Antiepileptic drug treatment in pregnancy: Changes in drug disposition and their clinical implications

Mechanisms of altered hepatic drug disposition during pregnancy: small molecules

INTRODUCTION

Pregnancy alters the systemic exposure and clearance of many hepatically cleared drugs that are commonly used by obstetric patients. Understanding the molecular mechanisms underlying the changes in factors that affect hepatic drug clearance (blood flow, protein binding, and intrinsic clearance) is essential to more precisely predict systemic drug exposure and dose requirements in obstetric patients.

AREAS COVERED

This review (1) summarizes the anatomic, physiologic, and biochemical changes in maternal hepatic, cardiovascular, endocrine, and renal systems relevant to hepatic drug clearance and (2) reviews the molecular mechanisms underlying the altered hepatic metabolism and intrinsic clearance of drugs during pregnancy via a comprehensive PubMed search. It also identifies knowledge gaps in the molecular mechanisms and factors that modulate hepatic drug clearance during pregnancy.

EXPERT OPINION

Pharmacokinetic studies have shown that pregnancy alters systemic exposure, protein binding, and clearance of many drugs during gestation in part due to pregnancy-associated decreases in plasma albumin, increases in organ blood flow, and changes in the activity of drug-metabolizing enzymes (DMEs) and transporters. The changes in the activity of certain DMEs and transporters during pregnancy are likely driven by hormonal-changes that inhibit their activity or alter the expression of these proteins through activation of transcription factors.

What do pharmacists know about epilepsy and antiseizure medications? - A survey among pharmacists in Norway

BACKGROUND

Approximately 45.000 persons in Norway have a diagnosis of epilepsy, a condition that may have a major impact on quality of life. Antiseizure medications (ASMs) are drugs with many pharmacological challenges. Pharmacists play an important role in the counselling of patients with chronic diseases. A recent initiative by the International League Against Epilepsy (ILAE) focuses on the active role of pharmacists in epilepsy care. This study aimed at evaluating the knowledge of Norwegian pharmacists on this subject and to identify possible knowledge gaps and need for further initiatives, education and training.

METHOD

A survey was developed based on previous studies and supplied with questions adapted to Norwegian pharmacists. Pharmacists were recruited through social media and members of pharmaceutical associations. The survey included socio-demographic and occupational information, questions on knowledge-based topics and the pharmacists' sense of confidence.

RESULTS

There were 113 responses, the majority from women (80%) working in community pharmacies (78%). The results showed an overall satisfactory level of knowledge about epilepsy, in line with similar surveys from other countries. In some more specific areas of ASMs, such as drug interactions, pharmacokinetic aspects, adverse effects and counselling patients, there is a need for improvement. Experience in counselling patients with epilepsy was significantly correlated with the pharmacists' sense of confidence.

CONCLUSION

Pharmacists in Norway have a satisfactory level of knowledge and confidence in counselling regarding main issues of epilepsy and treatment with ASMs, but some knowledge gaps were identified. More educational opportunities to close these gaps may facilitate the pharmacist's role in building health literacy for this patient group and improve drug safety.

Comparison of offspring outcomes in women with and without epilepsy

OBJECTIVE

The potential impact of antiseizure medications (ASMs) on abortion rate and bone metabolism in the offspring of pregnant women with epilepsy (WWE) is currently unknown. This research aimed to assess the potential risk by conducting a comparative analysis of bone metabolism-related indicators in the offspring of WWE.

METHODS

We retrospectively analyzed data from 83 epileptic parturients receiving antenatal care at our hospital and a co-operative hospital from January 1, 2012, to December 31, 2021, comparing them to a control group of 249 parturients. The study analyzed and compared the two groups' growth parameters, including delivery mode, femoral length, biparietal diameter, and birth weight. Differences in femoral length, biparietal diameter, and birth weight among different ASM groups were also examined.

RESULTS

WWE were more likely to undergo a cesarean section with a lower abortion rate (55.4% vs. 37.3%, P = 0.004). After adjusting for potential confounding variables, offspring femoral length in WWE was significantly reduced compared to the control group (6.812 cm vs. 6.923 cm, P < 0.0001). Moreover, those born to WWE using multiple ASMs had significantly reduced femoral and biparietal lengths compared to those whose mothers used a single ASM or none (P < 0.0001). Additionally, birth weight was significantly lower in offspring of WWE using multiple ASMs than those not using ASM (P < 0.05).

INTERPRETATION

WWE experienced fewer abortions but worse negative offspring outcomes. The bone metabolism of the offspring of WWE was decreased and exhibited shortened femoral length, particularly in those on multiple ASMs.

Glucuronidation of orally administered drugs and the value of nanocarriers in strategies for its overcome

The gastrointestinal tract (GIT) plays a pivotal role in the absorption of orally administered drugs, with the small intestine serving as the primary site due to its extensive surface area and specialized cell types, including enterocytes and M cells. After oral administration, drugs are generally transported via the portal vein to the liver, where they undergo first-pass metabolism. This process involves various enzymatic reactions, including glucuronidation, facilitated by uridine diphosphate-glucuronosyltransferase (UGT), a major phase 2 reaction in mammalian metabolism. UGTs conjugate glucuronic acid to a wide array of endogenous and exogenous substrates, enhancing their solubility and excretion, but significantly affecting the bioavailability and therapeutic efficacy of drugs. UGT enzymes are ubiquitously distributed across tissues, prominently in the liver, but also in the GIT, kidneys, brain, and other organs where they play crucial roles in xenobiotic metabolism. Species-specific differences in UGT expression and activity impact the selection of animal models for pharmacological studies. Various experimental models - ranging from computational simulations (in silico) to laboratory experiments (in vitro) and animal studies (in vivo) - are employed throughout drug discovery and development to evaluate drug metabolism, including UGT activity. Effective strategies to counter pre-systemic metabolism are critical for improving drug bioavailability. This review explores several approaches including prodrugs, co-administration of specific molecules or use of inhibiting excipients in formulations. Strategies incorporating these excipients in nanoformulations demonstrate notable increases in drug absorption and bioavailability. This review highlights the importance of targeted delivery systems and excipient selection in overcoming metabolic barriers, aiming to optimize drug efficacy and patient outcomes.

Development and internal validation of a prognostic model for predicting tonic-clonic seizures during pregnancy in women with epilepsy

BACKGROUND

We aim to develop a model to predict the probability of tonic-clonic seizures in women with epilepsy (WWE) at any point during pregnancy until six weeks postpartum.

METHODS

We conducted a screening of patients diagnosed with epilepsy and who were pregnant, at a tertiary hospital in China, during the period of 1 January 2010 to 31 December 2020. We then followed up with these patients for at least one year postpartum. A total of 271 eligible patients were included in the cohort. The outcome was the occurrence of a tonic-clonic seizure during pregnancy or within six weeks postpartum. Predictors were screened through univariate analysis, and models were fitted through multivariate logistic regression analysis. Further, we compared the WMU model with the AntiEpileptic drug Monitoring in PREgnancy (EMPiRE) model in terms of discrimination (the area under receiver operating characteristic curve [AUC]), accuracy (GiViTI calibration belt), decision curve analysis (DCA), net reclassification index (NRI), and integrated discrimination improvement (IDI). Finally, we plotted a nomogram of the WMU model.

RESULTS

Of the 271 pregnant WWE, 62 patients (22.9%) had the outcome. The WMU model included three predictors: age at the time of pregnancy, admission to hospital for seizures in previous pregnancy, and seizures in the 12 months before pregnancy. Compared to the EMPiRE model, the AUC value of the WMU model was higher (0.76 vs. 0.639, P < 0.05). GiViTI calibration belt showed that the predicted risks of the WMU model were mostly consistent with the observed risks. In terms of DCA, the WMU model revealed the highest net proportional benefit for predicted probability thresholds between 10% and 90%. Additionally, our model exhibited better reclassification performance than the EMPiRE model (NRI: 0.331, P < 0.01 and IDI: 0.129, P < 0.01).

CONCLUSION

We attempted to develop a prognostic model for predicting the risk of tonic-clonic seizures in pregnant WWE. The WMU model showed good performance, but without external validation, it is unclear whether WMU model could be generalized.

Adaptive Dosage Strategy of Levetiracetam in Chinese Epileptic Patients: Focus on Pregnant Women

There is presently no efficient dose individualization strategy for the use of antiseizure medications in epileptic pregnant patients. This study aimed to develop a population pharmacokinetics model for levetiracetam and propose a tailored adaptive individualized dosage strategy for epileptic pregnant patients. A total of 322 levetiracetam plasma concentrations from 238 patients with epilepsy were included, including 216 women with epilepsy (20.83% of whom were pregnant). The levetiracetam plasma concentration was measured using a validated ultra-performance liquid chromatography-tandem mass spectrometry assay, and the data were modeled using a nonlinear mixed-effects model. The resultant model served as the basis for simulating the dosage adjustment strategy. A one-compartment model with first-order elimination best described the pharmacokinetic data of levetiracetam. The apparent clearance (CL/F) was 3.43 L/h (95% CI 3.30-3.56) and the apparent volume of distribution was 43.7 L (95% CI 40.4-47.0) for a typical individual of 57.2 kg. Pregnancy and body weight were found to be significant covariates of CL/F of levetiracetam. The recommended regimen of levetiracetam could be predicted by the population pharmacokinetic model based on body weight, gestational age, and the daily dose of levetiracetam taken before 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.

Dose adjustment strategy of levetiracetam in pregnant patients with epilepsy: Case report and literature review

RATIONALE

Pregnant patients with epilepsy are prone to preterm delivery, stillbirth, or cesarean section, and their mortality rate is almost 10 times higher than that of normal pregnant women. The potential negative influences of antiepileptic drugs (AEDs) on the fetus are weighed against the necessity for achieving optimal control of seizures. Treatment with AEDs during pregnancy is a major challenge for pregnant women and healthcare teams.

PATIENT CONCERNS

This paper reports two cases of young women diagnosed with pregnancy and epilepsy.

INTERVENTION

The dose of levetiracetam was adjusted under the guidance of therapeutic drug monitoring to reduce the effects of seizures on the fetus and the incidence of reproductive toxicity caused by adverse drug reactions.

OUTCOMES

Epilepsy was well controlled in the two pregnant patients, and the newborns had no genetic disorders.

LESSONS

It is recommended to regularly monitor the serum LEV level in pregnant patients with epilepsy. This practice serves as a foundation for adjusting the drug treatment plan and offering more precise guidance for medication management during pregnancy.

Dose Monitoring of Lamotrigine Monotherapy in Pregnancy: Are Pregnant Women with Epilepsy Currently Optimally Managed? A Systematic Review

BACKGROUND

Lamotrigine monotherapy is the first-line treatment for epilepsy in pregnant women. However, altered pharmacokinetics during pregnancy can lead to suboptimal drug levels and increased seizure risk. This systematic review aimed to evaluate current therapeutic drug monitoring (TDM) strategies for lamotrigine monotherapy in pregnant women with epilepsy and provide guidance for monitoring and dose adjustments.

METHODS

A systematic search was performed using the Ovid-MEDLINE, Ovid-EMBASE, and Ovid-Cochrane Central Register of Controlled Trials databases. Studies were included if data on lamotrigine dosing, concentration, TDM strategies, efficacy, or safety were available.

RESULTS

Eleven studies were analyzed, revealing heterogeneity in outcomes with selective reporting of TDM strategies; however, clear similarities were observed. Blood samples were collected every 1-3 months during pregnancy to maintain prepregnancy baseline drug levels. Lamotrigine's apparent and relative clearance increased across trimesters, particularly in the second and third trimesters, coinciding with a period of increased seizure frequency and required dose adjustments. Details on dose adjustments were limited. Some studies have proposed using the threshold of the ratio to the target concentration to predict increased seizure risk. No distinct association was observed between adverse newborn outcomes and lamotrigine dose or serum concentration. Few maternal adverse effects have been reported after delivery, confirming the necessity of empirical postpartum tapering.

CONCLUSIONS

Further studies are required to establish evidence-based standardized protocols encompassing all aspects of TDM. Early interventions, such as empirical dose increases during pregnancy and postpartum tapering, and routine monitoring from preconception to the postpartum period may enhance seizure control, reducing the risk of breakthrough seizures for the mother and unborn child.

Pharmacokinetic characterisation of a valproate Autism Spectrum Disorder rat model in a context of co-exposure to α-Hexabromocyclododecane

Assessing the role of α-hexabromocyclododecane α-HBCDD as a factor of susceptibility for Autism Spectrum disorders by using valproic acid-exposed rat model (VPA) required characterizing VPA pharmacokinetic in the context of α-HBCDD-co-exposure in non-pregnant and pregnant rats. The animals were exposed to α-HBCDD by gavage (100 ng/kg/day) for 12 days. This was followed by a single intraperitoneal dose of VPA (500 mg/kg) or a daily oral dose of VPA (500 mg/kg) for 3 days. Exposure to α-HBCDD did not affect the pharmacokinetics of VPA in pregnant or non-pregnant rats. Surprisingly, VPA administration altered the pharmacokinetics of α-HBCDD. VPA also triggered higher foetal toxicity and lethality with the PO than IP route. α-HBCDD did not aggravate the embryotoxicity observed with VPA, regardless of the route of exposure. Based on this evidence, a single administration of 500 mg/kg IP is the most suitable VPA model to investigate α-HBCDD co-exposure.

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.

Issues of Women with Epilepsy and Suitable Antiseizure Drugs

Seizure aggravation in women with epilepsy (WWE) tends to occur at two specific times during the menstrual cycle: the perimenstrual phase and the ovulation period. Antiseizure drugs (ASDs), especially those that induce enzymes, can accelerate the metabolism of hormones in oral contraceptives, rendering them less effective. Estrogen in contraceptive pills increases the metabolism of lamotrigine. Physiological changes during pregnancy can significantly impact the pharmacokinetics of ASDs, potentially necessitating adjustments in dosage for women with epilepsy to maintain seizure control. The use of valproate in pregnant women is associated with the highest risk of major congenital malformations among ASDs. Risks of major congenital malformations associated with lamotrigine, levetiracetam, and oxcarbazepine were within the range reported in the general population. Exposure to valproate can lead to lower IQ in offspring. Reduced folic acid levels are linked to orofacial clefts, cardiovascular malformations, and urogenital and limb anomalies in WWE. Decreased folate levels are expected with the use of enzyme-inducing ASDs. However, a high dose of folate was associated with an increased risk of cancer in children of mothers with epilepsy. Most ASDs are generally considered safe for breastfeeding and should be encouraged. However, no single ASD is considered ideal for childbearing WWE. Lamotrigine and levetiracetam are relatively more suitable options for this situation.

Pharmacological aspects of antiseizure medications: From basic mechanisms to clinical considerations of drug interactions and use of therapeutic drug monitoring

Antiseizure medications (ASMs) are the cornerstone of treatment for patients with epilepsy. Several new ASMs have recently been introduced to the market, making it possible to better tailor the treatment of epilepsy, as well as other indications (psychiatry and pain disorders). For this group of drugs there are numerous pharmacological challenges, and updated knowledge on their pharmacodynamic and pharmacokinetic properties is, therefore, crucial for an optimal treatment outcome. This review focuses on educational approaches to the following learning outcomes as described by the International League Against Epilepsy (ILAE): To demonstrate knowledge of pharmacokinetics and pharmacodynamics, drug interactions with ASMs and with concomitant medications, and appropriate monitoring of ASM serum levels (therapeutic drug monitoring, TDM). Basic principles in pharmacology, pharmacokinetic variability, and clinically relevant approaches to manage drug interactions are discussed. Furthermore, recent improvements in analytical technology and sampling are described. Future directions point to the combined implementation of TDM with genetic panels for proper diagnosis, pharmacogenetic tests where relevant, and the use of biochemical markers that will all contribute to personalized treatment. These approaches are clinically relevant for an optimal treatment outcome with ASMs in various patient groups.

External validation of the AntiEpileptic Drug Monitoring in PREgnancy (EMPiRE) model for predicting seizures in pregnant women with epilepsy

BACKGROUND

The AntiEpileptic Drug Monitoring in PREgnancy (EMPiRE) model is the only available tool for predicting seizures in pregnant women with epilepsy (WWE) using anti-seizure medications (ASMs); however, its predictive performance requires validation. This study aimed to evaluate the predictive ability of this model in pregnant Chinese WWE and its potential usefulness in clinical practice.

METHODS

Data of the EMPiRE model were derived from the EMPiRE study, a prospective multicenter cohort study that recruited women on ASM monotherapy (lamotrigine, carbamazepine, phenytoin or levetiracetam) or polytherapy (lamotrigine with either carbamazepine, phenytoin or levetiracetam). Based on the applicable population of the EMPiRE model, we evaluated 280 patients registered in the Wenzhou Epilepsy Follow-up Registry Database from January 1, 2010, to December 31, 2020. A total of 158 eligible patients were included in the validation cohort. We collected data on the baseline characteristics of patients, eight predictors of the EMPiRE model and outcome events. The outcome was the occurrence of tonic-clonic or non-tonic-clonic seizures at any time in pregnancy up to 6 weeks postpartum. We used the equation of the EMPiRE model to obtain the predicted probabilities of seizures. The predictive ability of the EMPiRE model was quantified by the C-statistic (scale 0-1, values > 0.5 show discrimination), GiViTI calibration test and decision curve analysis (DCA).

RESULTS

Of 158 eligible patients, 96 patients (60.8%, 96/158) experienced one or more seizures at any time between pregnancy and 6 weeks postpartum. The EMPiRE model showed good discrimination with a C-statistic of 0.76 (95% confidence interval [CI] 0.70-0.84). The GiViTI calibration belt showed that the predicted probabilities, which ranged from 16 to 96% (95% CI), were lower than the actual probabilities. DCA indicated that the highest net proportional benefit was obtained for predicted probability thresholds of 15-18% and 54-96%.

CONCLUSIONS

The EMPiRE model could discriminate well between WWE with and without seizures during pregnancy and 6 weeks postpartum, but the risk of seizures may be underestimated. The limitations of the model for specific medication regimens may limit its real-world application. If the model is further improved, it will be incredibly valuable.

The broad-spectrum activity of perampanel: state of the art and future perspective of AMPA antagonism beyond epilepsy

Glutamate is the brain's main excitatory neurotransmitter. Glutamatergic neurons primarily compose basic neuronal networks, especially in the cortex. An imbalance of excitatory and inhibitory activities may result in epilepsy or other neurological and psychiatric conditions. Among glutamate receptors, AMPA receptors are the predominant mediator of glutamate-induced excitatory neurotransmission and dictate synaptic efficiency and plasticity by their numbers and/or properties. Therefore, they appear to be a major drug target for modulating several brain functions. Perampanel (PER) is a highly selective, noncompetitive AMPA antagonist approved in several countries worldwide for treating different types of seizures in various epileptic conditions. However, recent data show that PER can potentially address many other conditions within epilepsy and beyond. From this perspective, this review aims to examine the new preclinical and clinical studies-especially those produced from 2017 onwards-on AMPA antagonism and PER in conditions such as mesial temporal lobe epilepsy, idiopathic and genetic generalized epilepsy, brain tumor-related epilepsy, status epilepticus, rare epileptic syndromes, stroke, sleep, epilepsy-related migraine, cognitive impairment, autism, dementia, and other neurodegenerative diseases, as well as provide suggestions on future research agenda aimed at probing the possibility of treating these conditions with PER and/or other AMPA receptor antagonists.

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.

Teratogen Potential Evaluation of the Aqueous and Hydroalcoholic Leaf Extracts of Crataegus oxyacantha in Pregnancy Rats

Crataegus oxyacantha is used in the treatment of cardiovascular diseases. The aim of this study was to evaluate the transplacental genotoxicity effect of aqueous (AE) and hydroalcoholic extract (HE) of leaves C. oxyacantha in a rat model and the quantification of malondialdehyde (MDA) in the liver. Three different doses of the AE and HE of the C. oxyacantha leaf were administered orally (500, 1000 and 2000 mg/kg) to Wistar rats during 5 days through the pregnancy term (16-21 days), and sampling in rats occurred every 24 h during the last 6 days of gestation, while only one sample was taken in neonates at birth. A sample of the mother's and the neonate's liver was taken for the determination of MDA. The results show that, at the hepatic level, the evaluated doses of extracts C. oxyacantha in pregnant rats and their pups did not show cytotoxicity. However, the AE and HE generated cytotoxic and genotoxic damage in the short term. On the other hand, only the AE showed a teratogenic effect. Based on these results, the AE and HE of the C. oxyacantha leaf should not be administered during pregnancy.

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.

Application of PBPK modeling in predicting maternal and fetal pharmacokinetics of levetiracetam during pregnancy

Levetiracetam is currently being used to treat epilepsy in pregnant women. The plasma concentration of levetiracetam drops sharply during pregnancy, and the inability of pregnant women to maintain therapeutic concentrations can lead to seizures. This study aimed to predict the changes in fetal and maternal plasma exposure to levetiracetam during pregnancy and provide advice on dose adjustment. The physiology-based pharmacokinetics (PBPK) model was developed using PK-Sim and Mobi software, and validated following comparison of the observed plasma concentration and pharmacokinetic parameters. The levetiracetam PBPK model for mother and the fetus at various stages of pregnancy was successfully established and verified. Predictions indicated that the area under the steady-state concentration-time curve for levetiracetam decreased to 83, 62, and 67% of baseline values in the first, second, and third trimesters, respectively. Based on PBPK predictions, the recommended dose of levetiracetam is 1.2, 1.6, and 1.5 times the baseline dose in the first, second, and third trimesters, respectively, not exceeding 4000 mg/day in the third trimester due to fetal safety. The levetiracetam PBPK model for pregnancy was successfully developed and validated, and could provide alternative levetiracetam dosing regimens across the stages of pregnancy.

[Interactions between anti-seizure medications and recommendations for combination treatment]

Pharmacotherapy is the most important pillar in the treatment of epilepsies. In approximately 50% of epilepsy patients monotherapy with anti-seizure medications (ASM) is insufficient. The knowledge of specific drug interactions in combination therapies is essential to recognize and avoid adverse side effects up to relevant therapy risks, including loss of efficiency and intoxication. Interactions can be of a pharmacokinetic or pharmacodynamic nature. Some effects of interactions in combination therapies can also be advantageous. Therapeutic drug monitoring in serum is not necessary for all ASMs and should be used rationally: however, it should be performed consistently if the indications are present. This review article provides fundamental knowledge about the most relevant interactions between ASMs and the indications for therapeutic drug monitoring.

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.

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.

An individualized medication model of sodium valproate for patients with bipolar disorder based on machine learning and deep learning techniques

Valproic acid/sodium valproate (VPA) is a widely used anticonvulsant drug for maintenance treatment of bipolar disorders. In order to balance the efficacy and adverse events of VPA treatment, an individualized dose regimen is necessary. This study aimed to establish an individualized medication model of VPA for patients with bipolar disorder based on machine learning and deep learning techniques. The sequential forward selection (SFS) algorithm was applied for selecting a feature subset, and random forest was used for interpolating missing values. Then, we compared nine models using XGBoost, LightGBM, CatBoost, random forest, GBDT, SVM, logistic regression, ANN, and TabNet, and CatBoost was chosen to establish the individualized medication model with the best performance (accuracy = 0.85, AUC = 0.91, sensitivity = 0.85, and specificity = 0.83). Three important variables that correlated with VPA daily dose included VPA TDM value, antipsychotics, and indirect bilirubin. SHapley Additive exPlanations was applied to visually interpret their impacts on VPA daily dose. Last, the confusion matrix presented that predicting a daily dose of 0.5 g VPA had a precision of 55.56% and recall rate of 83.33%, and predicting a daily dose of 1 g VPA had a precision of 95.83% and a recall rate of 85.19%. In conclusion, the individualized medication model of VPA for patients with bipolar disorder based on CatBoost had a good prediction ability, which provides guidance for clinicians to propose the optimal medication regimen.

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.

Treatment and care of women with epilepsy before, during, and after pregnancy: a practical guide

Women with epilepsy (WWE) wishing for a child represent a highly relevant subgroup of epilepsy patients. The treating epileptologist needs to delineate the epilepsy syndrome and choose the appropriate anti-seizure medication (ASM) considering the main goal of seizure freedom, teratogenic risks, changes in drug metabolism during pregnancy and postpartum, demanding for up-titration during and down-titration after pregnancy. Folic acid or vitamin K supplements and breastfeeding are also discussed in this review. Lamotrigine and levetiracetam have the lowest teratogenic potential. Data on teratogenic risks are also favorable for oxcarbazepine, whereas topiramate tends to have an unfavorable profile. Valproate needs special emphasis. It is most effective in generalized seizures but should be avoided whenever possible due to its teratogenic effects and the negative impact on neuropsychological development of in utero-exposed children. Valproate still has its justification in patients not achieving seizure freedom with other ASMs or if a woman decides to or cannot become pregnant for any reason. When valproate is the most appropriate treatment option, the patient and caregiver must be fully informed of the risks associated with its use during pregnancies. Folate supplementation is recommended to reduce the risk of major congenital malformations. However, there is insufficient information to address the optimal dose and it is unclear whether higher doses offer greater protection. There is currently no general recommendation for a peripartum vitamin K prophylaxis. During pregnancy most ASMs (e.g. lamotrigine, oxcarbazepine, and levetiracetam) need to be increased to compensate for the decline in serum levels; exceptions are valproate and carbamazepine. Postpartum, baseline levels are reached relatively fast, and down-titration is performed empirically. Many ASMs in monotherapy are (moderately) safe for breastfeeding and women should be encouraged to do so. This review provides a practically oriented overview of the complex management of WWE before, during, and after pregnancy.

Sex-Related Differences in Pharmacological Response to CNS Drugs: A Narrative Review

In the last decades, both animal and human studies have neglected female subjects with the aim of evading a theorized intricacy of feminine hormonal status. However, clinical experience proves that pharmacological response may vary between the two sexes since pathophysiological dissimilarities between men and women significantly influence the pharmacokinetics and pharmacodynamics of drugs. Sex-related differences in central nervous system (CNS) medication are particularly challenging to assess due to the complexity of disease manifestation, drugs’ intricate mechanisms of action, and lack of trustworthy means of evaluating the clinical response to medication. Although many studies showed contrary results, it appears to be a general tendency towards a certain sex-related difference in each pharmacological class. Broadly, opioids seem to produce better analgesia in women especially when they are administered for a prolonged period of time. On the other hand, respiratory and gastrointestinal adverse drug reactions (ADRs) following morphine therapy are more prevalent among female patients. Regarding antidepressants, studies suggest that males might respond better to tricyclic antidepressants (TCAs), whereas females prefer selective serotonin reuptake inhibitors (SSRI), probably due to their tolerance to particular ADRs. In general, studies missed spotting any significant sex-related differences in the therapeutic effect of antiepileptic drugs (AED), but ADRs have sex variations in conjunction with sex hormones’ metabolism. On the subject of antipsychotic therapy, women appear to have a superior response to this pharmacological class, although there are also studies claiming the opposite. However, it seems that reported sex-related differences regarding ADRs are steadier: women are more at risk of developing various side effects, such as metabolic dysfunctions, cardiovascular disorders, and hyperprolactinemia. Taking all of the above into account, it seems that response to CNS drugs might be occasionally influenced by sex as a biological variable. Nonetheless, although for each pharmacological class, studies generally converge to a certain pattern, opposite outcomes are standing in the way of a clear consensus. Hence, the fact that so many studies are yielding conflicting results emphasizes once again the need to address sex-related differences in pharmacological response to drugs.

[Impact of pregnancy on drug pharmacokinetics: What implication in clinical practice?]

Physiological changes that occur during pregnancy in the maternal body can lead to alterations in the response to drugs in the mother. Pregnancy modifies the volume of distribution of drugs, their binding to plasma proteins, the activity of their metabolizing enzymes, and their elimination. However, to date, due to the dynamic and complex processes involved, adjustments to the dosage regimen during pregnancy remain impossible to standardize. Knowledge of these modifications will help to better understand the possible loss of drug efficacy during pregnancy, as well as anticipating the clinical and plasma monitoring of drugs with a low therapeutic margin.

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.

Effect of levetiracetam on the gene expression of placental transporters in a murine model

OBJECTIVE

Levetiracetam (LEV) is an antiseizure medication prescribed to women during childbearing age. The impact of LEV on placental transporters is poorly understood. This study aimed to assess the effect of LEV exposure on the messenger RNA (mRNA) expression of placental transporters for hormones and nutrients and to correlate their expression with the drug's serum concentration in pregnant mice.

METHODS

Studies were conducted on gestational days (GD) 13 and 18, following oral treatment with 100 mg/kg LEV or the vehicle every 24 h after weaning. Serum LEV measurements were performed by High-performance liquid chromatography with a UV detector (HPLC-UV). The weight, height, and width of the fetuses were also analyzed. In addition, the placental expression of transporters xCt, Lat1, Oatp4a1, Fr-α, Rfc, and Snat4 was evaluated through semi-quantitative real-time polymerase chain reaction (qPCR). The Kruskal-Wallis and the Mann-Whitney U tests were used to determine the statistical significance (p < .05). The correlation between serum LEV concentration and placental gene expression was evaluated using the Spearman test.

RESULTS

The weight, height, and width were lower in the fetuses exposed to LEV compared with the control group (p < .05). The number of fetuses was lower in the LEV-exposed group than in the control GD 13 group (p < .001). No significant differences were detected in the mRNA expression level at GD 13. At GD 18, the expression of Lat1, Oatp4a1, xCT, and Snat4 was higher in the group treated with LEV compared with the control group (p < .05), whereas the expression of Rfc was lower (p < .05). No correlation was identified between serum LEV concentrations and gene expression levels.

SIGNIFICANCE

The repression of the Rfc transcript by LEV at GD 18 suggests that the protein expression would be abolished contributing to the observed intrauterine growth restriction (IUGR). Furthermore, the significant increase in mRNA of xCt, Snat4, Oatp4a1, and Lat1 might be a compensatory mechanism for fetal survival at GD 18.

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.

Epilepsy in Pregnancy—Management Principles and Focus on Valproate

An estimated 60 million people worldwide suffer from epilepsy, half of whom are women. About one-third of women with epilepsy are of childbearing age. The childbirth rate in women with epilepsy is about 20–40% lower compared to that of the general population, which may be partly due to a lower number of these women being in relationships. Lower fertility in women with epilepsy may be linked to the disease itself, but it is mainly a result of the treatment provided. Valproate, as an antiepileptic drug inhibiting histone deacetylases, may affect the expression of genes associated with cell cycle control and cellular differentiation. Evidently, this drug is associated with the risk of malformations although other antiepileptic drugs (AEDs) may also trigger birth defects, however, to a lower degree. Valproate (and to a certain degree other AEDs) may induce autism spectrum disorders and attention deficit hyperactivity disorder. The main mechanism responsible for all negative effects of prenatal exposure to valproate seems inhibition of histone deacetylases. Animal studies show a reduction in the expression of genes involved in social behavior and an increase in hippocampal cytokines. Valproate-induced oxidative stress may also contribute to neural tube defects. Interestingly, paternal exposure to this AED in mice may trigger neurodevelopmental disorders as well although a population-based cohort study does not confirm this effect. To lower the risk of congenital malformations and neurodevelopmental disorders, a single AED at the optimal dose and supplementation with folic acid is recommended. VPA should be avoided in women of childbearing age and especially during pregnancy.

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.

Managing brain tumors in pregnancy: The oncologist's struggle with maternal-fetal conflict

The diagnosis of malignancy, particularly brain tumors, in pregnancy is uncommon but poses a complex dilemma for the management of both the patient and her fetus, as the interplay of disease with the physiological state of pregnancy affects both outcomes. The routine evaluations (symptomatology, imaging, and hormonal assessments) and treatments (surgery, radiation therapy, and chemotherapy) that are commonplace in brain tumor management may need to be omitted or modified keeping in mind the risk to offspring. Multidisciplinary care and extensive prenatal and perinatal counseling and monitoring are essential. In this review, we discuss the available data addressing these issues and factors which may affect considerations of therapeutic abortions, changes in surgical or medical practices, and outcomes thereof.

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.

Multi-omic strategies applied to the study of pharmacoresistance in mesial temporal lobe epilepsy

Mesial temporal lobe epilepsy (MTLE) is the most common type of focal epilepsy in adults, and hippocampal sclerosis (HS) is a frequent histopathological feature in patients with MTLE. Pharmacoresistance is present in at least one-third of patients with MTLE with HS (MTLE+HS). Several hypotheses have been proposed to explain the mechanisms of pharmacoresistance in epilepsy, including the effect of genetic and molecular factors. In recent years, the increased knowledge generated by high-throughput omic technologies has significantly improved the power of molecular genetic studies to discover new mechanisms leading to disease and response to treatment. In this review, we present and discuss the contribution of different omic modalities to understand the basic mechanisms determining pharmacoresistance in patients with MTLE+HS. We provide an overview and a critical discussion of the findings, limitations, new approaches, and future directions of these studies to improve the understanding of pharmacoresistance in MTLE+HS. However, it is important to point out that, as with other complex traits, pharmacoresistance to anti-seizure medications is likely a multifactorial condition in which gene-gene and gene-environment interactions play an important role. Thus, studies using multidimensional approaches are more likely to unravel these intricate biological processes.

Effect of anti-epileptic drugs on first trimester screening test results

OBJECTIVE

To evaluate first trimester screening test parameters in epileptic patients using anti-epileptic drugs.

MATERIALS AND METHODS

We retrospectively evaluated first trimester screening test results of 23 epileptic pregnant women using anti-epileptic drugs with a control group consisting of 92 healthy pregnancies. The anti-epileptic drugs used in this study were carbamazepine, levatiracetam, valproic acid and lamotrigine. Single drug or multi-drug regimens were used according to the clinical conditions. Patients with any known chronic or acute disease and drug usage were excluded from the study. Comparisons were performed via Mann-Whitney U test.

RESULTS

First trimester screening test biochemical markers were compared and maternal serum PAPP-A MoM values were found to be similar in study and control groups while β-hCG MoM values were significantly higher in pregnancies using epileptic drugs (p: 0,737 and p < 0.001, respectively).

CONCLUSION

Biochemical first trimester screening test results may be affected by anti-epileptic drug usage, which may lead to misinterpretation of the risk level. Thus, validation of MoM values should be necessary in order to obtain optimal results.

Maternal epilepsy- perinatal outcome and long-term neurological morbidity of the offspring: a population-based cohort study

PURPOSE

The current study was aimed to assess whether maternal epilepsy is linked to long-term neurological morbidity of the offspring, and to examine whether maternal epilepsy is associated with adverse pregnancy outcomes.

METHODS

A population-based cohort study was conducted comparing perinatal outcomes of women with and without epilepsy, including long-term neurological morbidity of the offspring. Both the exposed and unexposed groups were followed up to 18 years of age for neurological-related morbidity. To assess perinatal outcomes of women with epilepsy, generalized estimation equation (GEE) models were used to control for confounders. To compare the cumulative incidence of long-term neurological morbidity a Kaplan-Meier survival curve was used. A Cox proportional hazards model was built to control for confounders.

RESULTS

During the study period, 243,682 deliveries met the inclusion criteria; 711 (0.29%) were of mothers with epilepsy. Maternal epilepsy was noted as an independent risk factor for preterm delivery, cesarean delivery, and low birth weight using GEE models controlling for maternal age and parity. Offspring born to mothers with epilepsy had higher rates of long-term neurological morbidity (Kaplan-Meier log-rank test, p < 0.001). A Cox proportional hazards model, controlled for maternal age, hypertensive disorders, gestational age, and diabetes mellitus, demonstrated that being born to a mother with epilepsy was an independent risk factor for long-term neurological morbidity of the offspring (adjusted HR 2.7, 95% CI 2.12-3.56, p < 0.001).

CONCLUSIONS

The pregnancy of epileptic women is independently associated with the adverse perinatal outcome as well as a higher risk for long-term neurological morbidity of the offspring.

Psychoses of Epilepsy in Pregnancy: A Case Report

To discuss the unique relationship between psychosis and seizures in a young individual, who is also pregnant. Psychosis of epilepsy can present in multitude of ways, including pre-ictal, ictal, post-ictal, chronic interictal, and forced normalization psychosis.

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.

Therapeutic Drug Monitoring in Pregnant Patients

During pregnancy, there are several physiological changes during each trimester that can affect the absorption, distribution, metabolism, and elimination of drugs. Although there is a potential need to understand the pharmacokinetics and pharmacodynamics of drugs in pregnant patients, therapeutic drug monitoring is not well established for various drug classes due to ethical and safety concerns regarding the neonate. Potential risks from in utero drug exposure to the fetus may impact growth and development and may cause malformations or teratogenesis. The clinician must consider the benefits of drug treatment for the pregnant mother versus the risk to the fetus, before prescribing medications during pregnancy. The objective of this review is to aid clinicians, pharmacists, and laboratorians in understanding the pharmacokinetic and pharmacodynamic changes during pregnancy, to provide drug class recommendations for monitoring therapy throughout pregnancy via therapeutic drug monitoring, and to highlight the recent directives of governing agencies on maternal and fetal health.

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.

Perampanel and pregnancy

Objective

The objective was to summarize pregnancy and fetal/postnatal outcomes following maternal perampanel exposure using preclinical and clinical data, and to use physiologically based pharmacokinetic (PBPK) modeling to improve understanding of perampanel pharmacokinetics (PK) during pregnancy.

Methods

Preclinical developmental studies with perampanel were conducted in pregnant rats and rabbits. Clinical data were collated from the Eisai global perampanel safety database, comprising reports of perampanel exposure during pregnancy from routine clinical settings, interventional studies, and non‐interventional post‐marketing studies, searched for events coded to Medical Dictionary for Regulatory Activities (MedDRA) high‐level group terms of Pregnancy, Labor, Delivery, and Postpartum Conditions and/or the Standardized MedDRA Query terms of Congenital, Familiar, and Genetic Disorders. A PBPK model was used to predict clinical perampanel PK throughout pregnancy.

Results

Preclinical studies indicated that perampanel may be linked with post‐implantation loss and/or some specific physical development delays but not fertility and early embryonic development. As of August 31, 2018, 96 pregnancies in 90 women receiving perampanel had been reported. No concomitant medications were reported in 26 (28.9%) women taking perampanel. Overall, 43 pregnancies reached full term (all normal live births), 28 did not reach term (induced abortion, n = 18; spontaneous miscarriage, n = 6; incomplete spontaneous miscarriage, n = 2; premature delivery, n = 1; stillbirth [Fallot’s tetralogy], n = 1), 18 were lost to follow‐up, and seven were ongoing at data cut‐off. Adverse events were reported in five full‐term neonates (low Apgar score, n = 2; fatal neonatal aspiration, n = 1; cystic fibrosis and congenital deafness, n = 1; poor sucking reflex and shallow breathing, n = 1). PK simulations predicted perampanel exposure decreases throughout pregnancy and is up to four‐ and three‐fold lower towards the end of pregnancy compared with non‐pregnant women for total and unbound perampanel, respectively.

Significance

These data provide preliminary information on perampanel use during pregnancy and should be interpreted with caution. Further outcome data are required to estimate the prevalence of adverse pregnancy outcomes with perampanel exposure.

Management of brain tumors presenting in pregnancy: a case series and systematic review

Patients who present with brain tumors during pregnancy require unique imaging and neurosurgical, obstetrical, and anesthetic considerations. Here, we review the literature and discuss the management of patients who present with brain tumors during pregnancy. Between 2009 and 2019, 9 patients were diagnosed at our institution with brain tumors during pregnancy. Clinical information was extracted from the electronic medical records. The median age at presentation was 29 years (range, 25-38 years). The most common symptoms at presentation included headache (n=5), visual changes (n=4), hemiparesis (n=3), and seizures (n=3). The median gestational age at presentation was 20.5 weeks (range, 11-37 weeks). Of note, 8 patients (89%) delivered healthy newborns, and 1 patient terminated her pregnancy. In addition, 5 patients (56%) required neurosurgical procedures during pregnancy (gestational ages, 14-37 weeks) because of disease progression (n=2) or neurologic instability (n=3). There was 1 episode of postneurosurgery morbidity (pulmonary embolism [PE]) and no surgical maternal mortality. The median length of follow-up was 15 months (range, 6-45 months). In cases demonstrating unstable or progressive neurosurgical status past the point of fetal viability, neurosurgical intervention should be considered. The physiological and pharmacodynamic changes of pregnancy substantially affect anesthetic management. Pregnancy termination should be discussed and offered to the patient when aggressive disease necessitates immediate treatment and the fetal gestational age remains previable, although neurologically stable patients may be able to continue the pregnancy to term. Ultimately, pregnant patients with brain tumors require an individualized approach to their care under the guidance of a multidisciplinary team.

Sources of Interindividual Variability

The efficacy, safety, and tolerability of drugs are dependent on numerous factors that influence their disposition. A dose that is efficacious and safe for one individual may result in sub-therapeutic or toxic blood concentrations in others. A significant source of this variability in drug response is drug metabolism, where differences in presystemic and systemic biotransformation efficiency result in variable degrees of systemic exposure (e.g., AUC, C_max, and/or C_min) following administration of a fixed dose.Interindividual differences in drug biotransformation have been studied extensively. It is recognized that both intrinsic factors (e.g., genetics, age, sex, and disease states) and extrinsic factors (e.g., diet , chemical exposures from the environment, and the microbiome) play a significant role. For drug-metabolizing enzymes, genetic variation can result in the complete absence or enhanced expression of a functional enzyme. In addition, upregulation and downregulation of gene expression, in response to an altered cellular environment, can achieve the same range of metabolic function (phenotype), but often in a less predictable and time-dependent manner. Understanding the mechanistic basis for variability in drug disposition and response is essential if we are to move beyond the era of empirical, trial-and-error dose selection and into an age of personalized medicine that will improve outcomes in maintaining health and treating disease.

THE IMPACT OF ANTIEPILEPTIC TREATMENT IN PREGNANCY ON PERINATAL OUTCOME IN CROATIA - A SINGLE-CENTER STUDY

Pregnancy can alter the natural course of epilepsy and affect pharmacokinetic profile of antiepileptic drugs (AEDs) making therapeutic management more demanding. Since there is no relevant population-based study in Croatia to date, we conducted this research with the aim to observe antiepileptic treatment policy in pregnancy and to determine if the number of AEDs affects pregnancy outcomes. The study included all women with epilepsy with singleton pregnancy exposed to one or more AEDs divided into two groups (group 1: one AED and group 2: more than one AED used). Data were collected retrospectively at the Department of Obstetrics and Gynecology, Zagreb University Hospital Centre, Zagreb, Croatia, and included 153 women from January 2010 to December 2018. Primary outcomes included rates of preterm delivery, major fetal malformations, gestational hypertension, cesarean section rate, and appearance of seizures during pregnancy. We found higher rates of all pregnancy complications examined than in the general population, while comparison of the two study groups yielded significant differences. Preterm labor was detected in 30% of deliveries in polytherapy group compared to 16.6% in monotherapy group (p=0.03). Gestational hypertension was recorded in 20% of women in polytherapy group vs. 4.90% in monotherapy group (p=0.009). There was also a high rate of cesarean deliveries in polytherapy group (27.5%). Seizures during pregnancy occurred in 48.4% of patients in polytherapy group, which was significantly higher than the rate recorded in monotherapy group (p=0.015). In this single-center retrospective study, women with epilepsy using AEDs during pregnancy had a higher rate of gestational hypertension and preterm delivery than the general population of pregnant women. To the best of our knowledge, this is the first study in Croatia observing antiepileptic treatment policy in pregnancy with regards to AED regimen and perinatal outcome.

Epilepsy: Workup and Management in Adults

When managing epilepsy, there is a temptation to focus care with respect to the last and the next seizure. However, epilepsy is a multifaceted chronic condition and should be treated as such. Epilepsy comes with many physical risks, psychological effects, and socioeconomic ramifications, demanding a long-term commitment from the treating physician. Patients with epilepsy, compared to other chronically ill patient populations, have a worse quality of life, family function, and less social support. The majority of patients are well controlled on antiseizure drugs. However, approximately one-third will continue to have seizures despite optimized medical management. The primary aim of this article is to explore the long-term management of chronic epilepsy, and to address some of the particular needs of patients with chronic epilepsy.