MODEL-BASED LAMOTRIGINE CLEARANCE CHANGES DURING PREGNANCY: CLINICAL IMPLICATION

External Validation of Population Pharmacokinetic Models of Lamotrigine in Patients with Epilepsy or Postneurosurgery

BACKGROUND

This study aimed to evaluate the predictive performance of published lamotrigine (LTG) population pharmacokinetic (PPK) models using an external data set of Chinese patients with epilepsy or postneurosurgery.

METHODS

In total, 348 concentration measurements from 94 Chinese children and 254 Chinese adults with epilepsy or postneurosurgery were used for external validation. Data on published LTG PPK models were obtained from the literature. The predictability of the models was assessed using prediction-based diagnostics (eg, F20 and F30), simulation-based diagnostics, and Bayesian forecasting.

RESULTS

The results of prediction-based diagnostics for all 10 models were unsatisfactory. The best-performing models, characterized as one-compartment models with nonlinear pharmacokinetics, incorporated weight as a key covariate and included interindividual variability for both clearance and volume of distribution. These models achieved exceptional predictive performance in simulation-based diagnostics and Bayesian forecasting, with IF30 values of 90.32%, 97.23%, and 99.61%, respectively, demonstrating superior precision and accuracy. Bayesian forecasting improved the predictive accuracy of 80% of the models, significantly enhancing model predictability.

CONCLUSIONS

The published PPK models show extensive variation in predictive performance for extrapolation among Chinese patients with epilepsy or postneurosurgery. The lack of key covariates (such as concomitant medications, genetic polymorphisms, and age stratification) and fixed parameters of volume of distribution and absorption rate constant in the PPK modeling of LTG may explain its unsatisfactory predictive performance. Bayesian forecasting significantly improves the model predictability and may help individualize LTG dosing.

Canadian Network for Mood and Anxiety Treatments 2024 Clinical Practice Guideline for the Management of Perinatal Mood, Anxiety, and Related Disorders: Guide de pratique 2024 du Canadian Network for Mood and Anxiety Treatments pour le traitement des troubles de l'humeur, des troubles anxieux et des troubles connexes périnatals

BackgroundThe Canadian Network for Mood and Anxiety Treatments (CANMAT) publishes clinical practice guidelines for mood and anxiety disorders. This CANMAT guideline aims to provide comprehensive clinical guidance for the pregnancy and postpartum (perinatal) management of mood, anxiety and related disorders.MethodsCANMAT convened a core editorial group of interdisciplinary academic clinicians and persons with lived experience (PWLE), and 3 advisory panels of PWLE and perinatal health and perinatal mental health clinicians. We searched for systematic reviews of prevention and treatment interventions for perinatal depressive, bipolar, anxiety, obsessive-compulsive and post-traumatic stress disorders (January 2013-October 2023). We prioritized evidence from reviews of randomized controlled trials (RCTs), except for the perinatal safety of medications where reviews of large high-quality observational studies were prioritized due to the absence of RCT data. Targeted searches for individual studies were conducted when systematic reviews were limited or absent. Recommendations were organized by lines of treatment based on CANMAT-defined levels of evidence quality, supplemented by editorial group consensus to balance efficacy, safety, tolerability and feasibility considerations.ResultsThe guideline covers 10 clinical sections in a question-and-answer format that maps onto the patient care journey: case identification; organization and delivery of care; non-pharmacological (lifestyle, psychosocial, psychological), pharmacological, neuromodulation and complementary and alternative medicine interventions; high-risk clinical situations; and mental health of the father or co-parent. Equity, diversity and inclusion considerations are provided.ConclusionsThis guideline's detailed evidence-based recommendations provide clinicians with key information to promote the delivery of effective and safe perinatal mental healthcare. It is hoped that the guideline will serve as a valuable tool for clinicians in Canada and around the world to help optimize clinical outcomes in the area of perinatal mental health.

Prolonged Elimination of Lamotrigine After Suicidal Overdose: A Case Report

Lamotrigine (LTG) is an antiepileptic drug that stabilizes neuronal membranes by inhibiting excitatory neurotransmitter release, thereby reducing neuronal excitation. Various factors can contribute to its metabolic dysfunction. A 22-year-old female with bipolar disorder presented after intentionally ingesting 216 tablets, including LTG (4,100 mg), prescribed antipsychotics, over-the-counter cold medicine containing acetaminophen (27 g), and alcohol. She arrived at the hospital approximately one-hour post-ingestion in a confused state, with mild transaminase elevation but no significant electrocardiographic abnormalities. Initial management included activated charcoal, N-acetylcysteine therapy, and intravenous fluids. Despite these interventions, she deteriorated to a comatose state by hospital day two, accompanied by a mild skin rash later diagnosed as urticaria. Her hepatic function and consciousness gradually improved, with transaminase normalization and full neurological recovery by day six. She was discharged on day seven without residual deficits. Serial LTG serum measurements at 13, 55, and 79 hours post-ingestion (16.10 mg/L, 12.39 mg/L, and 6.84 mg/L, respectively) revealed a non-linear elimination pattern, with an estimated half-life of ~100 hours between the first two measurements. However, by the third measurement, elimination aligned with previously reported pharmacokinetics. The patient's young age, normal BMI, absence of hepatic disease, and minimal interaction potential with co-ingested antipsychotics did not explain the delayed LTG clearance. We hypothesize that hepatic metabolic pathway saturation led to this non-linear pharmacokinetic behavior. The resolution of delayed elimination corresponded with hepatic enzyme normalization. In drug overdose cases, prolonged consciousness disturbance may indicate an extended drug half-life due to metabolic dysfunction. If recovery exceeds expectations, further evaluation is warranted to identify and address potential causes.

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.

PBPK Modeling of Lamotrigine and Efavirenz during Pregnancy: Implications for Personalized Dosing and Drug-Drug Interaction Management

This study aimed to model the pharmacokinetics of lamotrigine (LTG) and efavirenz (EFV) in pregnant women using physiologically based pharmacokinetic (PBPK) and pregnancy-specific PBPK (p-PBPK) models. For lamotrigine, the adult PBPK model demonstrated accurate predictions for pharmacokinetic parameters. Predictions for the area under the curve (AUC) and peak plasma concentration (Cmax) generally agreed well with observed values. During pregnancy, the PBPK model accurately predicted AUC and Cmax with a prediction error (%PE) of less than 25%. The evaluation of the EFV PBPK model revealed mixed results. While the model accurately predicted certain parameters for non-pregnant adults, significant discrepancies were observed in predictions for higher doses (600 vs. 400 mg) and pregnant individuals. The model's performance during pregnancy was poor, indicating the need for further refinement to account for genetic polymorphism. Gender differences also influenced EFV pharmacokinetics, with lower exposure levels in females compared to males. These findings highlight the complexity of modeling EFV, in general, but specifically in pregnant populations, and the importance of validating such models for accurate clinical application. The study highlights the importance of tailoring dosing regimens for pregnant individuals to ensure both safety and efficacy, particularly when using combination therapies with UGT substrate drugs. Although drug-drug interactions between LTG and EFV appear minimal, further research is needed to improve predictive models and enhance their accuracy.

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.

Advances in Psychotropic Treatment for Pregnant Women: Efficacy, Adverse Outcomes, and Therapeutic Monitoring

Advancements in psychotropic therapy for pregnant women are pivotal for addressing maternal mental health during the perinatal period. Screening for mood and anxiety symptoms during pregnancy is recommended to enable early intervention. Psychotropic medications, including antidepressants, benzodiazepines, antipsychotics, and mood stabilizers, are commonly used, but challenges remain regarding their safety and efficacy during pregnancy. Pregnancy induces significant changes in pharmacokinetics, necessitating personalized dosing strategies and careful monitoring. Real-time monitoring technologies, such as smartphone-integrated platforms and home-based monitoring, enhance accessibility and accuracy. Prospective studies and collaboration among healthcare providers are essential for evidence-based guidelines and optimal treatment strategies. Reducing stigma around mental health during pregnancy is crucial to ensure women seek help and discuss treatment options, promoting understanding and acceptance within the community.

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.

Empiric dosing strategies to predict lamotrigine concentrations during pregnancy

INTRODUCTION

Maintaining seizure control with lamotrigine is complicated by altered pharmacokinetics and existence of subpopulations in whom clearance increases or remains constant during pregnancy.

OBJECTIVE

Our objective was to characterize the potential for particular dosing scenarios to lead to increased seizure risk or toxicity.

METHODS

Lamotrigine pharmacokinetic parameters obtained from our previous study were applied to a one-compartment model structure with subpopulations (75:25%) exhibiting different clearance changes. A single-patient simulation was conducted with typical pharmacokinetic parameter values from each subpopulation. Population-level simulations (N = 48,000) included six dosing scenarios and considered four preconception doses using the R package mrgsolve (Metrum Research Group). Thresholds for efficacy and toxicity were selected as drug concentration that are 65% lower than preconception concentrations and doubling of preconception concentrations, respectively.

RESULTS

Individual simulation results demonstrated that without dose increases, concentrations fell below 0.65 at 6-8 weeks in the high clearance change (HC) subpopulation, depending on preconception clearance. While no simulated dosing regimen allowed all women in both subpopulations to maintain preconception concentrations, some regimens provided a more balanced risk profile than others. Predicted concentrations suggested potential increased seizure risk for 7%-100% of women in the HC group depending on preconception dose and subpopulation. Additionally, in 63% of dosing scenarios for women with low clearance change (LC), there was an increased risk of toxicity (34%-100% of women).

SIGNIFICANCE

A substantial percentage of simulated individuals had concentrations low enough to potentially increase seizure risk or high enough to create toxicity. Early clearance changes indicate possible subpopulation categorization if therapeutic drug monitoring is conducted in the first trimester. An arbitrary "one-size-fits-all" philosophy may not work well for lamotrigine dosing adjustments during pregnancy and reinforces the need for therapeutic drug monitoring until a patient is determined to be in the LC or HC group.

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.

Design Considerations for Pharmacokinetic Studies During Pregnancy

Most of the interventions performed by obstetric providers involve the administration of drugs. Pregnant patients are pharmacologically and physiologically different from nonpregnant young adults. Therefore, dosages that are effective and safe for the general public may be inadequate or unsafe for the pregnant patient and her fetus. Establishing dosing regimens appropriate for pregnancy requires evidence generated from pharmacokinetic studies performed in pregnant people. However, performing these studies during pregnancy often requires special design considerations, evaluations of both maternal and fetal exposures, and recognition that pregnancy is a dynamic process that changes as gestational age advances. In this article, we address design challenges unique to pregnancy and discuss options for investigators, including timing of drug sampling during pregnancy, appropriate selection of control groups, pros and cons of dedicated and nested pharmacokinetic studies, single-dose and multiple-dose analyses, dose selection strategies, and the importance of integrating pharmacodynamic changes into these protocols. Examples of completed pharmacokinetic studies in pregnancy are provided for illustration.

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.

Pharmacokinetic Evaluation in Pregnancy-Current Status and Future Considerations: Workshop Summary

As pregnant individuals have traditionally been excluded from clinical trials, there is a gap in knowledge at the time of drug approval regarding safety, efficacy, and appropriate dosing for most prescription medications used during pregnancy. Physiologic changes in pregnancy can result in changes in pharmacokinetics that can impact safety or efficacy. This highlights the need to foster further research and collection of pharmacokinetic data in pregnancy to ensure appropriate drug dosing in pregnant individuals. Therefore, the US Food and Drug Administration and the University of Maryland Center of Excellence in Regulatory Science and Innovation hosted a workshop on May 16 and 17, 2022, titled "Pharmacokinetic Evaluation in Pregnancy." This is a summary of the workshop proceedings.

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.

Antiseizure Medications in Pregnancy

Epilepsy affects up to 15 million of people assigned female at birth of childbearing age globally. Up to 65% of these people with epilepsy and gestational capacity have an unplanned pregnancy. Seizure control during pregnancy is important for both the childbearer's and fetus' safety. There are multiple antiseizure medications (ASMs) that can be used to control epilepsy; however, each medication has its own teratogenic risk profile, which must be considered. The majority of these ASMs will require frequent plasma concentration monitoring during pregnancy with corresponding dosage adjustments. Dosages can be reduced back to prepregnancy levels within 3 weeks postpartum. Breastfeeding on ASMs is recommended.

Principles of Obstetric Pharmacology: Maternal Physiologic and Hepatic Metabolism Changes

Since the recognition of pregnancy as a special pharmacokinetic population in the late 1990s, investigations have expanded our understanding of obstetric pharmacology. Many of the basic physiologic changes that occur during pregnancy impact on drug absorption, distribution, or clearance. Activities of hepatic metabolizing enzymes are variably altered by pregnancy, resulting in concentrations sufficiently different for some drugs that efficacy or toxicity may be affected. Understanding these unique pharmacologic changes will better inform our use of medications for our pregnant patients.

Gender Issues in Epileptic Patients

Treatment approaches for epilepsy for both women and men are similar, however, there are special aspects that must be considered when caring for women with epilepsy. This includes how hormonal fluctuations may affect seizure frequency, contraception, and potential drug-drug interactions, and pregnancy planning to minimize and potentially mitigate any adverse neurodevelopmental outcomes and major congenital malformations. Adequate counseling for women across the lifespan can help prepare women for the future and optimize outcomes.

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.

Dosage Optimization of Lamotrigine in Pregnancy: A Pharmacometric Approach using Modeling and Simulation

Lamotrigine is the most widely used anti-epileptic drug in pregnancy due to its low teratogenicity. However, there is an increased metabolism & clearance of Lamotrigine in pregnancy contributing to suboptimal drug therapy and poor disease control, prompting the need for pro-active dosage adjustments. The present study aimed to develop a pharmacometric model-based framework for recommending optimal dosage regimen for Lamotrigine in pregnancy. A systematic review was performed to obtain the literature aggregate data on clearance of Lamotrigine in pregnancy. The data was incorporated into simulations using PUMAS software for estimating the plasma concentrations at preconception stage and three trimesters. Simulated drug-exposures for different doses were investigated to ascertain plasma concentrations similar to the pre-conception and above minimum effective concentration. The simulated mean steady state trough plasma concentrations (mg/L) of Lamotrigine in non-pregnant and pregnant women at 3 trimesters decreased significantly (p<0.001) viz. 4.31±1.14, 3.17± 0.93, 2.14±0.86, 1.51±0.65 respectively. The simulation studies revealed that 150mg, 175mg, 225mg and 250mg twice daily doses, in pre-conception stage and three trimesters respectively achieve the target concentrations. Thus, the model-informed dosage regimen of Lamotrigine proposed in this study shall be considered to initiate the dosing in pregnant women, however the safety and efficacy of the drug have to be assured through therapeutic drug monitoring, in order to avoid therapeutic failure of Lamotrigine in pregnancy. This article is protected by copyright. All rights reserved.

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.

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.

Epilepsy and Pregnancy

PURPOSE OF REVIEW

Seizure disorders are the most frequent major neurologic complication in pregnancy, affecting 0.3% to 0.8% of all gestations. Women of childbearing age with epilepsy require special care related to pregnancy. This article provides up-to-date information to guide practitioners in the management of epilepsy in pregnancy.

RECENT FINDINGS

Ongoing multicenter pregnancy registries and studies continue to provide important information on issues related to pregnancy in women with epilepsy. Valproate poses a special risk for malformations and cognitive/behavioral impairments. A few antiseizure medications pose low risks (eg, lamotrigine, levetiracetam), but the risks for many antiseizure medications remain uncertain. Although pregnancy rates differ, a prospective study found no difference in fertility rates between women with epilepsy who were attempting to get pregnant and healthy controls. During pregnancy, folic acid supplementation is important, and a dose greater than 400 mcg/d during early pregnancy (ie, first 12 weeks) is associated with better neurodevelopmental outcome in children of women with epilepsy. Breastfeeding is not harmful and should be encouraged in women with epilepsy even when they are on antiseizure medication treatment.

SUMMARY

Women with epilepsy should be counseled early and regularly about reproductive health. Practitioners should discuss the risks of various obstetric complications; potential anatomic teratogenicity and neurodevelopmental dysfunction related to fetal antiseizure medication exposure; and a plan of care during pregnancy, delivery, and postpartum. Women with epilepsy should also be reassured that the majority of pregnancies are uneventful.

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.

Application of a Physiologically Based Pharmacokinetic Approach to Predict Theophylline Pharmacokinetics Using Virtual Non-Pregnant, Pregnant, Fetal, Breast-Feeding, and Neonatal Populations

Perinatal pharmacology is influenced by a myriad of physiological variables that are changing dynamically. The influence of these covariates has not been assessed systemically. The objective of this work was to use theophylline as a model drug and to predict its pharmacokinetics before, during (including prediction of the umbilical cord level), and after pregnancy as well as in milk (after single and multiple doses) and in neonates using a physiological-based pharmacokinetic (PBPK) model. Neonatal theophylline exposure from milk consumption was projected in both normal term and preterm subjects. Predicted infant daily doses were calculated using theophylline average and maximum concentration in the milk as well as an estimate of milk consumption. Predicted concentrations and parameters from the PBPK model were compared to the observed data. PBPK predicted theophylline concentrations in non-pregnant and pregnant populations at different gestational weeks were within 2-fold of the observations and the observed concentrations fell within the 5th-95th prediction interval from the PBPK simulations. The PBPK model predicted an average cord-to-maternal plasma ratio of 1.0, which also agrees well with experimental observations. Predicted postpartum theophylline concentration profiles in milk were also in good agreement with observations with a predicted milk-to-plasma ratio of 0.68. For an infant of 2 kg consuming 150 ml of milk per day, the lactation model predicted a relative infant dose (RID) of 12 and 17% using predicted average (C_avg,ss) and maximum (C_max,ss) concentration in milk at steady state. The maximum RID of 17% corresponds to an absolute infant daily dose of 1.4 ± 0.5 mg/kg/day. This dose, when administered as 0.233 mg/kg every 4 h, to resemble breastfeeding frequency, resulted in plasma concentrations as high as 3.9 (1.9-6.8) mg/L and 2.8 (1.3-5.3) (5th-95th percentiles) on day 7 in preterm (32 GW) and full-term neonatal populations.

Clearance of buprenorphine during pregnancy and neonatal outcomes

Buprenorphine is emerging as the preferred pharmacologic treatment for opioid use disorder during pregnancy. We examined the relative plasma clearance of buprenorphine (BUP) across pregnancy. Pregnant women with opioid use disorder participating in a prospective, observational study from 2013 to 2016 on stress in pregnancy who were receiving BUP for opioid use disorder were included. Women with an active eating disorder or suicidal ideation were excluded. Research visits occurred at 4-6-week intervals across pregnancy and the early postpartum period and included medication exposure history and blood samples. All assays for BUP serum concentrations at steady state were completed. Relative weight-adjusted clearance (Cl) was calculated using Cl = (daily dose [mg]/ body weight [kg])/serum concentration [ng/ml]. We collected 112 maternal blood samples from 29 women throughout pregnancy and the postpartum period. Serum concentrations for BUP ranged from < 0.2 to 15.8 ng/ml. Eleven women, with greater than three collected samples, increased their daily dose of BUP during pregnancy; however, there were no significant differences in relative clearance of BUP across this same period. This data suggests that women with opioid use disorder receiving BUP did not demonstrate a significant increase in BUP clearance across pregnancy despite increase in dosages during pregnancy. When selecting an appropriate BUP dosage for management of perinatal opioid use disorder, gestational stage appears not to be an important covariate and should be based on an individualized approach.

Levetiracetam, lamotrigine and carbamazepine: which monotherapy during pregnancy?

OBJECTIVE

Epilepsy treatment during pregnancy is still challenging. The study is aimed at comparing the efficacy and safety of carbamazepine (CBZ), lamotrigine (LTG) and levetiracetam (LEV) monotherapies during pregnancy in women with focal (FE) or generalized (GE) epilepsy.

METHODS

A multicentre retrospective study was conducted to evaluate seizures frequency and seizure freedom (SF) rate during 3 months before pregnancy, each trimester of gestation and post-partum period in women on monotherapy with CBZ, LTG and LEV.

RESULTS

Fifty-seven pregnancies (45 FE, 12 GE) on monotherapy (29 CBZ, 11 LTG, 17 LEV) were included. A significant reduction of seizure frequency was found in the first trimester of pregnancy as compared with that one before pregnancy (p = 0.004), more evident in GE (p = 0.003) and in LEV group (p = 0.004). The SF rate significantly increased in the first trimester in comparison to that one before pregnancy and persisted in the post-partum period in the whole sample (p < 0.001) and in women on LEV (p = 0.004). Besides, 88.57% of SF women before pregnancy remained unchanged during gestation and the post-partum period. One major heart malformation in CBZ and no major malformations in LTG and LEV groups were found.

CONCLUSIONS

A better clinical outcome during pregnancy emerged since the first trimester in comparison to the before-pregnancy period, mostly evident in women with GE and LEV therapy, reinforcing the hypothesis of a protective role of pregnancy versus seizures. SF before pregnancy represents a significant predictive factor of good clinical outcome during gestation and the post-partum period. Compared to CBZ, LTG and LEV showed a better safety profile.

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.

Precision medicine in women with epilepsy: The challenge, systematic review, and future direction

Epilepsy is one of the most prevalent neurologic conditions, affecting almost 70 million people worldwide. In the United States, 1.3 million women with epilepsy (WWE) are in their active reproductive years. Women with epilepsy (WWE) face gender-specific challenges such as pregnancy, seizure exacerbation with hormonal pattern fluctuations, contraception, fertility, and menopause. Precision medicine, which applies state-of-the art molecular profiling to diagnostic, prognostic, and therapeutic problems, has the potential to advance the care of WWE by precisely tailoring individualized management to each patient's needs. For example, antiseizure medications (ASMs) are among the most common teratogens prescribed to women of childbearing potential. Teratogens act in a dose-dependent manner on a susceptible genotype. However, the genotypes at risk for ASM-induced teratogenic deficits are unknown. Here we summarize current challenging issues for WWE, review the state-of-art tools for clinical precision medicine approaches, perform a systematic review of pharmacogenomic approaches in management for WWE, and discuss potential future directions in this field. We envision a future in which precision medicine enables a new practice style that puts focus on early detection, prediction, and targeted therapies for WWE.

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.

Population Pharmacokinetics of Levetiracetam: A Systematic Review

BACKGROUND

Levetiracetam has been widely used as a treatment option for different types of epilepsy in both adults and children. Because of its large between-subject variability, several population pharmacokinetic studies have been performed to identify its pharmacokinetic covariates, and thus facilitate individualised therapy.

OBJECTIVE

The aim of this review was to provide a synopsis for population pharmacokinetic studies of levetiracetam and explore the identified influencing covariates.

METHODS

We systematically searched the PubMed and Embase databases from inception to 30 June 2020. The information on study designs, target population, model characteristics, and identified covariates was summarised. Moreover, the pharmacokinetic profiles were compared among neonates, children, and adults.

RESULTS

Fourteen studies were included, among which two involved neonates, four involved children, two involved both children and adults, and six involved adults only. The median value of apparent clearance for children (0.074 L/h/kg [range 0.038-0.079]) was higher than that for adults (0.054 L/h/kg [range 0.039-0.061]). Body weight was found to significantly influence the apparent clearance and volume of distribution, whereas renal function influenced the clearance. Likewise, coadministration with enzyme-inducing antiepileptic drugs (such as carbamazepine and phenytoin) increased the drug clearance by 9-22%, whereas coadministration with valproate acid decreased it by 18.8%.

CONCLUSION

Levetiracetam dose regimen is dependent on the body size and renal function of patients. Further studies are needed to evaluate levetiracetam pharmacokinetics in neonates and pregnant women.

Efficacy and safety of lamotrigine in the treatment of bipolar disorder across the lifespan: a systematic review

BACKGROUND

Bipolar disorder (BD) is a cyclic mood disorder characterised by alternating episodes of mania/hypomania and depression interspersed with euthymic periods. Lamotrigine (LTG) demonstrated some mood improvement in patients treated for epilepsy, leading to clinical studies in patients with BD and its eventual introduction as maintenance therapy for the prevention of depressive relapse in euthymic patients. Most current clinical guidelines include LTG as a recommended treatment option for the maintenance phase in adult BD, consistent with its global licencing status.

AIMS

To review the evidence for the efficacy and safety of LTG in the treatment of all phases of BD.

METHODS

PubMed was searched for double-blind, randomised, placebo-controlled trials using the keywords: LTG, Lamictal, 'bipolar disorder', 'bipolar affective disorder', 'bipolar I', 'bipolar II', cyclothymia, mania, manic, depression, depressive, 'randomised controlled trial', 'randomised trial', RCT and 'placebo-controlled' and corresponding MeSH terms. Eligible articles published in English were reviewed.

RESULTS

Thirteen studies were identified. The strongest evidence supports utility in the prevention of recurrence and relapse, particularly depressive relapse, in stabilised patients. Some evidence suggests efficacy in acute bipolar depression, but findings are inconsistent. There is little or no strong evidence in support of efficacy in acute mania, unipolar depression, or rapid-cycling BD. Few controlled trials have evaluated LTG in bipolar II or in paediatric patients. Indications for safety, tolerability and patient acceptability are relatively favourable, provided there is slow dose escalation to reduce the probability of skin rash.

CONCLUSION

On the balance of efficacy and tolerability, LTG might be considered a first-line drug for BD, except for acute manic episodes or where rapid symptom control is required. In terms of efficacy alone, however, the evidence favours other medications.

Contraceptive vaginal ring reduces lamotrigine levels

OBJECTIVE

The objective of the study was to describe the effect of the vaginal ring and transdermal patch on lamotrigine serum levels in women with epilepsy.

BACKGROUND

Previous studies demonstrate that oral hormonal contraceptives containing synthetic estrogen increase lamotrigine clearance through induction of glucuronidation. This leads to variable lamotrigine serum concentrations throughout monthly cycles in women who are on combined oral contraceptives (COCs). The effects of estrogen-containing nonoral hormonal contraceptive methods, including the vaginal ring and transdermal patch, on lamotrigine pharmacokinetics are not well described.

METHODS

Retrospective chart review was performed to identify serum lamotrigine levels drawn from women with epilepsy while on the active phase of vaginal ring or transdermal patch and while off contraception. Wilcoxon signed-rank tests for paired data were used to compare the difference in dose-corrected lamotrigine concentration in plasma between values while on hormonal contraception to those while off contraception in patients using a vaginal ring.

RESULTS

Six patients were using the vaginal ring, and one patient was using the transdermal patch. Lamotrigine dose-corrected concentrations were decreased during the active phase of the vaginal ring compared with concentrations during the period off contraception (p = .04). There was one patient without a decrease in concentration, but the other five patients on the vaginal ring had a decrease in dose-corrected lamotrigine concentration ranging from 36 to 70% while on the vaginal ring. Similarly, one patient using the transdermal patch had a decrease of 37% in dose-corrected lamotrigine concentration while on the patch.

CONCLUSIONS

The findings support that the vaginal ring contraceptive method decreases lamotrigine concentrations during the active phase of treatment. This has important implications for contraceptive counseling and maintaining therapeutic levels in women of childbearing age with epilepsy.

Antiepileptic Drug Exposure in Infants of Breastfeeding Mothers With Epilepsy

Importance

There is limited information on infant drug exposure via breastfeeding by mothers who are receiving antiepileptic drug therapy.

Objective

To provide direct, objective information on antiepileptic drug exposure through breast milk.

Design, Setting, and Participants

This prospective cohort study was conducted between December 2012 to October 2016, with follow-up in children until 6 years of age at 20 sites across the United States. Data were collected via an observational multicenter investigation (Maternal Outcomes and Neurodevelopmental Effects of Antiepileptic Drugs [MONEAD]) of outcomes in pregnant mothers with epilepsy and their children. Pregnant women with epilepsy who were aged 14 to 45 years, had pregnancies that had progressed to less than 20 weeks' gestational age, and had measured IQ scores of more than 70 points were enrolled and followed up through pregnancy and 9 postpartum months. Their infants were enrolled at birth. Data were analyzed from May 2014 to August 2019.

Exposures

Antiepileptic drug exposure in infants who were breastfed.

Main Outcomes and Measures

The percentage of infant-to-mother concentration of antiepileptic drugs. Antiepileptic drug concentrations were quantified from blood samples collected from infants and mothers at the same visit, 5 to 20 weeks after birth. Concentrations of antiepileptic drugs in infants at less than the lower limit of quantification were assessed as half of the lower limit. Additional measures collected were the total duration of all daily breastfeeding sessions and/or the volume of pumped breast milk ingested from a bottle.

Results

A total of 351 women (of 865 screened and 503 eligible individuals) were enrolled, along with their 345 infants (179 female children [51.9%]; median [range] age, 13 [5-20] weeks). Of the 345 infants, 222 (64.3%) were breastfed; the data collection yielded 164 matching infant-mother concentration pairs from 138 infants. Approximately 49% of all antiepileptic drug concentrations in nursing infants were less than the lower limit of quantification. The median percentage of infant-to-mother concentration for all 7 antiepileptic drugs and 1 metabolite (carbamazepine, carbamazepine-10,11-epoxide, levetiracetam, lamotrigine, oxcarbazepine, topiramate, valproate, and zonisamide) ranged from 0.3% (range, 0.2%-0.9%) to 44.2% (range, 35.2%-125.3%). In multiple linear regression models, maternal concentration was a significant factor associated with lamotrigine concentration in infants (Pearson correlation coefficient, 0.58; P < .001) but not levetiracetam concentration in infants.

Conclusions and Relevance

Overall, antiepileptic drug concentrations in blood samples of infants who were breastfed were substantially lower than maternal blood concentrations. Given the well-known benefits of breastfeeding and the prior studies demonstrating no ill effects when the mother was receiving antiepileptic drugs, these findings support the breastfeeding of infants by mothers with epilepsy who are taking antiepileptic drug therapy.

Drugs in pregnancy: Pharmacologic and physiologic changes that affect clinical care

Pharmacologic interventions play a major role in obstetrical care throughout pregnancy, labor and delivery and the postpartum. Traditionally, obstetrical providers have utilized standard dosing regimens developed for non-obstetrical indications based on pharmacokinetic knowledge from studies in men or non-pregnant women. With the recognition of pregnancy as a special pharmacokinetic population in the late 1990s, investigators have begun to study drug disposition in this unique patient dyad. Many of the basic physiologic changes that occur during pregnancy have significant impact on drug absorption, distribution and clearance. Activity of Phase I and Phase II drug metabolizing enzymes are differentially altered by pregnancy, resulting in drug concentrations sufficiently different for some medications that efficacy or toxicity is affected. Placental transporters play a major dynamic role in determining fetal drug exposure. In the past two decades, we have begun to expand our understanding of obstetrical pharmacology; however, to truly optimize pharmacologic care of our pregnant patients and their developing fetus, additional research is critically needed.

Psychotropic drug use in perinatal women with bipolar disorder

Optimal dose management of psychotropic drugs during the perinatal period reduces the risk for recurrence of mood episodes in women with Bipolar Disorder. Physiological changes during pregnancy are associated with decreases in the plasma concentrations of the majority of mood stabilizing medications. Regular symptom and drug concentration monitoring for lithium and anticonvulsants with reflexive dose adjustment improves the probability of sustained symptom remission across pregnancy. The elimination clearance trajectory across pregnancy for psychotropics dictates the frequency of laboratory monitoring and dose adjustment. The literature on the pharmacokinetics of lithium, lamotrigine, carbamazepine and atypical antipsychotics during pregnancy and postpartum are reviewed, recommendations for symptom and laboratory monitoring are proposed and recommendations for dose adjustments are presented.

Pharmacogenomics in pregnancy

Pregnant women frequently take prescription and over the counter medications. The efficacy of medications is affected by the many physiological changes during pregnancy, and these events may be further impacted by genetic factors. Research on pharmacogenomic and pharmacokinetic influences on drug disposition during pregnancy has lagged behind other fields. Clinical investigators have demonstrated altered activity of several drug metabolizing enzymes during pregnancy. Emerging evidence also supports the influence of pharmacogenomic variability in drug response for many important classes of drugs commonly used in pregnancy. Prescribing medications during pregnancy requires an understanding of the substantial dynamic physiologic and metabolic changes that occur during gestation. Pharmacogenomics also contributes to the inter-individual variability in response to many medications, and more research is needed to understand how best to manage drug therapy in pregnant women.

Clinical Advances in Sex- and Gender-Informed Medicine to Improve the Health of All: A Review

IMPORTANCE

Biological sex and sociocultural gender represent major sources of diversity among patients, and recent research has shown the association of sex and gender with health. A growing body of literature describes widespread associations of sex and gender with cells, organs, and the manner in which individual patients interact with health care systems. Sex- and gender-informed medicine is a young paradigm of clinical practice and medical research founded on this literature that considers the association of sex and gender with each element of the disease process from risk, to presentation, to response to therapy.

OBSERVATIONS

Characteristics that underlie sex and gender involve both endogenous and exogenous factors that change throughout the life course. This review details clinical examples with broad applicability that highlight sex and gender differences in the key domains of genetics, epigenomic modifiers, hormonal milieu, immune function, neurocognitive aging process, vascular health, response to therapeutics, and interaction with health care systems. These domains interact with one another in multidimensional associations, contributing to the diversity of the sex and gender spectra. Novel research has identified differences of clinical relevance with the potential to improve care for all patients.

CONCLUSIONS AND RELEVANCE

Clinicians should consider incorporating sex and gender in their decision-making to practice precision medicine that integrates fundamental components of patient individuality. Recognizing the biological and environmental factors that affect the disease course is imperative to optimizing care for each patient. Research highlights the myriad ways sex and gender play a role in health and disease. However, these clinically relevant insights have yet to be systematically incorporated into care. The framework described in this review serves as a guide to help clinicians consider sex and gender as they practice precision medicine.

Epilepsy

The management of epilepsy during pregnancy involves optimizing seizure control for the mother, while ensuring the best outcome for the developing fetus. Preconception counseling regarding contraception, folic acid, and antiseizure medications (ASMs) will maximize positive outcomes. Folic acid supplementation is recommended to decrease risk of neural tube defects, similar to the general population, and has been associated with improved cognitive outcomes and decreased risk of autistic traits in offspring. Efforts should be made to optimize the ASM regimen before pregnancy to the fewest number of ASMs, lowest effective doses, with avoidance of more teratogenic agents such as valproic acid. Valproic acid is associated with the highest increased risk of major congenital malformations, as well as reduced cognitive outcomes and neurodevelopmental disorders. Decreasing or changing ASMs during pregnancy should be done with caution, as convulsive seizures have been associated with adverse fetal outcomes including cognitive impairment. Physiologic changes during pregnancy affect ASM levels and in turn, risk for seizures, necessitating frequent monitoring of ASM serum concentrations. Mothers should also be counseled postpartum about how the benefits of breastfeeding outweigh the transmission of medication into breast milk. Communication between providers (obstetrics and neurology) and pregnant women with epilepsy is essential.

Psychotropic Treatment During Pregnancy: Research Synthesis and Clinical Care Principles

Background: Psychiatric illnesses are common in women of childbearing age. The perinatal period is a particularly high-risk time for depression, bipolar, and anxiety disorders. Methods: The scope of the public health problem of perinatal mental disorders is discussed followed by an examination of the specific research methods utilized for the study of birth and developmental outcomes associated with maternal mental illness and its treatment. The evidence on exposure to common psychotropics during pregnancy and breastfeeding is reviewed. Results: Selective serotonin reuptake inhibitors or serotonin-norepinephrine reuptake inhibitor medications are not associated with higher rates of birth defects or long-term changes in mental development after adjustment for confounding factors associated with underlying psychiatric illness. Lithium exposure is associated with an increased risk for fetal cardiac malformations, but this risk is lower than previously thought (absolute risk of Ebstein's anomaly 6/1,000). Antipsychotics, other than risperidone and potentially paliperidone, have not been associated with an increase in birth defects; olanzapine and quetiapine have been linked with an elevated risk of gestational diabetes. Due to the dramatic physiological changes of pregnancy and enhanced hepatic metabolism, drug doses may need to be adjusted during pregnancy to sustain efficacy. Untreated maternal psychiatric illness also carries substantial risks for the mother, fetus, infant, and family. Conclusions: The goal of perinatal mental health treatment is to optimally provide pharmacotherapy to mitigate the somatic and psychosocial burdens of maternal psychiatric disorders. Regular symptom monitoring during pregnancy and postpartum and medication dose adjustments to sustain efficacy constitutes good practice.

Pharmacokinetic changes and therapeutic drug monitoring of lamotrigine during pregnancy

OBJECTIVES

To evaluate the pharmacokinetic changes in lamotrigine (LTG) from prepregnancy to postpartum and to assess the impact of therapeutic drug monitoring (TDM) on seizure management during pregnancy in a Chinese population.

METHODS

A series of women who were on LTG monotherapy before conception or during pregnancy were included in this retrospective study. The clinical characteristics of the mothers and fetuses were collected. The apparent clearance (AC) and the ratio to target concentration (RTC) were calculated for each trimester or for each month. RTCs were compared between patients with and without an increase in the frequency of seizures. A receiver operating characteristic curve to determine the RTC threshold, which predicts increased seizure frequency best, was drawn.

RESULTS

A total of 12 patients and their 12 pregnancies were reviewed retrospectively. AC increased by 82.5% during the first trimester (p = 0.0343), 203.2% during the second trimester (p = 0.0010), and 197.0% during the third trimester (p = 0.0061) compared with the prepregnancy level. The value returned to the prepregnancy level after delivery. Seven patients who had adequate baseline information were included to examine the association between serum LTG concentration and seizure frequency. The RTC values of patients with and without an increased frequency of seizures were significantly different (p = 0.0164), and increased seizure frequency was associated with a lower RTC. An RTC < 0.64 was a predictor of deteriorating seizures.

CONCLUSIONS

The pharmacokinetic changes in LTG during pregnancy displayed marked interpatient variation. TDM can support a rational treatment plan for LTG use during pregnancy. We recommend regular monitoring of LTG serum concentrations from prepregnancy to postpartum.

Development of visual predictive checks accounting for multimodal parameter distributions in mixture models

The assumption of interindividual variability being unimodally distributed in nonlinear mixed effects models does not hold when the population under study displays multimodal parameter distributions. Mixture models allow the identification of parameters characteristic to a subpopulation by describing these multimodalities. Visual predictive check (VPC) is a standard simulation based diagnostic tool, but not yet adapted to account for multimodal parameter distributions. Mixture model analysis provides the probability for an individual to belong to a subpopulation (IPmix) and the most likely subpopulation for an individual to belong to (MIXEST). Using simulated data examples, two implementation strategies were followed to split the data into subpopulations for the development of mixture model specific VPCs. The first strategy splits the observed and simulated data according to the MIXEST assignment. A shortcoming of the MIXEST-based allocation strategy was a biased allocation towards the dominating subpopulation. This shortcoming was avoided by splitting observed and simulated data according to the IPmix assignment. For illustration purpose, the approaches were also applied to an irinotecan mixture model demonstrating 36% lower clearance of irinotecan metabolite (SN-38) in individuals with UGT1A1 homo/heterozygote versus wild-type genotype. VPCs with segregated subpopulations were helpful in identifying model misspecifications which were not evident with standard VPCs. The new tool provides an enhanced power of evaluation of mixture models.

Treatment of Juvenile Myoclonic Epilepsy in Patients of Child-Bearing Potential

Juvenile myoclonic epilepsy (JME) is both a frequent and a very characteristic epileptic syndrome with female preponderance. Treatment of JME in women of childbearing potential must consider multiple factors such as desire for pregnancy, use of contraception, seizure control and previously used antiepileptic drugs (AEDs). Approximately 85% of cases are well controlled with valproate, which remains the reference AED in JME but is nowadays considered unsafe for the expecting mother and her fetus. The prescription of valproate is now severely restricted in women of childbearing potential but may still be considered, at the lowest possible dose and when pregnancies can be reliably planned, with temporary alternatives to valproate prescribed before fertilization. Alternatives have emerged, especially lamotrigine and levetiracetam, but also topiramate, zonisamide, and recently perampanel, but none of these AEDs can be considered fully safe in the context of pregnancy. In special settings, benzodiazepines and barbiturates may be useful. In some cases, combination therapy, especially lamotrigine and levetiracetam, may be useful or even required. However, lamotrigine may have the potential to aggravate JME, with promyoclonic effects. Carbamazepine, oxcarbazepine and phenytoin must be avoided. Valproate, levetiracetam, zonisamide, topiramate if the daily dose is ≤ 200 mg and perampanel if the daily dose is ≤ 10 mg do not affect combined hormonal contraception. Lamotrigine ≥ 300 mg/day has been shown to decrease levonorgestrel levels by 20% but does not compromise combined hormonal contraception. Patients with JME taking oral contraceptive should be counselled on the fact that the estrogenic component can reduce concentrations of lamotrigine by over 50%, putting patients at risk of increased seizures. Pregnancy is a therapeutic challenge, and the risk/benefit ratio for the mother and fetus must be considered when choosing the appropriate drug. Lamotrigine (< 325 mg daily in the European Registry of Antiepileptic Drugs in Pregnancy) and levetiracetam seem to be comparatively safer in pregnancy than other AEDs, especially topiramate and valproate. Plasma concentration of lamotrigine and levetiracetam decreases significantly during pregnancy, and dosage adjustments may be necessary. With persisting generalized tonic-clonic seizures, the combination of lamotrigine and levetiracetam offer the chance of seizure control and lesser risks of major congenital malformations. The risk of malformation increases when valproate or topiramate are included in the drug combination. In one study, the relative risk of autism and autism spectrum disorders (ASD) in children born to women with epilepsy (WWE) treated with valproate were, respectively, 5.2 for autism and 2.9 for ASD versus 2.12 for autism and 1.6 for ASD in WWE not treated with valproate. More studies are needed to assess the risk of autism with AEDs other than valproate. The current knowledge is that the risk appears to be double that in the general population. In patients with JME, valproate remains an essential and life-changing agent. The consequences of a lifetime of poorly controlled epilepsy need to be balanced against the teratogenic risks of valproate during limited times in a woman's life. The management of JME in WWE should include lifestyle interventions, with avoidance of sleep deprivation, and planned pregnancy.

Therapeutic strategies for treating epilepsy during pregnancy

INTRODUCTION

Counseling for women with epilepsy of childbearing potential surrounding pregnancy issues is of the utmost importance and should be done when antiepileptic medications are prescribed and reviewed regularly at clinic visits. Physicians must be familiar with risks associated with antiepileptic medication, and endeavor to minimize risks to a fetus while selecting best medications for epilepsy type.

AREAS COVERED

The authors discuss the role of folic acid, updated evidence relating to the occurrence of major congenital malformations and neurocognitive risks associated with antiepileptic medication. They also examine the rationale for monitoring drug levels, optimum delivery strategies, and evidence for the safety of breastfeeding while taking antiepileptic medication.

EXPERT OPINION

Valproate carries the highest known teratogenic risk in pregnancy and should only be prescribed to women of child-bearing potential in a specialist setting. There is a need for the ongoing register collection of risks associated with newer AEDs which lack substantial (major) data. Choosing these newer medications can create a dilemma for physicians, particularly when seizures are not well controlled or where treatment options are limited. The authors advocate a multidisciplinary team approach to managing women with epilepsy so that pregnancies in such women can be well managed in an optimum and individualized fashion.

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

OBJECTIVE

To characterize the magnitude and time course of pregnancy-related clearance changes for different antiepileptic drugs (AEDs): levetiracetam, oxcarbazepine, topiramate, phenytoin, and valproate. A secondary aim was to determine if a decreased AED serum concentration was associated with increased seizure frequency.

METHODS

Women with epilepsy were enrolled preconception or early in pregnancy and prospectively followed throughout pregnancy and the first postpartum year with daily diaries of AED doses, adherence, and seizures. Study visits with AED concentration measurements occurred every 1-3 months. AED clearances in each trimester were compared to nonpregnant baseline using a mixed linear regression model, with adjustments for age, race, and hours postdose. In women on monotherapy, 2-sample t test was used to compare the ratio to target concentrations (RTC) between women with seizure worsening each trimester and those without.

RESULTS

AED clearances were calculated for levetiracetam (n = 18 pregnancies), oxcarbazepine (n = 4), topiramate (n = 10), valproate (n = 5), and phenytoin (n = 7). Mean maximal clearances were reached for (1) levetiracetam in first trimester (1.71-fold baseline clearance) (p = 0.0001), (2) oxcarbazepine in second trimester (1.63-fold) (p = 0.0001), and (3) topiramate in second trimester (1.39-fold) (p = 0.025). In 15 women on AED monotherapy, increased seizure frequency in the first, second, and all trimesters was associated with a lower RTC (p < 0.05).

CONCLUSION

AED clearance significantly changes by the first trimester for levetiracetam and by the second trimester for oxcarbazepine and topiramate. Lower RTC was associated with seizure worsening. Early therapeutic drug monitoring and dose adjustment may be helpful to avoid increased seizure frequency.