Level C). Pregnancy risk stratification should reflect that the offspring of women with epilepsy taking AEDs are probably at increased risk for being small for gestational age (Level B) and possibly at increased risk of 1-minute Apgar scores of <7 (Level C).

Teratogenesis associated with antibipolar agents

OBJECTIVE

To review the teratogenic effects associated with the use of Food and Drug Administration-approved agents for bipolar disorder.

METHODS

A PubMed search of all English language articles published from January 1966 to December 2008 was conducted. The key search terms included all major bipolar agents, cross-referenced with: teratogenicity, teratogen, safety, pregnancy, fetus, bipolar disorder, and malformation. The search was augmented with manual reviews of relevant article reference lists as well as http://clinicaltrials.gov and http://www.fda.gov (both last accessed in April 2008). Several pregnancy registries were also reviewed to determine malformation rates as well as teratogenesis attributable to each agent. Articles selected for review were based on author consensus, adequacy of sample size, the use of standardized experimental procedures, validated assessment measures, and overall manuscript quality.

RESULTS

Valproate is associated with the highest rate of major congenital malformations (6.2%-16%). The relative risk of neural tube defects with valproate and carbamazepine is reported as approximately 1%-5% and 0.5%-1%, respectively. Preliminary evidence suggests that the relative risk for oral clefts (cleft lip or palate) is increased with lamotrigine relative to other antiepileptic drugs (AED) (ie, approximately 0.4%). The rate of major congenital malformations is higher in fetuses exposed to AED polytherapy (ie, >or=2 drugs) in comparison with AED monotherapy. Adverse neurobehavioral effects are insufficiently reported for most agents. In-utero exposure to valproate is associated with a greater risk of developmental difficulty requiring special education interventions as well as decreased verbal IQ scores. The risk of Ebstein's anomaly associated with lithium use is increased relative to the general population. The major congenital malformation rate with chlorpromazine and atypical antipsychotics is not established as being higher than a non-exposed group; the teratogenic risks associated with the olanzapine-fluoxetine combination are unknown.

CONCLUSIONS

Well-characterized risks are associated with valproate, carbamazepine, lamotrigine, and lithium. The risks associated with psychotropic drug use need to be understood in the context of significant rates of relapse and associated morbidity when discontinuing bipolar treatment during pregnancy.

Epileptic disorders in pregnancy: an overview

PURPOSE OF REVIEW

Much new information has now become available regarding outcomes of women with epilepsy (WWE) and pregnancy.

RECENT FINDINGS

Valproate is associated with a risk of major congenital malformations within a range of 6.2-10.7%, though antiepileptic drugs (AEDs) other than valproate when used as monotherapy are associated with major congenital malformation rates ranging from 2.9 to 3.6%; the rate of major congenital malformations in WWE not treated with AEDs was similar to this at 3.1%. Seizure freedom in 9-12 months before pregnancy is associated with seizure freedom during pregnancy. A decline in AED levels can be expected during pregnancy, most dramatically for lamotrigine (but with marked variability between patients) and least with carbamazepine. Neonates born to WWE taking AEDs who receive vitamin K 1 mg intramuscularly at birth are not at additional risk of hemorrhagic disease of the newborn.

SUMMARY

The use of valproate and polytherapy with any AED combinations should be avoided, if clinically appropriate, during pregnancy. Seizure freedom in 9-12 months before pregnancy should be a goal. AED levels should be maintained at or near the therapeutic level known for that individual patient, with frequent monitoring during pregnancy as appropriate for the patient and the AED.

Antiepileptic drugs during pregnancy: what is known and which AEDs seem to be safest?

Most infants born to women with epilepsy are healthy, but there are increased risks related to in utero antiepileptic drug (AED) exposure and seizures. Emerging data from pregnancy registries and other studies allow us to better balance the anatomic teratogenic and neurodevelopmental effects of AEDs against the need to maintain maternal seizure control. Several large prospective pregnancy registries demonstrate a consistent pattern of increased risk for major congenital malformations (MCMs) with valproate (VPA) use as monotherapy, compared to nonexposed populations and to other AEDs used in monotherapy. AED polytherapy likely increases risk for MCMs, but the risk is more pronounced if VPA is included. Reduced cognitive outcomes have been reported with AED polytherapy, and with use of VPA, phenobarbital (PB), and PHT as monotherapy. Dose-dependent risk has been demonstrated with VPA for MCMs and cognitive consequences. CBZ groups show normal neurodevelopment. Increased clearance of most of the AEDs occurs during pregnancy. Use of therapeutic drug monitoring during pregnancy with LTG reduces the risk for seizure worsening. The consistent findings of increased teratogenic risk for VPA should discourage use of this medication as first-line treatment in women of childbearing age.

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.