Antiepileptic drug clearances during pregnancy and clinical implications for women with epilepsy

Prediction of lacosamide concentrations to support dose optimization during pregnancy

OBJECTIVE

We aimed to quantify and predict lacosamide exposure during pregnancy by developing a pregnancy physiologically-based pharmacokinetic model, allowing the prediction of potential dose increases to support maintaining a patient's preconception lacosamide concentrations.

METHODS

Models for nonpregnant adults and pregnant female patients were constructed using physiochemical and pharmacological parameters identified from literature review. Evaluation of plasma concentration data from human males was digitized from the literature. Concentration data in nonpregnant and pregnant human females were available from the Maternal Outcomes and Neurodevelopmental Effects of Antiepileptic Drugs (MONEAD) study, a longitudinal observational study which followed 11 nonpregnant and 16 pregnant women receiving lacosamide. Evaluation was conducted qualitatively with visual overlay (>80% of observed concentrations within 90% confidence interval) and quantitatively with average fold error and absolute average fold error (0.8-1.25 ratio acceptance criteria). Simulations of intensively-sampled dosing regimens at steady-state dosing across multiple gestational ages were conducted in Simcyp to evaluate the potential changes in lacosamide pharmacokinetics during pregnancy. Additional simulations were performed to explore the effects of cytochrome polymorphisms and glomerular filtration rate variability.

RESULTS

The model adequately described the evaluation data in nonpregnant adults and pregnant adults between 10 and 40 weeks of gestation. Estimates in patients at 40- weeks of gestation indicated that lacosamide clearance increased by 48.2% compared to nonpregnant patients. Maximum lacosamide concentration (Cmax) during a simulated dosing interval also fell by 30% from preconception to 40 weeks. A simulated dose increase of 50 mg once daily at 10 weeks of gestation supported maintenance of preconception concentration for a typical patient taking the most common dosing regimen of 200 mg, twice daily (BID), preconception.

SIGNIFICANCE

Simulated changes in lacosamide concentration align with the limited data available in observational studies. Our simulations support the use of therapeutic drug monitoring and dose adjustments to maintain the efficacy of lacosamide pharmacotherapy.

Characterization of lamotrigine disposition changes during and after pregnancy in women with epilepsy

BACKGROUND

Lamotrigine clearance can change drastically in pregnant women with epilepsy (PWWE) making it difficult to assess the need for dosing adjustments. Our objective was to characterize lamotrigine pharmacokinetics in PWWE during pregnancy and postpartum along with a control group of nonpregnant women with epilepsy (NPWWE).

METHODS

The Maternal Outcomes and Neurodevelopmental Effects of Antiepileptic Drugs (MONEAD) study was a prospective, observational, 20 site, cohort study conducted in the United States (December 2012 and February 2016). Inclusion criteria included patients aged 14-45 years, gestational age <20 weeks at the time of recruitment, IQ >70 points, and receiving lamotrigine. PWWE participated throughout pregnancy and 18 months postpartum with NPWWE having matched visit intervals. Plasma drug and hormone concentrations were measured at each of the seven visits. A population mixed-effects modeling approach was used to describe lamotrigine clearance change.

RESULTS

221 (170 PWWE, 51 NPWWE) women were included. Baseline apparent clearance (clearance for NPWWE and when not pregnant for PWWE) was identical between the two groups (2.79 L/hour. with 36% between-subject variability). Two subpopulations were identified in PWWE: ~91% of PWWE had a maximum increase to 275% of baseline clearance with 50% of the maximum increase reached at 12 weeks gestational age and ~9% had no significant change in clearance during gestation. Following delivery, a first-order mono-exponential decline (1.27 weeks-1) in clearance as a function of postpartum week described a return of clearance to baseline. The use of estrogen-based medication and enzyme-inducing antiseizure medications increased nonpregnant clearance by a further 0.33-fold and 0.84-fold, respectively.

DISCUSSION

During pregnancy, 91% of PWWE experience a 275% change from nonpregnant baseline in lamotrigine clearance whereas the remaining PWWE experience little to no change. Nonpregnant baseline lamotrigine clearance was higher in both PWWE and NPWWE with the administration of oral estrogen-containing medications. Our results are of clinical importance as they indicate a subpopulation without the need for substantial dose changes during pregnancy and a source of potential difference across nonpregnant individuals.

Adverse events associated with carbamazepine: a pharmacovigilance study using the FDA Adverse Event Reporting System

INTRODUCTION

Carbamazepine (CBZ) is a commonly used antiseizures medications (ASM), but its adverse drug reactions (ADRs) can impact the successful management of epilepsy. There are currently limited systematic studies on ADRs related to CBZ, necessitating further investigation.

AREAS COVERED

Using the FDA Adverse Event Reporting System (FAERS) database , we extracted reports where CBZ was the primary suspect, conducting subgroup analyses stratified by sex and age. Four risk signal detection methods ROR, PRR, BCPNN, and EGBM were employed to systematically analyze the ADRs associated with CBZ.

EXPERT OPINION

In the epilepsy population, ADRs related to CBZ often involve examinations, hereditary disorders, and infections. Subgroup analysis showed differences in ADR signals among male, female, elderly, and young patients. Human Herpesvirus 6 Infection and Dermatitis Exfoliative were consistent CBZ-induced ADRs, unaffected by age or sex. The study also identified previously overlooked ADRs such as bone metabolism abnormalities, ocular toxicity, and ototoxicity. Many ADRs linked to CBZ remain underreported. It is crucial to enhance monitoring and information dissemination about CBZ use in epileptic patients. Adjusting medication regimens for high-risk individuals, potentially incorporating acupuncture, traditional Chinese medicine, or alternative anti-seizure medications, should be considered when necessary.

Seizure control and adverse outcomes of lamotrigine use during pregnancy: A systematic review and meta-analysis

OBJECTIVE

This review aims to summarize existing evidence on the adverse pregnancy outcomes and seizure control effects of using lamotrigine (LTG) monotherapy in pregnancy women with epilepsy (WWE) during pregnancy.

METHODS

A comprehensive search was conducted in various databases including Cochrane, Web of Science, CBM, PubMed, Embase, CNKI, and Pregnancy Registration Center databases to identify relevant studies. The search was concluded up to January 2024. Studies comparing LTG with other antiseizure medications (ASMs) for treating epilepsy in pregnant women were included, with no language or regional restrictions.

RESULTS

A total of 19 studies were included for analysis, with 16 studies reporting adverse pregnancy outcomes and 6 studies reporting seizure control outcomes. Meta-analysis showed that compared to monotherapy with carbamazepine (CBZ), sodium valproate (VPA), and levetiracetam (LEV), LTG monotherapy had a slightly weaker ability to control seizures during pregnancy, with ORs and 95 %CIs of 0.65 (0.57-0.75; CBZ), 0.50 (0.32-0.79; VPA), and 0.55 (0.36-0.84; LEV). Regarding adverse pregnancy outcomes, the occurrence rate of LTG monotherapy was significantly lower than that of CBZ, VPA, phenytoin (PHT), and phenobarbital (PHB), with ORs and 95 %CIs ranging from 0.30 (0.25-0.35; VPA) to 0.68 (0.56-0.81; CBZ).

CONCLUSION

Based on meta-analysis, LTG and LEV appear to be preferred medications for controlling seizures during pregnancy. This review provides further support for the use of LTG monotherapy in pregnant WWE, building upon existing evidence for clinical practitioners.

The impact of pregnancy-related hormonal and physiological changes on antiseizure medications: expert perspective

INTRODUCTION

Epilepsy is a disorder of recurrent, unprovoked seizures affecting approximately 15 million individuals of childbearing potential worldwide. Patients with epilepsy rely on regular daily therapy with antiseizure medications (ASMs). Furthermore, ASMs are also prescribed for other neuropsychiatric indications (e.g. bipolar disorder, pain, migraines) with over 2% of the pregnancies in the United States involving prenatal exposure to ASMs.

AREAS COVERED

ASM concentrations are affected by hormonal and physiological changes in pregnancy, including increases in renal and hepatic blood flow, decreased protein binding, and changes in enzyme activity. Clearance changes typically reverse within a few weeks after delivery. During pregnancy, many ASMs, such as lamotrigine, levetiracetam, and oxcarbazepine, should have serum concentrations monitored and doses increased to maintain the individualized target range for seizure control. ASMs metabolized via glucuronidation, primarily lamotrigine, undergo marked increases in clearance throughout pregnancy, requiring about 3-fold the pre-pregnancy daily dose by delivery. Postpartum, ASM doses are usually decreased over several weeks to prevent drug toxicity.

EXPERT OPINION

In the future, the development of a physiologically-based pharmacokinetic model for various ASMs may enable empiric dose adjustments in pregnancy without the difficulties of frequent therapeutic drug monitoring.

Monitoring levetiracetam concentration in saliva during pregnancy is stable and feasible

AIMS

This multicenter prospective cohort study (registration no. ChiCTR2000032089) aimed to investigate the relationship between saliva and plasma levetiracetam concentrations to determine whether saliva could be used for routine monitoring of levetiracetam during pregnancy.

METHODS

The slot concentrations of levetiracetam in simultaneously obtained saliva and plasma samples were measured using UPLC-MS/MS. The correlations between saliva and plasma levetiracetam concentrations and the dose-normalized concentrations were compared among pregnant women in different stages and nonpregnant control participants with epilepsy.

RESULTS

In total, 231 patients with 407 plasma and saliva sample pairs were enrolled from 39 centers. Linear relationships between salivary and plasma levetiracetam concentrations were reported in the enrolled population (r = 0.898, p < 0.001), including pregnant (r = 0.935, p < 0.001) and nonpregnant participants (r = 0.882, p < 0.001). Plasma concentrations were moderately higher than saliva concentrations, with ratios of saliva to plasma concentrations of 0.98 for nonpregnant women, 0.98, 1, and 1.12 for pregnant women during the first trimester, the second trimester, the and third trimester, respectively. The effective range of saliva levetiracetam concentration was found to be 9.98 μg/mL (lower limit) with an area under the curve (AUC) of 0.937 (95% confidence intervals, 0.915-0.959), sensitivity of 88.9%, specificity of 86.8%, and p < 0.001, to 24.05 μg/mL (upper limit) with an AUC of 0.952 (0.914-0.99), sensitivity of 100%, specificity of 92.3%, and p = 0.007.

CONCLUSION

The saliva/plasma concentration ratio of levetiracetam remains constant during pregnancy and is similar to that in non-pregnant individuals. Monitoring levetiracetam concentration in saliva during pregnancy should be widely promoted.

Safe delivery, perinatal outcomes and breastfeeding in women with epilepsy

Safe delivery and optimal peripartum and postpartum care in women with epilepsy (WWE) is a major concern which has received limited attention in recent years. A diagnosis of epilepsy per se is not an indication for a planned cesarean section or induction of labor, even though epidemiological studies indicate that cesarean delivery is more common among WWE compared to the general population. Pregnancy in WWE is associated with an increased risk of obstetrical complications and increased perinatal morbidity and mortality, and these risks may be greater among WWE taking ASMs. Wherever feasible, pregnant WWE should be directed to specialist care. Risk minimization includes, when appropriate, dose adjustment to compensate for pregnancy-related changes in the pharmacokinetics of some ASMs. With respect to postpartum management, WWE should be advised that the benefits of breastfeeding outweigh the small risk of adverse drug reactions in the infant.

Correlation of drug dose estimated from national prescription registers with mean blood level of antiseizure medication in pregnancy

PURPOSE

The purpose was to examine the correlation of antiseizure medication drug dose estimated from prescription fill records from prescription registers with blood levels during pregnancy.

METHODS

We conducted a Nation-wide study of mothers who gave birth in Denmark between 1 January 2014 and 31 December 2018 using data from Danish Prescription and Laboratory Registers. We identified mothers with blood level measurements of antiseizure medication. The main exposure was estimated antiseizure medication dosage estimated from pregnancy-filled prescriptions in the Danish Prescription Register. The main outcome was the correlation of estimated dose with mean blood level of antiseizure medication in pregnancy. For privacy reasons, the number of blood level measurement and prescription fills were rounded to nearest 10, but proportions reported as exact values.

RESULTS

Among 298 560 pregnancies, we identified pregnancies with recorded prescription fill from the prescription register for valproate (N = 90), lamotrigine (N = 1360), levetiracetam (N = 340), topiramate (N = 100), and carbamazepine (N = 60). In these pregnancies, blood level measurements were available in 50 (53%) pregnancies for valproate, 850 (62%) pregnancies for lamotrigine, 320 (93%) pregnancies for levetiracetam, 50 (68%) pregnancies for carbamazepine, and 40 (35%) pregnancies for topiramate. Pearsons's correlation coefficients for the correlation of estimated antiseizure medication dose with mean blood levels were 0.67 (p < 0.0001) for valproate, 0.63 (p < 0.0001) for lamotrigine, 0.63 (p < 0.0001) for levetiracetam, 0.76 (<0.0001) for carbamazepine and 0.89 (<0.0001) for topiramate.

CONCLUSIONS

Dose of antiseizure medication estimated from prescription fills was a good proxy for blood levels and thus for biological exposure in pregnancy, suggesting that administrative prescription fill records may be a valuable resource for estimating exposure to antiseizure medication in pregnancy.

Therapeutic drug monitoring in pregnancy: Levetiracetam

OBJECTIVE

Levetiracetam (LEV) is an antiseizure medication that is mainly excreted by the kidneys. Due to its low teratogenic risk, LEV is frequently prescribed for women with epilepsy (WWE). Physiological changes during gestation affect the pharmacokinetic characteristics of LEV. The goal of our study was to characterize the changes in LEV clearance during pregnancy and the postpartum period, to better plan an LEV dosing paradigm for pregnant women.

METHODS

This retrospective observational study incorporated a cohort of women who were followed up at the epilepsy in pregnancy clinic at Tel Aviv Sourasky Medical Center during the years 2020-2023. Individualized target concentrations of LEV and an empirical postpartum taper were used for seizure control and to reduce toxicity likelihood. Patient visits took place every 1-2 months and included a review of medication dosage, trough LEV blood levels, week of gestation and LEV dose at the time of level measurement, and seizure diaries. Total LEV concentration/dose was calculated based on LEV levels and dose as an estimation of LEV clearance.

RESULTS

A total of 263 samples were collected from 38 pregnant patients. We observed a decrease in LEV concentration/dose (C/D) as the pregnancy progressed, followed by an abrupt postpartum increase. Compared to the 3rd trimester, the most significant C/D decrease was observed at the 1st trimester (slope = .85), with no significant change in the 2nd trimester (slope = .11). A significant increase in C/D occurred postpartum (slope = 5.23). LEV dose was gradually increased by 75% during pregnancy compared to preconception. Average serum levels (μg/mL) decreased during pregnancy. During the postpartum period, serum levels increased, whereas the LEV dose was decreased by 24%, compared to the 3rd trimester.

SIGNIFICANCE

LEV serum level monitoring is essential for WWE prior to and during pregnancy as well as postpartum. Our data contribute to determining a rational treatment and dosing paradigm for LEV use during both pregnancy and the postpartum period.

Real-world safety of Levetiracetam: Mining and analysis of its adverse drug reactions based on FAERS database

INTRODUCTION

Levetiracetam is a relatively new and widely utilized anti-seizure medication; however, limited information is available regarding its adverse effects. This study aims to thoroughly investigate, evaluate, and present evidence on the safety profile of Levetiracetam, relying on data from the FDA Adverse Event Reporting System (FAERS) database to facilitate informed clinical decision-making.

METHODS

We employed various statistical measures, including Reporting Odds Ratio (ROR), Proportionate Reporting Ratio (PRR), and analysis by the Medicines and Healthcare Products Regulatory Agency (MHRA), to identify signals of adverse reactions associated with Levetiracetam. Positive signals consistent with Designated Medical Event (DME) were singled out for focused comparison and discussion.

RESULTS

The analysis of 26,182 adverse events linked to Levetiracetam as the primary suspected drug revealed 692 positive signals spanning 22 System Organ Classes (SOCs). Nervous system disorders were the most frequently reported, followed by psychiatric disorders, and general disorders and administration site conditions. 11 positive signals consistent with Preferred Terms (PTs) in DME were identified, predominantly concentrated in 6 SOCs. Among these, rhabdomyolysis, Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS) exhibited relatively large values of A, ROR, and Chi-squared. Additionally, PTs related to spontaneous abortion, drug interaction, urethral atresia, ventricular septal defect, and atrial septal defect showed significant strength.

CONCLUSIONS

The study indicates that Levetiracetam carries a potential risk of causing rhabdomyolysis, SJS, TEN, DRESS as well as spontaneous abortion. Signals related to drug interaction, urethral atresia, ventricular septal defect, and atrial septal defect warrant heightened attention in clinical use.

Behavioral Outcomes and Neurodevelopmental Disorders Among Children of Women With Epilepsy

Importance

The association of fetal exposure to antiseizure medications (ASMs) with outcomes in childhood are not well delineated.

Objective

To examine the association of fetal ASM exposure with subsequent adaptive, behavioral or emotional, and neurodevelopmental disorder outcomes at 2, 3, and 4.5 years of age.

Design, Setting, and Participants

The Maternal Outcomes and Neurodevelopmental Effects of Antiepileptic Drugs (MONEAD) study is a prospective, observational cohort study conducted at 20 epilepsy centers in the US. A total of 456 pregnant women with epilepsy or without epilepsy were enrolled from December 19, 2012, to January 13, 2016. Children of enrolled women were followed up with formal assessments at 2, 3, 4.5, and 6 years of age. Statistical analysis took place from August 2022 to May 2023.

Exposures

Exposures included mother's epilepsy status as well as mother's ASM blood concentration in the third trimester (for children of women with epilepsy). Women with epilepsy were enrolled regardless of ASM regimen.

Main Outcomes and Measures

The primary outcome was the Adaptive Behavior Assessment System, Third Edition (ABAS-3) General Adaptive Composite (GAC) score among children at 4.5 years of age. Children of women with epilepsy and children of women without epilepsy were compared, and the associations of ASM exposures with outcomes among exposed children were assessed. Secondary outcomes involved similar analyses of other related measures.

Results

Primary analysis included 302 children of women with epilepsy (143 boys [47.4%]) and 84 children of women without epilepsy (45 boys [53.6%]). Overall adaptive functioning (ABAS-3 GAC score at 4.5 years) did not significantly differ between children of women with epilepsy and children of women without epilepsy (parameter estimate [PE], 0.4 [95% CI, -2.5 to 3.4]; P = .77). However, in adjusted analyses, a significant decrease in functioning was seen with increasing third-trimester maximum ASM blood concentrations (PE, -7.8 [95% CI, -12.6 to -3.1]; P = .001). This decrease in functioning was evident for levetiracetam (PE, -18.9 [95% CI, -26.8 to -10.9]; P < .001) and lamotrigine (PE, -12.0 [95% CI, -23.7 to -0.3]; P = .04), the ASMs with sample sizes large enough for analysis. Results were similar with third-trimester maximum daily dose.

Conclusions and Relevance

This study suggests that adaptive functioning of children of women with epilepsy taking commonly used ASMs did not significantly differ from that of children of women without epilepsy, but there was an exposure-dependent association of ASMs with functioning. Thus, psychiatric or psychological screening and referral of women with epilepsy and their offspring are recommended when appropriate. Additional research is needed to confirm these findings.

Association of oxcarbazepine concentration with seizure frequency in pregnant women with epilepsy

The management of epilepsy during pregnancy presents particular challenges for neurologists worldwide. Currently, there are no clear recommendations for oxcarbazepine (OXC) specific target concentration during pregnancy. We conducted this retrospective observational cohort study on pregnant women with epilepsy (WWE) who received OXC monotherapy or polytherapy, at the epilepsy outpatient clinic of a tertiary hospital in eastern China. Sixteen pregnancies of 16 WWE were split into the seizure-free group or the non-seizure-free group, according to whether they had been seizure free for more than one year prior to conception or not. There was a significantly decrease in OXC concentration throughout pregnancy, as indicated by the concentration/dose ratio and the ratio of target concentration (RTC). The second trimester of pregnancy was the period when seizure deterioration occurred the most, particularly in the non-seizure-free group. Lower RTC_OXC was identified to be a risk factor for increasing seizure frequency in both the total group and the non-seizure-free group in both univariate and multivariate analysis, with a threshold of 0.575 for differentiating patients at high-risk and low-risk for seizure deterioration. In conclusion, this study suggested an OXC concentration threshold of 0.575 during pregnancy for assisting neurologists in OXC drug monitoring and dose adaptation.

Assisted reproductive technology outcomes and management considerations for people with epilepsy

PURPOSE OF REVIEW

Epilepsy is a common neurologic condition amongst people with reproductive capacity, and assisted reproductive technology (ART) is being increasingly utilized. A recent population-based study described favorable outcomes of ART in this population, but other work shows how fluctuating sex hormones may influence medication concentrations and seizures.

RECENT FINDINGS

This review discusses hormonal influences on epilepsy and catamenial epilepsy, considerations regarding fertility in women with epilepsy, emerging ART outcomes, and management considerations for people with epilepsy undergoing ART.

SUMMARY

Utilizing ART is an effective treatment for people with epilepsy desiring pregnancy, but closer monitoring and antiseizure medication adjustments may be needed to ensure the best outcomes. More research is needed to better guide epilepsy care during ART.

Management of epilepsy during pregnancy and lactation

Epilepsy is a group of neurological diseases characterized by susceptibility to recurrent seizures. Antiseizure medications (ASMs) are the mainstay of treatment, but many antiseizure medications with variable safety profiles have been approved for use. For women with epilepsy in their childbearing years, the safety profile is important for them and their unborn children, because treatment is often required to protect them from seizures during pregnancy and lactation. Since no large randomized controlled trials have investigated safety in this subgroup of people with epilepsy, pregnancy registries, cohort and case-control studies from population registries, and a few large prospective cohort studies have played an important role. Valproate, in monotherapy and polytherapy, has been associated with elevated risk of major congenital malformations and neurodevelopmental disorders in children born to mothers who took it. Topiramate and phenobarbital are also associated with elevated risks of congenital malformations and neurodevelopmental disorders, though the risks are lower than those of valproate. Lamotrigine and levetiracetam are relatively safe. Insufficient data exist to reach strong conclusions about the newest antiseizure medications such as eslicarbazepine, perampanel, brivaracetam, cannabidiol, and cenobamate. Besides antiseizure medications, other treatments such as vagal nerve stimulation, responsive neurostimulation, and deep brain stimulation are likely safe. In general, breastfeeding does not appear to add any additional long term risks to the child. Creative ways of optimizing registry enrollment and data collection are needed to enhance patient safety.

Anti-Seizure Monotherapy and Early Abortion Under Real-World Conditions

Background

Most pregnant epilepsy patients need to continue using anti-seizure medications (ASMs) to control epileptic seizures.

Objective

This study aimed to evaluate the risk of early abortion in pregnant epilepsy patients exposed to anti-seizure monotherapy.

Methods and Material

We prospectively followed up pregnant epilepsy patients treated with anti-seizure monotherapy in our epilepsy center between January 2010 and January 2020 under real-world conditions. Early abortion (spontaneous abortion in the first trimester of pregnancy) was the endpoint.

Results

Of 211 pregnancies exposed to monotherapy, including 40% (n = 85) to lamotrigine (LTG), 28% (n = 58) to oxcarbazepine (OXC), 15% (n = 32) to sodium valproate (VPA), 9% (n = 19) to levetiracetam, and 8% (n = 17) to carbamazepine, six ended in early abortion. The overall risk of early abortion in pregnant patients exposed to ASM monotherapy was 2.8% (n = 6) [95% confidence interval (CI) = 0.013-0.073]. The risk of early abortion was 2.4% (n = 2) (95% CI = 0.003-0.082) in women treated with LTG, 3.5% (n = 2) (95% CI = 0.004-0.115) in women treated with OXC, and 6.3% (n = 2) (95% CI = 0.008-0.208) in women treated with VPA. The relative risk of early abortion in the LTG, OXC, and VPA groups did not reach statistical significance.

Conclusions

Although the sample size of our study was small, these results indicate that the use of anti-seizure monotherapy in pregnant epilepsy patients may not increase the risk of early miscarriage. Larger prospective studies are needed for sufficient statistical analysis.

Managing Antiseizure Medications in Pregnancy: Is Earlier and More Frequent Monitoring Better?

Background and Objective

Medication management in pregnant women with epilepsy (PWWE) poses challenges, and understanding the effects of metabolic changes on antiseizure medications (ASMs) is important in planning care for PWWE. The possible teratogenic effects and risks of poorly controlled seizures have to be weighed. There are data in the literature on clinical management of ASMs including the effects of drug levels on seizures and factors that predict seizure frequency, but timing and frequency of monitoring and dose adjustment paradigms have not been well studied.

Methods

This retrospective study was approved by the Institutional Review Board at Johns Hopkins University. We retrospectively identified adult PWWE evaluated during pregnancy at the Johns Hopkins Bayview Medical Center epilepsy clinic, between January 1, 2007, and January 1, 2021. We reviewed charts for information regarding demographics, medical and epilepsy history, medications, serum drug levels, and dosing paradigms. We assessed risk factors for breakthrough seizures with a focus on frequency and timing of laboratory testing. We calculated the dose-normalized concentration (DNC) for analysis with levetiracetam and lamotrigine, assessing changes in DNC over time by half trimesters, and analyzed DNC and effects on seizures in pregnancy. We also compared preemptive vs clinically based lamotrigine dose adjustments in managing epilepsy in pregnancy.

Results

A total of 45 pregnancies in 39 patients were included in this study, 8 generalized, 28 focal epilepsy, and 3 unclassified. 31 PWWE (36 pregnancies) were on lamotrigine and/or levetiracetam, and 14 of these pregnancies experienced breakthrough seizures, 77% in the first trimester. Seizures led to the diagnosis of pregnancy in 5 patients. The DNC for levetiracetam decreased significantly compared with prepregnancy levels by the second half of the first trimester and demonstrated variable but frequently significant or near significant reduction throughout pregnancy. DNC for lamotrigine decreased significantly in the first half of the first trimester and remained significant throughout pregnancy. Age of mother at conception, week of first ASM serum level and number of levels obtained during pregnancy, and epilepsy type were not associated with breakthrough/increase in seizures. The history of drug resistance (p = 0.038) was associated with a higher odds of seizures. In those on lamotrigine, preemptive dose adjustments demonstrated similar results regarding seizure control when compared with clinical-based or laboratory-based dose management (p = 0.531).

Discussion

This study demonstrates that frequency and timing of ASM level monitoring may not affect overall seizure outcomes during pregnancy in those on lamotrigine or levetiracetam. Furthermore, one can consider preemptive dose adjustments or a laboratory-based/clinical-based approach in managing lamotrigine as both seem safe and feasible. However, in those with drug-resistant epilepsy before pregnancy, earlier and closer monitoring is warranted given the risk of seizures early during pregnancy. Larger prospective studies are needed to confirm these results.

Changes in seizure frequency and anti-seizure medication therapy during pregnancy and one year postpregnancy

Seizure control in women with epilepsy (WWE) during pregnancy is a vital concern. The aim of this study was to compare changes in seizure frequency and anti-seizure medication (ASM ) therapy in WWE in a real-world setting over three epochs (prepregnancy, pregnancy, and postpregnancy). We screened WWE who were pregnant between 1 January 2010 and 31 December 2020 from the epilepsy follow-up registry database of a tertiary hospital in China. We reviewed and collected follow-up data for the following time periods: 12 months before pregnancy (epoch 1), throughout pregnancy and the first 6 weeks postpartum (epoch 2), and from 6 weeks to 12 months postpartum (epoch 3). Seizures were classified into two categories: tonic‒clonic/focal to bilateral tonic‒clonic seizures and non-tonic‒clonic seizures. The main indicator was the seizure-free rate over the three epochs. Using epoch 1 as a reference, we also compared the percentage of women with an increased seizure frequency, as well as changes in ASM treatment, in epochs 2 and 3. Ultimately, 271 eligible pregnancies in 249 women were included. The seizure-free rates in epoch 1, epoch 2, and epoch 3 were 38.4%, 34.7%, and 43.9%, respectively (P = 0.09). The top three ASMs used in the three epochs were lamotrigine, levetiracetam, and oxcarbazepine. Using epoch 1 as a reference, the percentages of women with increased frequencies of tonic‒clonic/focal to bilateral tonic‒clonic seizures in epoch 2 and epoch 3 were 17.0% and 14.8%, respectively, while the percentages of women with an increased frequency of non-tonic‒clonic seizures in epoch 2 and epoch 3 were 31.0% and 21.8% (P = 0.02). The percentage of women whose ASM dosages were increased in epoch 2 was higher than that in epoch 3 (35.8% vs. 27.3%, P = 0.03). The seizure frequency during pregnancy may not differ significantly from that during prepregnancy and postpregnancy if WWE are treated according to the guidelines.

Black-Box Warnings of Antiseizure Medications: What is Inside the Box?

Antiseizure medications can cause serious adverse reactions and have deleterious drug interactions that often complicate the clinical management of patients. When the US Food and Drug Administration (FDA) wants to alert healthcare providers and patients about the risk of potentially serious or fatal drug reactions, the FDA requires the manufacturers of these medications to format these warnings within a "black-box" border, and prominently display this box on the first section of the package insert; such warnings are called "black-box warnings (BBWs)". The BBW is a way for the FDA to urge physicians to evaluate patients more rigorously and carefully weigh the risks and benefits, before prescribing medication that has the potential to cause serious adverse reactions, and to formulate a plan for close monitoring during therapy. The FDA BBW provides the extra layer of safety but many healthcare providers fail to comply with these warnings. Currently, there are 26 FDA-approved antiseizure medications in the US market, 38% of which have received BBWs, and most of the antiseizure medications with BBWs are older-generation drugs. Some antiseizure medications have multiple BBWs; for example, valproic acid has three BBWs including hepatotoxicity, fetal risk, and pancreatitis, carbamazepine has BBWs of serious skin and hematological reactions, and felbamate also has two BBWs including hepatic failure and aplastic anemia. The purpose of this review is to provide insight into each BBW received by antiseizure medications and discuss the FDA recommendations for evaluating the drug benefit/risk, and for monitoring parameters before the initiation of and during treatment.

Optimizing Therapeutic Drug Monitoring in Pregnant Women: A Critical Literature Review

BACKGROUND

More than 90% of pregnant women take at least one drug during pregnancy. Drug dose adjustments during pregnancy are sometimes necessary due to various pregnancy-induced physiological alterations frequently associated with lower plasma concentrations. However, the clinical relevance or benefits of therapeutic drug monitoring (TDM) in pregnant women have not been specifically studied. Clinical pharmacokinetic studies in pregnant women are incredibly challenging for many reasons. Despite this, regulatory agencies have made efforts to encourage the inclusion of this population in clinical trials to achieve more information on the pharmacotherapy of pregnant women. This review aims to provide support for TDM recommendations and dose adjustments in pregnant women.

METHODS

The search was conducted after a predetermined strategy on PubMed and Scopus databases using the MeSH term "pregnancy" alongside other terms such as "Pregnancy and dose adjustment," "Pregnancy and therapeutic drug monitoring," "Pregnancy and PBPK," "Pregnancy and pharmacokinetics," and "Pregnancy and physiological changes."

RESULTS

The main information on TDM in pregnant women is available for antiepileptics, antipsychotics, antidepressants, antibiotics, antimalarials, and oncologic and immunosuppressive drugs.

CONCLUSIONS

More data are needed to support informed benefit-risk decision making for the administration of drugs to pregnant women. TDM and/or pharmacokinetic studies could ensure that pregnant women receive an adequate dosage of an active drug. Mechanistic modeling approaches potentially could increase our knowledge about the pharmacotherapy of this special population, and they could be used to better design dosage regimens.

Population pharmacokinetics and dosing regimen optimization of levetiracetam in epilepsy during pregnancy

AIMS

The pharmacokinetics of levetiracetam (LEV) significantly changed during pregnancy. It is a great challenge to predict the adjusted doses of LEV to reach the preconception target concentrations. This study aimed to establish a population pharmacokinetic model of LEV in women with epilepsy (WWE) during pregnancy to analyse the factors of pharmacokinetic variability and to develop a model-based individualized dosing regimen.

METHODS

A total of 166 concentration-time points from 37 WWE during pregnancy treated with LEV were collected to analyse LEV pharmacokinetics with nonlinear mixed-effects modelling. The dosing regimen was optimized by Monte Carlo simulations based on the final model.

RESULTS

The LEV pharmacokinetics in pregnant WWE were best described by a 1-compartment model of first-order absorption and elimination. The population typical value of apparent clearance (CL/F) in the final model was estimated to be 3.82 L/h (95% confidence interval 3.283-4.357 L/h) with a relative standard error of 7.2%. Both total body weight (TBW) and trimester of pregnancy were significantly associated with LEV-CL/F during pregnancy; LEV-CL/F increased by 42.72% when TBW increased from 55 to 65 kg from the first trimester to the second trimester. Monte Carlo simulations showed that dosing regimens for LEV should be individualized based on the patient's TBW and trimester of pregnancy to maximize the likelihood of achieving the therapeutic range.

CONCLUSION

This first population pharmacokinetic study of LEV in WWE during pregnancy supports the use of a weight-based and pregnancy-based dosing regimen and can lay a foundation for further optimizing the individualized dosing regimens.

Pharmacokinetics of antibodies during Pregnancy: Impact of pregnancy on the pharmacokinetics of antibodies (Part 2)

In Part 1, we provided a general description of macromolecules, pharmacokinetics (PK) characteristics in non-pregnant subjects, and the physiological changes during pregnancy. Here we further elaborate on the impact of pregnancy on the PK of antibodies through illustrative case studies (immunoglobulins, infliximab, adalimumab and eculizumab). Using published data from nonclinical and clinical studies, we present measured or calculated PK parameters from pregnant subjects comparing with data from non-pregnant subjects, if available. Due to the paucity of PK data evaluating PK of antibodies during pregnancy, we also provide examples of PK studies for small molecules. Finally, we draw conclusions on the nature and direction of PK changes for both antibodies and small molecules as well as provide recommendations for areas that would benefit from further studies.

Association of Levetiracetam Concentration With Seizure Frequency in Pregnant Women With Epilepsy

BACKGROUND AND OBJECTIVES

Pharmacologic treatment of epilepsy in pregnant women is balancing between risks for the mother and fetus. Levetiracetam (LEV) is considered to be safe during pregnancy because of its low teratogenic potential and lack of drug-drug interaction with other antiseizure medications (ASMs). Recent studies have shown decline of ASM concentrations during pregnancy because of physiologically based pharmacokinetic changes. In this study, we established this decrease in LEV concentration during pregnancy. In addition, we aimed at investigating the effect of the low LEV levels during pregnancy and developing a target value for the level during pregnancy.

METHODS

Pregnant patients using levetiracetam were studied in this retrospective cohort study. Blood samples were monthly collected through venous puncture or the dried blood spot method. ASM serum concentrations were determined at least 6 months before conception and for each month of pregnancy. Seizure frequency and ASM dosages during pregnancy were obtained from patient records. Patients were divided into 2 groups: a seizure-free group and a non-seizure-free group, which contained pregnancies in which the mother had experienced an epileptic seizure more than 12 months and less than 12 months before pregnancy, respectively.

RESULTS

We found decreased concentration/dose ratios in 29 pregnancies throughout all months of pregnancy. In the non-seizure-free group, it was found that low LEV concentrations were associated with seizure increase frequency (p = 0.022). For this group, the cutoff value with the highest sum of sensitivity and specificity was 0.466.

DISCUSSION

All in all, we recommend therapeutic drug monitoring for all pregnant patients on LEV as the concentrations of LEV significantly decrease throughout most months of pregnancy. However, this decrease in LEV concentration was only significantly correlated with seizure deterioration in patients who had a seizure in the year preceding the pregnancy. Therefore, we suggest more careful monitoring of non-seizure-free patients as they are at higher risk for experiencing an increase of seizure frequency. For this group, we advise physicians to keep LEV concentration above 65% of the preconceptional concentration. For seizure-free patients, we recommend an LEV threshold value of approximately 46% of the preconceptional concentration.

Status epilepticus in pregnancy

Status epilepticus is a frequent neurological emergency associated with a case fatality of about 10-15% depending on age, cause, and other factors, and a high burden for patients, caregivers, and society. In pregnancy, it can occur in two different clinical constellations: (1) In women with a history of epilepsy and (2) as new onset status epilepticus in pregnancy (NOSEP). Both entities are relatively rare but differ in terms of etiology. Here we describe the epidemiology, etiologies, diagnosis, clinical course with the maternal and fetal outcome, and the suggested management strategies for either manifestation. This paper was presented at the 8th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures held in September 2022.

Management of Anti-Seizure Medications during Pregnancy: Advancements in The Past Decade

Management of seizures often involves continuous medication use throughout a patient's life, including when a patient is pregnant. The physiological changes during pregnancy can lead to altered drug exposure to anti-seizure medications, increasing patient response variability. In addition, subtherapeutic anti-seizure medication concentrations in the mother may increase seizure frequency, raising the risk of miscarriage and preterm labor. On the other hand, drug exposure increases can lead to differences in neurodevelopmental outcomes in the developing fetus. Established pregnancy registries provide insight into the teratogenicity potential of anti-seizure medication use. In addition, some anti-seizure medications are associated with an increased risk of major congenital malformations, and their use has declined over the last decade. Although newer anti-seizure medications are thought to have more favorable pharmacokinetics in general, they are not without risk, as they may undergo significant pharmacokinetic changes when an individual becomes pregnant. With known changes in metabolism and kidney function during pregnancy, therapeutic monitoring of drug concentrations helps to determine if and when doses should be changed to maintain similar seizure control as observed pre-pregnancy. This review concentrates on the results from research in the past decade (2010-2022) regarding risks of major congenital malformations, changes in prescribing patterns, and pharmacokinetics of the anti-seizure medications that are prescribed to pregnant patients with epilepsy.

Current safety concerns about the use of antiseizure medications in pregnancy

INTRODUCTION

Given the high prevalence of epilepsy in women of childbearing potential (15 million out of 50 million people worldwide), antiseizure medication (ASM) use in pregnancy is common. Identifying the safest and most effective ASM to use during pregnancy is often difficult, but also crucially important. The challenge is to balance two needs: maintaining seizure control while minimizing teratogenicity.

AREAS COVERED

This review looks at seizure- and treatment-related risks to mother and fetus during pregnancy, existing healthcare information programmes, strengths and pitfalls of the main pregnancy registries, known and supposed pharmacokinetic changes during gestation, the utility of therapeutic drug monitoring, and safety concerns. Articles and related content were screened on available publications after January 2000.

EXPERT OPINION

The use of newer ASMs during pregnancy is still limited, as shown by the paucity of data collected by different pregnancy registries. Choosing these medications can be challenging, partly due to unknown pharmacokinetic modifications in pregnancy, an aspect that serum drug monitoring might help to clarify. The safest treatment is chosen also taking into account the woman's needs, concerns and wishes, but adequate pre-pregnancy counseling is necessary to properly inform her about personal and fetal risks related both to seizures and to medications.

Application of Physiologically Based Pharmacokinetic Modeling to Predict Maternal Pharmacokinetics and Fetal Exposure to Oxcarbazepine

Pregnancy is associated with physiological changes that may affect drug pharmacokinetics (PKs). The aim of this study was to establish a maternal-fetal physiologically based pharmacokinetic (PBPK) model of oxcarbazepine (OXC) and its active metabolite, 10,11-dihydro-10-hydroxy-carbazepine (MHD), to (1) assess differences in pregnancy, (2) predict changes in PK target parameters of these molecules following the current dosing regimen, (3) assess predicted concentrations of these molecules in the umbilical vein at delivery, and (4) compare different methods for estimating drug placental penetration. Predictions using the pregnancy PBPK model of OXC resulted in maternal concentrations within a 2-fold error, and extrapolation of the model to early-stage pregnancies indicated that changes in median PK parameters remained above target thresholds, requiring increased frequency of monitoring. The dosing simulation results suggested dose adjustment in the last two trimesters. We generally recommend that women administer ≥ 1.5× their baseline dose of OXC during their second and third trimesters. Test methods for predicting placental transfer showed varying performance, with the in vitro method showing the highest predictive accuracy. Exposure to MHD in maternal and fetal venous blood was similar. Overall, the above-mentioned models can enhance understanding of the maternal-fetal PK behavior of drugs, ultimately informing drug-treatment decisions for pregnant women and their fetuses.

Clinical Application of Pharmacokinetics to Appraise Adherence to Levetiracetam in Portuguese Epileptic Patients

Adherence to antiseizure drug treatment determines its effectiveness and safety, and consequently affects patients’ quality of life. Herein, we assessed adherence to levetiracetam in Portuguese patients with refractory epilepsy (n = 115), with resort to a pharmacokinetic drug monitoring approach. The pharmacokinetic parameters of levetiracetam in each patient were determined in steady-state while admitted to the hospital. Then, adherence was assessed by comparing the plasma concentration of the drug observed on the first day of hospitalization with the predicted plasma concentration, considering previously determined pharmacokinetic parameters. The rate of adherence was assessed according to gender, age, diagnosis, and antiseizure drug regimen. Among 115 enrolled patients, 49 (42.6%) were identified as non-adherent, 30 (26.1%) classified as under-consumers, and 19 (16.5%) as over-consumers. A relationship between adherence, daily dose and plasma concentrations was herein reported for the first time. Adherent patients received higher daily doses of levetiracetam [2500 (2000–3000) mg] than non-adherent over-consumers [1500 (1000–2000) mg] and non-adherent under-consumers [2000 (1500–3000) mg]. Higher average steady-state plasma concentrations of levetiracetam were found in non-adherent under-consumers [27.28 (15.33–36.36) mg/L], followed by adherent patients [22.05 (16.62–29.81) mg/L] and non-adherent over-consumers [17.50 (10.69–24.37) mg/L]. This study demonstrates that adherence (or lack thereof) influences the plasma concentrations of levetiracetam in steady-state and its pharmacological effects. Moreover, it emphasizes the importance of educating patients to encourage adherence to therapy. Otherwise, the risk of developing toxic and subtherapeutic concentrations is undeniable, compromising the therapeutic effect and safety of treatment.

Sex and gender differences in epilepsy

Sex and gender differences in epilepsy are important influencing factors in epilepsy care. In epilepsy, the hormonal differences between the sexes are important as they impact specific treatment considerations for patients at various life stages particularly during early adulthood with establishment of the menstrual cycle, pregnancy, perimenopause and menopause. Choice of antiseizure medication may have direct consequences on hormonal cycles, hormonal contraception, pregnancy and fetal risk of major congenital malformation. Conversely hormones whether intrinsic or extrinsically administered may have direct impact on antiseizure medications and seizure control. This chapter explores these important influences on the management of persons with epilepsy.

Antiseizure Medication Concentrations During Pregnancy: Results From the Maternal Outcomes and Neurodevelopmental Effects of Antiepileptic Drugs (MONEAD) Study

IMPORTANCE

During pregnancy in women with epilepsy, lower blood concentrations of antiseizure medications can have adverse clinical consequences.

OBJECTIVE

To characterize pregnancy-associated concentration changes for several antiseizure medications among women with epilepsy.

DESIGN, SETTING, AND PARTICIPANTS

Enrollment in this prospective, observational cohort study, Maternal Outcomes and Neurodevelopmental Effects of Antiepileptic Drugs (MONEAD), occurred from December 19, 2012, to February 11, 2016, at 20 US sites. Enrolled cohorts included pregnant women with epilepsy and nonpregnant control participants with epilepsy. Inclusion criteria were women aged 14 to 45 years, an intelligence quotient greater than 70 points, and, for the cohort of pregnant women, a fetal gestational age younger than 20 weeks. A total of 1087 women were assessed for eligibility; 397 were excluded and 230 declined. Data were analyzed from May 1, 2014, to June 30, 2021.

EXPOSURE

Medication plasma concentrations in women taking monotherapy or in combination with noninteracting medications. The cohort of pregnant women was monitored through 9 months post partum, with similar time points for control participants.

MAIN OUTCOMES AND MEASURES

Dose-normalized concentrations were calculated as total or unbound plasma medication concentrations divided by total daily dose. Phlebotomy was performed during 4 pregnancy study visits and 3 postpartum visits for the pregnant women and 7 visits over 18 months for control participants. The primary hypothesis was to test pregnancy changes of dose-normalized concentrations from nonpregnant postpartum samples compared with those of control participants.

RESULTS

Of the 351 pregnant women and 109 control participants enrolled in MONEAD, 326 pregnant women (median [range] age, 29 [19-43] years) and 104 control participants (median [range] age, 29 [16-43] years) met eligibility criteria for this analysis. Compared with postpartum values, dose-normalized concentrations during pregnancy were decreased by up to 56.1% for lamotrigine (15.60 μg/L/mg to 6.85 μg/L/mg; P < .001), 36.8% for levetiracetam (11.33 μg/L/mg to 7.16 μg/L/mg; P < .001), 17.3% for carbamazepine (11.56 μg/L/mg to 7.97 μg/L/mg; P = .03), 32.6% for oxcarbazepine (11.55 μg/L/mg to 7.79 μg/L/mg; P < .001), 30.6% for unbound oxcarbazepine (6.15 μg/L/mg to 4.27 μg/L/mg; P < .001), 39.9% for lacosamide (26.14 μg/L/mg to 15.71 μg/L/mg; P < .001), and 29.8% for zonisamide (40.12 μg/L/mg to 28.15 μg/L/mg; P < .001). No significant changes occurred for unbound carbamazepine, carbamazepine-10,11-epoxide, and topiramate, although a decrease was observed for topiramate (29.83 μg/L/mg to 13.77 μg/L/mg; P = .18). Additionally, compared with dose-normalized concentrations from control participants, pregnancy dose-normalized median (SE) concentrations decreased significantly by week of gestational age: carbamazepine, -0.14 (0.06) μg/L/mg (P = .02); carbamazepine unbound, -0.04 (0.01) μg/L/mg (P = .01); lacosamide, -0.23 (0.07) μg/L/mg (P < .001); lamotrigine, -0.20 (0.02) μg/L/mg (P < .001); levetiracetam, -0.06 (0.03) μg/L/mg (P = .01); oxcarbazepine, -0.14 (0.04) μg/L/mg (P < .001); oxcarbazepine unbound, -0.11 (0.03) μg/L/mg (P < .001); and zonisamide, -0.53 (0.14) μg/L/mg (P < .001) except for topiramate (-0.35 [0.20] μg/L/mg per week) and carbamazepine-10,11-epoxide (0.02 [0.01] μg/L/mg).

CONCLUSIONS AND RELEVANCE

Study results suggest that therapeutic drug monitoring should begin early in pregnancy and that increasing doses of these anticonvulsants may be needed throughout the course of pregnancy.

Status epilepticus in pregnancy: a literature review and a protocol proposal

INTRODUCTION

Status epilepticus (SE) in pregnancy represents a life-threatening medical emergency for both mother and fetus. Pregnancy-related pharmacokinetic modifications and the risks for fetus associated with the use of antiseizure medications (ASMs) and anesthetic drugs complicate SE management. No standardized treatment protocol for SE in pregnancy is available to date.

AREAS COVERED

In this review, we provide an overview of the current literature on the management of SE in pregnancy and we propose a multidisciplinary-based protocol approach.

EXPERT OPINION

Literature data are scarce (mainly anecdotal case reports or small case series). Prompt treatment of SE during pregnancy is paramount and a multidisciplinary team is needed. Benzodiazepines are the drugs of choice for SE in pregnancy. Levetiracetam and phenytoin represent the most suitable second-line agents. Valproic acid should be administered only if other ASMs failed and preferably avoided in the first trimester of pregnancy. For refractory SE, anesthetic drugs are needed, with propofol and midazolam as preferred drugs. Magnesium sulfate is the first-line treatment for SE in eclampsia. Termination of pregnancy, via delivery or abortion, is recommended in case of failure of general anesthetics. Further studies are needed to identify the safest and most effective treatment protocol.

Women's Issues in Epilepsy

PURPOSE OF REVIEW

Issues pertaining to women with epilepsy have advanced with a better understanding of multidirectional influences among hormones, seizures, and antiseizure medications, as well as pregnancy-related concerns around fertility, seizure destabilization, and antiseizure medication-associated teratogenicity. This article highlights important developments in this field and reviews best practices in the management of women with epilepsy.

RECENT FINDINGS

Important external hormonal influences may impact women with epilepsy particularly in the context of gender-affirming medications, hormonal replacement therapy, and fertility therapies. Fertility for women with epilepsy is influenced by multiple variables; however, in the absence of preexisting fertility issues, epilepsy per se is not associated with significantly impaired fertility. Once women with epilepsy are pregnant, the majority have a stable course. Antiseizure medication use in pregnancy is associated with major congenital malformations 2 to 5 times that of the general population and is highest with high-dose (≥1500 mg or greater total daily) valproate. Carefully considered changes in drug choice and dose may mitigate these risks. Therapeutic drug monitoring plays an important role in pregnancy care, and under expert supervision, women with epilepsy in pregnancy have similar seizure risks as women with epilepsy who are not pregnant. As women with epilepsy age, bone health and menopause may further be impacted by seizures and antiseizure medications.

SUMMARY

The care of women with epilepsy is a multifaceted discipline that recognizes the life-long impact of sex and gender influences on epilepsy care.

Variations in Seizure Frequency During Pregnancy and Postpartum by Epilepsy Type

BACKGROUND AND OBJECTIVES

To assess whether increased seizure frequency during pregnancy and postpartum is influenced by epilepsy type, seizure location, and antiseizure medications.

METHODS

Clinical data were collected in a longitudinal prospective database of pregnant women with epilepsy at Brigham and Women's Hospital. Within each individual participant, baseline seizure frequency was calculated for the 9 months before conception, and whether seizure frequency increased during pregnancy or the postpartum period was determined. Seizure frequency was calculated for each 4-week interval during pregnancy. Generalized estimating equations for logistic regression were applied.

RESULTS

Ninety-nine patients contributing 114 pregnancies were included from 2013 to 2018. Increased seizure frequency occurred more often during pregnancies of women with focal vs generalized epilepsy (21.1% vs 5.3%, odds ratio [OR] 4.70, 95% confidence interval [CI] 1.00-22.00; p = 0.0497). Among women with focal epilepsy, increased seizure frequency occurred more often in those with frontal lobe epilepsy (OR 8.00, 95% CI 2.19-29.21; p = 0.0017). There was no difference in seizure worsening in the postpartum period between the focal and generalized (11.1% vs 9.1%; p = 0.4478) or frontal and other focal (18.8% vs 6.0%; p = 0.1478) epilepsy groups. Pregnancies on polytherapy had higher odds of seizure worsening compared to monotherapy (OR 8.36, 95% CI 2.07-33.84; p = 0.0029), regardless of the medication or epilepsy type. A lack of preconception seizure freedom was also associated with increased seizure frequency during pregnancy (OR 6.418; p = 0.0076).

DISCUSSION

Women with focal epilepsy have higher likelihood of seizure worsening during pregnancy compared to women with generalized epilepsy; frontal lobe epilepsy poses an especially elevated risk. Polytherapy and lack of preconception seizure freedom are additional predictors for an increased likelihood of seizure worsening.

Pharmacokinetic changes for newer antiepileptic drugs and seizure control during pregnancy

Objective

To investigate pharmacokinetic changes in newer antiepileptic drugs (AEDs) and assess seizure frequencies and risk factors of increased seizures during pregnancy in women with epilepsy (WWE).

Methods

A total of 56 pregnancies in 53 WWE who received newer antiepileptic drugs (AEDs) were enrolled. Data on seizure activity and types, daily dose, and AEDs blood levels were derived from routine clinical follow‐up. Changes in AEDs clearance were compared between each trimester and nonpregnant baseline. The ratio of AED levels of each trimester to their targets (nonpregnant baseline) concentrations (RTC) was compared between patients with and without an increased seizure. A binary logistic regression was used to investigate the risk factors contributing to seizure worsening during pregnancy.

Results

Increased clearances of LTG, LEV, and OXC were observed in all trimesters versus nonpregnant baseline. The peak changes in the clearance of LTG (3.42‐fold baseline clearance) (p < 0.001) and LEV (2.78‐fold) (p < 0.001) occurred in the second trimester during pregnancy, followed by oxcarbazepine (2.11‐fold) in the third trimester (p < 0.03). Plasma concentrations of LTG and LEV during pregnancy were significantly decreased compared to baseline levels, except for OXC. However, no significant differences in RTC values were observed between patients with and without seizure worsening. Some risk factors as seizures for the prior nine months could significantly affect seizure frequency during pregnancy.

Conclusion

We found substantial changes in the pharmacokinetics of multiple newer AEDs in WWE, reinforcing the need for therapeutic drug monitoring (TDM) during pregnancy. We would encourage at least one monitoring every trimester and probably more frequently for women with poorly seizure control before pregnancy, and AEDs dose adjustment should keep up with clearance changes. In addition, a well‐controlled seizure nine months before pregnancy could lower the risks of seizure during pregnancy, highlighting the importance of pre‐pregnancy counseling and seizure management before pregnancy.

Special Considerations in the Management of Women with Epilepsy in Reproductive Years

Anti-seizure medications (ASMs) fail to prevent seizure recurrence in more than 30% of patients with epilepsy. The treatment is more difficult in premenopausal women with epilepsy (WWE) because changes in plasma estrogen and progesterone concentrations during the menstrual cycle often affect seizure frequency and intensity. Interactions between enzyme-inducin ASMs and hormonal contraceptives can lead to both a loss of seizure control and failure of contraception. Significant changes in the function of the liver and kidneys during pregnancy can accelerate metabolism and elimination of ASMs, causing breakthrough seizures. In addition, the teratogenic, cognitive, and psychological effects of ASMs on potential offspring have to be considered when choosing the best ASM regimen. Therefore, aspecialized approach is necessary for the treatment of premenopausal WWE.

Pregnancy Effects on Seizure Frequency: To Seize or Not to Seize

[Box: see text]

Epilepsy and pregnancy: identifying risks

Pregnancy is a time of physical, physiological and psychological challenge. For women with epilepsy, as well as its potential for joy and fulfilment, pregnancy may bring additional risks and difficulties. Clinicians must anticipate and prevent these complications, ensuring that pregnancy, delivery and motherhood proceed without obstetric or medical complications, using available evidence to balance individual risks of undertreatment and overtreatment. Here we review epilepsy management in pregnancy, identifying some of the known effects of epilepsy and its treatment on gestation, fetal malformation, delivery, and neurocognitive and behavioural development. We outline strategies to reduce obstetric and fetal complications in women with epilepsy, while recognising the sometimes competing need to maintain or improve seizure control. We reinforce the importance of identifying those at highest risk, who may require additional measures or safeguards.

Analysis of the Clinical Effects of Sodium Valproate and Levetiracetam in the Treatment of Women with Epilepsy during Pregnancy

Objective

To explore the clinical effects of sodium valproate and levetiracetam in the treatment of women with epilepsy during pregnancy.

Methods

The clinical data of 124 women with epilepsy during pregnancy who received monotherapy with antiepileptic drugs (AEDs) in our hospital from September 2017 to January 2020 were retrospectively analyzed. According to the type of medication taken by the patients, they were recorded as the sodium valproate group (the VPA group, n = 56) and the levetiracetam group (the LEV group, n = 68 cases). The effects and the maternal and infant outcomes after treatment were compared between the two groups. The neuron-specific enolase (NSE), cognitive function-related parameters (brain-derived neurotrophic factor (BDNF) and myelin basic protein (MBP)), and related inflammatory factors (tumor necrosis factor- (TNF-) α and interleukin- (IL-) 6) levels were compared between the two groups before and after treatment.

Results

After treatment, the total clinical effective rate of the LEV group was 91.18% higher than that of the VPA group 73.21%, and the frequency and duration of seizures were lower than those of the VPA group (P < 0.05). After treatment, the probability of gestational hypertension, depression during pregnancy, low-weight infants, and neonatal deformities in the LEV group was lower than that in the VPA group (P < 0.05). After treatment, the levels of NSE, MBP, TNF-α, and IL-6 in the two groups decreased, and the levels of BDNF increased, and the LEV group changed significantly compared with the VPA group (P < 0.05).

Conclusion

Compared with sodium valproate monotherapy, levetiracetam is more effective in controlling seizures and improving maternal and infant outcomes in women with epilepsy during pregnancy and can effectively regulate their neurological and cognitive functions and reduce the serum inflammation factor level.

Pregnant women with more seizures have lower allopregnanolone concentrations

Neuroactive steroids have rapid, nongenomic effects on neuronal excitability. The effects in humans are less clear. We compared seizure control and concentrations of neuroactive steroids, known to influence neuroexcitability in animal studies, in pregnant women. Participants were prospectively followed throughout pregnancy with seizure-medication diaries and blood samples, assayed for steroid concentrations with gas chromatography-mass spectrometry. Baseline seizure frequency was calculated for the preconception year, and it was determined if seizure frequency was increased in each trimester. The Wilcoxon rank-sum test was used to compare neuroactive steroid concentrations in between the group with increased frequency to the group without, as calculated for the respective trimester, with the Holm-Bonferroni method to correct for multiple comparisons. Among eighty-three pregnancies included, twenty-eight had increased seizure frequency during at least one trimester (15, 18 and 10, respectively) compared to preconception seizure frequency. Allopregnanolone concentrations were lower in the 3rd trimester (p < 0.001), with a similar trend in the 1st (p = 0.08), for pregnancies with increased compared to those with stable seizure frequency. Other neuroactive steroid concentrations were similar. Our findings suggest that lower allopregnanolone concentrations are associated with increased seizure frequency during pregnancy. Validation of these finding in a larger cohort has potential important clinical applications.

Two-Year-Old Cognitive Outcomes in Children of Pregnant Women With Epilepsy in the Maternal Outcomes and Neurodevelopmental Effects of Antiepileptic Drugs Study

Importance

The neurodevelopmental risks of fetal exposure are uncertain for many antiseizure medications (ASMs).

Objective

To compare children at 2 years of age who were born to women with epilepsy (WWE) vs healthy women and assess the association of maximum ASM exposure in the third trimester and subsequent cognitive abilities among children of WWE.

Design, Setting, and Participants

The Maternal Outcomes and Neurodevelopmental Effects of Antiepileptic Drugs (MONEAD) study is a prospective, observational, multicenter investigation of pregnancy outcomes that enrolled women from December 19, 2012, to January 13, 2016, at 20 US epilepsy centers. Children are followed up from birth to 6 years of age, with assessment at 2 years of age for this study. Of 1123 pregnant women assessed, 456 were enrolled; 426 did not meet criteria, and 241 chose not to participate. Data were analyzed from February 20 to December 4, 2020.

Main Outcomes and Measures

Language domain score according to the Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III), which incorporates 5 domain scores (language, motor, cognitive, social-emotional, and general adaptive), and association between BSID-III language domain and ASM blood levels in the third trimester in children of WWE. Analyses were adjusted for multiple potential confounding factors, and measures of ASM exposure were assessed.

Results

The BSID-III assessments were analyzed in 292 children of WWE (median age, 2.1 [range, 1.9-2.5] years; 155 female [53.1%] and 137 male [46.9%]) and 90 children of healthy women (median age, 2.1 [range, 2.0-2.4] years; 43 female [47.8%] and 47 male [52.2%]). No differences were found between groups on the primary outcome of language domain (-0.5; 95% CI, -4.1 to 3.2). None of the other 4 BSID-III domains differed between children of WWE vs healthy women. Most WWE were taking lamotrigine and/or levetiracetam. Exposure to ASMs in children of WWE showed no association with the language domain. However, secondary analyses revealed that higher maximum observed ASM levels in the third trimester were associated with lower BSID-III scores for the motor domain (-5.6; 95% CI, -10.7 to -0.5), and higher maximum ASM doses in the third trimester were associated with lower scores in the general adaptive domain (-1.4; 95% CI, -2.8 to -0.05).

Conclusions and Relevance

Outcomes of children at 2 years of age did not differ between children of WWE taking ASMs and children of healthy women.

Trial Registration

ClinicalTrials.gov Identifier: NCT01730170.

Women's issues

Special considerations are required for women with epilepsy. These include issues such as catamenial exacerbation, concerns for contraception, teratogenesis (including both anatomical and neurodevelopmental effects), and other concerns for pregnancy complications such as increased seizures or adverse obstetric outcomes. In this manuscript, several cases are presented and discussed addressing some of the important issues in the management of women with epilepsy.

Therapeutic Drug Monitoring of Antiepileptic Drugs in Women with Epilepsy Before, During, and After Pregnancy

During pregnancy, the pharmacokinetics of an antiepileptic drug is altered because of changes in the clearance capacity and volume of distribution. These changes may have consequences for the frequency of seizures during pregnancy and fetal exposure to antiepileptic drugs. In 2009, a review was published providing guidance for the dosing and therapeutic drug monitoring of antiepileptic drugs during pregnancy. Since that review, new drugs have been licensed and new information about existing drugs has been published. With this review, we aim to provide an updated narrative overview of changes in the pharmacokinetics of antiepileptic drugs in women during pregnancy. In addition, we aim to formulate advice for dose modification and therapeutic drug monitoring of antiepileptic drugs. We searched PubMed and the available literature on the pharmacokinetic changes of antiepileptic drugs and seizure frequency during pregnancy published between January 2007 and September 2018. During pregnancy, an increase in clearance and a decrease in the concentrations of lamotrigine, levetiracetam, oxcarbazepine's active metabolite licarbazepine, topiramate, and zonisamide were observed. Carbamazepine clearance remains unchanged during pregnancy. There is inadequate or no evidence for changes in the clearance or concentrations of clobazam and its active metabolite N-desmethylclobazam, gabapentin, lacosamide, perampanel, and valproate. Postpartum elimination rates of lamotrigine, levetiracetam, and licarbazepine resumed to pre-pregnancy values within the first few weeks after pregnancy. We advise monitoring of antiepileptic drug trough concentrations twice before pregnancy. This is the reference concentration. We also advise to consider dose adjustments guided by therapeutic drug monitoring during pregnancy if the antiepileptic drug concentration decreases 15-25% from the pre-pregnancy reference concentration, in the presence of risk factors for convulsions. If the antiepileptic drug concentration changes more than 25% compared with the reference concentration, dose adjustment is advised. Monitoring of levetiracetam, licarbazepine, lamotrigine, and topiramate is recommended during and after pregnancy. Monitoring of clobazam, N-desmethylclobazam, gabapentin, lacosamide, perampanel, and zonisamide during and after pregnancy should be considered. Because of the risk of teratogenic effects, valproate should be avoided during pregnancy. If that is impossible, monitoring of both total and unbound valproate is recommended. More research is needed on the large number of unclear pregnancy-related effects on the pharmacokinetics of antiepileptic drugs.

Estrogen profile- and pharmacogenetics-based lamotrigine dosing regimen optimization: Recommendations for pregnant women with epilepsy

During pregnancy, various physiological changes occur that can alter the pharmacokinetics of antiepileptic drugs, such as lamotrigine (LTG). Anticipating the change in LTG dose required to achieve a pre-pregnancy target concentration is challenging. This study aimed to develop a refined population pharmacokinetic (PopPK) model of LTG in pregnant women with epilepsy (WWE) to identify factors explaining the variability in pharmacokinetics and to establish a model-informed individualized dosing regimen. On that basis, a coarsened model containing only clinical variables was also developed to examine its predictive performance compared to the refined model. In total, 322 concentration-time points from 51 pregnant WWE treated with LTG were employed to establish a refined PopPK model that included endogenous estrogen profiles, variants of candidate genes encoding LTG-metabolizing enzymes and -transporter proteins, and other clinical variables and a coarsened model that included only clinical variables, respectively. Data from an additional 11 patients were used for external validation of these two models. A nonlinear mixed-effect modeling approach was used for PopPK analysis of LTG. The standard goodness-of-fit method, bootstrap, normalized prediction distribution errors and external evaluation were adopted to estimate the stability and predictive performance of the candidate models. Akaike information criterion (AIC) was used to compare the goodness of fit between these two models. A lower AIC indicates a better fit of the data and the preferred model. Recommended dosing regimens for pregnant WWE were selected using Monte Carlo simulation based on the established optimal model. In the refined PopPK model, the population mean of apparent LTG clearance (CL/F) in pregnant WWE was estimated to be 2.82 L/h, with an inter-individual variability of 23.6%. PopPK analysis indicated that changes in estrogen profile during pregnancy were the predominant reason for the significant variations in LTG-CL/F. Up to the 3rd trimester, the concentration accumulation effect of E2 increased LTG-CL/F by 5.109 L/h from baseline levels. Contrary to effect of E2, E3 as the main circulating estrogen in pregnancy with a peak value of 34.41 ng/mL is 1000-fold higher than that in non-pregnancy reduced LTG-CL/F by 1.413 L/h. In addition, the UGT2B7 rs4356975 C > T and ABCB1 rs1128503 A > G variants may contribute to a better understanding of the inter-individual variability in LTG-CL/F. LTG-CL/F was 1.66-fold higher in UGT2B7 rs4356975 CT or TT genotype carriers than in CC genotype carriers. In contrast, ABCB1 rs1128503 GG genotype carriers had only 71.9% of the LTG-CL/F of AA or AG genotype carriers. In the coarsened PopPK model, the gestational age was a promising predictor of changes in LTG-CL/F. When comparing these two models, the refined PopPK model was favored over the coarsened PopPK model (AIC = -30.899 vs. -20.017). Monte Carlo simulation based on optimal PopPK model revealed that the LTG dosage administered to carriers of the UGT2B7 rs4356975 CT or TT genotype required a 33-50% increase to reach the pre-pregnancy target concentration, and carriers of the ABCB1 rs1128503 GG genotype required a 33-66% lower dose of LTG than carriers of the ABCB1 rs1128503 AA or AG genotype. Changes in estrogen profile during pregnancy was a better predictor of variations in LTG-CL/F than gestational age. The developed model based on estrogen profile and pharmacogenetics can serve as a foundation for further optimization of dosing regimens of LTG in pregnant WWE.

Umbilical Cord, Maternal Milk, and Breastfed Infant Levetiracetam Concentrations Monitoring at Delivery and during Early Postpartum Period

(1) To obtain objective information about levetiracetam transplacental passage and its transport into colostrum, mature milk, and breastfed infants, we analyzed data from women treated for epilepsy between October 2006 and January 2021; (2) in this cohort study, maternal, umbilical cord, milk, and infant serum concentrations were measured at delivery, 2-4 days postpartum (colostrum) and 7-31 days postpartum (mature milk). Paired umbilical cord serum, maternal serum, breastfed infant serum, and milk concentrations were used to assess the ratios of umbilical cord/maternal serum, milk/maternal serum, and infant/maternal serum concentrations. The influence of combined treatment with enzyme-inducing antiseizure medication carbamazepine was assessed; (3) the umbilical cord/maternal serum concentration ratio ranged between 0.75 and 1.78 (mean 1.10 ± 0.33), paired maternal and umbilical cord serum concentrations were not significantly different, and a highly significant correlation was found between both concentrations. The mean milk/maternal serum concentration ratio was 1.14 ± 0.27 (2-4 days postpartum) and 1.04 ± 0.24 (7-31 days postpartum) while the mean infant/maternal serum concentration ratio was markedly lower (0.19 ± 0.13 and 0.14 ± 0.05, respectively); (4) levetiracetam was found in the umbilical cord at a concentration similar to those in maternal serum. All of the breastfed infant serum concentrations were below the reference range used for the general epileptic population.