Antiepileptic drugs and pregnancy outcomes

Teratogenic medications and concurrent contraceptive use in women of childbearing ability with epilepsy

BACKGROUND

Many antiepileptic drugs (AEDs) have the potential to cause teratogenicity. We evaluated eight antiepileptic drugs (AEDs) classified as Federal Drug Administration (FDA) pregnancy category D, X, or N designations and having documented teratogenic effects. These include carbamazepine, ethosuximide, fosphenytoin, phenobarbital, phenytoin, primidone, topiramate, and valproate. Women with epilepsy (WWE) may need one or more of these AEDs for seizure control but may be unaware of the potential teratogenicity associated with their use. In utero exposure to AEDs increases the risks for both congenital malformations and other teratogenic defects. Given that approximately 50% of pregnancies are unintended, it is likely that women with epilepsy taking these medications could unknowingly put a growing fetus at risk. For women using contraception while taking these medications, many choose combined hormonal contraceptives (CHCs). Drug-drug interactions exist between AEDs and CHCs that may decrease contraceptive efficacy. The aim of this study was to evaluate prescribing patterns for potentially teratogenic AEDs and contraceptive use in WWE of childbearing ability, including those with potential drug-drug interactions. This study also determined the number of WWE of childbearing ability prescribed potentially teratogenic AEDs and documentation of a pregnancy or contraception plan.

METHODS

This was a retrospective, observational study of WWE age 15-44 years, of childbearing ability, prescribed an AED from July 1, 2011 to June 30, 2012, and who had an appointment at the University of Colorado Hospital Outpatient Neurology Clinic (Anschutz Medical Campus).

RESULTS

One hundred fifteen women with an average age of 30.7 years and various types of seizures were evaluated. The majority of patients were prescribed topiramate (34/115, 30%) or carbamazepine (27/115, 23%). Of the women, 30/115 (26%) had a documented contraception method when taking a potentially teratogenic AED. Of these women prescribed contraception, most (18/30, 60%) used an oral combined hormonal contraceptive or progestin-only pill, a majority of which had a potential for a drug-drug interaction with their AEDs (16/18, 89%). Less than 7% of women received counseling on a contraception plan, and 18% of subjects received counseling on a pregnancy plan.

CONCLUSIONS

Most WWE of childbearing ability taking potentially teratogenic AEDs were not using contraception. Those using contraception frequently had a method that has a significant drug-drug interaction which reduces the effectiveness of contraception. Women with epilepsy of childbearing ability prescribed an AED should be using effective contraception or participating in active discussions about pregnancy planning to avoid unplanned pregnancies and possible teratogenic effects of these AEDs. Documentation about pregnancy planning or contraceptive use in WWE of childbearing ability is minimal and should be discussed at least annually. It is critical for providers to discuss with WWE of childbearing ability the benefits and risks of various AED treatments; the need to select appropriate, effective contraception when pregnancy is not desired; and the importance of counseling regarding contraceptive or pregnancy planning.

Update on diagnosis and management of childhood epilepsies

OBJECTIVES

To review the current evidence base for the diagnosis and management of the childhood epilepsies and to draw attention to the current gaps in this evidence base. The focus will be on therapeutic aspects. Current International League Against Epilepsy (ILAE) terminology will be described and used throughout the discussion. The review will draw attention to recent advances that have been made in both our understanding and treatment of the childhood epilepsies. Potential future directions for research and treatment options will be discussed.

SOURCES

Original articles relevant to the subject were obtained from the MedLine database using pertinent MeSH terms. Relevant papers were read and assimilated. Citation searching was used.

SUMMARY OF THE FINDINGS

Epilepsy is a major cause of global disease burden. Childhood epilepsies are a heterogeneous group of conditions. A multi-axial diagnostic approach should be taken prior to making treatment and management decisions for any individual patient. For the majority of patients, successful control of seizures can be achieved with a single medication. However, a significant minority develops refractory disease. Epilepsy surgery can provide cure for a carefully selected group of these cases.

CONCLUSIONS

There remain significant gaps the evidence base for treatment in several areas of childhood epilepsy. Concerted multi-center efforts should be made to try to close these gaps. A personalized medicine approach may help to reduce the proportion of refractory cases of childhood epilepsy in future.

Autism-Like Behavior and Epigenetic Changes Associated with Autism as Consequences of In Utero Exposure to Environmental Pollutants in a Mouse Model

We tested the hypothesis that in utero exposure to heavy metals increases autism-like behavioral phenotypes in adult animals and induces epigenetic changes in genes that have roles in the etiology of autism. Mouse dams were treated with cadmium, lead, arsenate, manganese, and mercury via drinking water from gestational days (E) 1–10. Valproic acid (VPA) injected intraperitoneally once on (E) 8.5 served as a positive control. Young male offspring were tested for behavioral deficits using four standardized behavioral assays. In this study, in utero exposure to heavy metals resulted in multiple behavioral abnormalities that persisted into adulthood. VPA and manganese induced changes in perseverative/impulsive behavior and social dominance behavior, arsenic caused changes only in perseverative/impulsive behavior, and lead induced abnormalities in social interaction in comparison to the control animals. Brain samples from Mn, Pb, and VPA treated and control animals were evaluated for changes in CpG island methylation in promoter regions and associated changes in gene expression. The Chd7 gene, essential for neural crest cell migration and patterning, was found to be hypomethylated in each experimental animal tested compared to water-treated controls. Furthermore, distinct patterns of CpG island methylation yielded novel candidate genes for further investigation.

The pharmacist's role in promoting preconception health

OBJECTIVE

To review the pharmacist's role in preconception health.

DATA SOURCES

PubMed search using the terms preconception, immunizations, epilepsy, diabetes, depression, tobacco, asthma, hypertension, anticoagulation, pharmacist, pregnancy, and current national guidelines.

DATA SYNTHESIS

Preconception health has become recognized as an important public health focus to improve pregnancy outcomes. Pharmacists have a unique role as accessible health care providers to optimize preconception health by screening women for tobacco use, appropriate immunizations, and current medication use. Counseling patients on preconception risk factors and adequate folic acid supplementation as well as providing recommendations for safe and effective management of chronic conditions are also critical and within the scope of practice for pharmacists.

CONCLUSION

Pharmacists play an important role in medication screening, chronic disease state management, and preconception planning to aid women in preparing for healthy pregnancies.

Neural tube defects

Neural tube defects (NTDs), including spina bifida and anencephaly, are severe birth defects of the central nervous system that originate during embryonic development when the neural tube fails to close completely. Human NTDs are multifactorial, with contributions from both genetic and environmental factors. The genetic basis is not yet well understood, but several nongenetic risk factors have been identified as have possibilities for prevention by maternal folic acid supplementation. Mechanisms underlying neural tube closure and NTDs may be informed by experimental models, which have revealed numerous genes whose abnormal function causes NTDs and have provided details of critical cellular and morphological events whose regulation is essential for closure. Such models also provide an opportunity to investigate potential risk factors and to develop novel preventive therapies.

Oxcarbazepine-loaded polymeric nanoparticles: development and permeability studies across in vitro models of the blood-brain barrier and human placental trophoblast

Encapsulation of antiepileptic drugs (AEDs) into nanoparticles may offer promise for treating pregnant women with epilepsy by improving brain delivery and limiting the transplacental permeability of AEDs to avoid fetal exposure and its consequent undesirable adverse effects. Oxcarbazepine-loaded nanoparticles were prepared by a modified solvent displacement method from biocompatible polymers (poly(lactic-co-glycolic acid) [PLGA] with or without surfactant and PEGylated PLGA [Resomer^® RGPd5055]). The physical properties of the developed nanoparticles were determined with subsequent evaluation of their permeability across in vitro models of the blood–brain barrier (hCMEC/D3 cells) and human placental trophoblast cells (BeWo b30 cells). Oxcarbazepine-loaded nanoparticles with encapsulation efficiency above 69% were prepared with sizes ranging from 140–170 nm, polydispersity indices below 0.3, and zeta potential values below -34 mV. Differential scanning calorimetry and X-ray diffraction studies confirmed the amorphous state of the nanoencapsulated drug. The apparent permeability (P_e) values of the free and nanoencapsulated oxcarbazepine were comparable across both cell types, likely due to rapid drug release kinetics. Transport studies using fluorescently-labeled nanoparticles (loaded with coumarin-6) demonstrated increased permeability of surfactant-coated nanoparticles. Future developments in enzyme-prodrug therapy and targeted delivery are expected to provide improved options for pregnant patients with epilepsy.

Management of epilepsy during pregnancy: evidence-based strategies

Child-bearing years are often the most precarious management period in the life of a woman with epilepsy. This article reviews the results of many different studies with findings that enable the healthcare team to make confident decisions and recommendations during these critical periods. Preconceptional planning, effective contraception and folic acid supplementation are important fundamentals in preparation for pregnancy. There is growing evidence to avoid valproic acid use during the child-bearing years. Emerging data on congenital malformations and neurocognitive outcomes are available for some of the second-generation antiepileptic drugs and appear reassuring for lamotrigine and levetiracetam. Also reviewed are the benefits of postpartum drug tapers and favorable breastfeeding facts. Counseling the mother and her family on medication choices enables the healthcare team to implement informed decisions that are beneficial for the mother and child.

Curcumin affords protection against valproic acid induced teratogenicity by curtailing oxidative stress and inhibiting CYP2C9 activity

The toxic metabolite (E)-2,4-diene-VPA is involved in generation of oxidative stress subsequently contributing in induction of malformations and anomalies and that curcumin affords dose dependent amelioration of the anomalies exerted by VPA.

Basic obstetric pharmacology

Pregnancy is associated with a variety of physiological changes that can alter the pharmacokinetics and pharmacodynamics of several drugs. However, limited data exists on the pharmacokinetics and pharmacodynamics of the majority of the medications used in pregnancy. In this article, we first describe basic concepts (drug absorption, bioavailability, distribution, metabolism, elimination, and transport) in pharmacokinetics. Then, we discuss several physiological changes that occur during pregnancy that theoretically affect absorption, distribution, metabolism, and elimination. Further, we provide a brief review of the literature on the clinical pharmacokinetic studies performed in pregnant women in recent years. In general, pregnancy increases the clearance of several drugs and correspondingly decreases drug exposure during pregnancy. Based on current drug exposure measurements during pregnancy, alterations in the dose or dosing regimen of certain drugs are essential during pregnancy. More pharmacological studies in pregnant women are needed to optimize drug therapy in pregnancy.

[Antiepileptics in women of childbearing age and during pregnancy: comparison of specialized information with the current state of knowledge in Germany and Switzerland]

BACKGROUND

Healthcare professionals regularly read the summary of product characteristics (SmPC) as one of the various sources of information on the risks of drug use in women of childbearing age and during pregnancy. The aim of this article is to present an overview of the teratogenic potential of various antiepileptic drugs and to compare these data with the information provided by the SmPCs.

METHODS

A literature search on the teratogenic risks of 19 antiepileptic agents was conducted and the results were compared with the information on the use in women of childbearing age and during pregnancy provided by the SmPCs of 38 commercial products available in Switzerland and Germany.

RESULTS

The teratogenic risk is discussed in all available SmPCs. Quantification of the risk for birth defects and the numbers of documented pregnancies are mostly missing. Reproductive safety information in SmPCs showed poor concordance with risk levels reported in the literature. Recommendations concerning the need to monitor plasma levels and possibly perform dose adjustments during pregnancy to prevent treatment failure were missing in five Swiss and two German SmPCs.

DISCUSSION

The information regarding use in women of childbearing age and during pregnancy provided by the SmPCs is heterogeneous and poorly reflects the current state of knowledge. Regular updates of SmPCs are warranted in order for these documents to be of reliable use for health care professionals.

Valproic acid suppresses Nrf2/Keap1 dependent antioxidant protection through induction of endoplasmic reticulum stress and Keap1 promoter DNA demethylation in human lens epithelial cells

Recent epidemiological studies confirm the prevalence of cataract in epileptic patients. Similarly, the drugs used to treat epilepsy also show the connection with increased cataract formation. In this present study, we investigated the suppression of Nrf2/Keap1 dependent antioxidant protection through induction of endoplasmic (ER) stress and Keap1 promoter DNA demethylation in human lens epithelial cells (HLECs) treated with valproic acid (VPA), an antiepileptic drug. 20 mM VPA induces ER stress and activates the unfolded protein response (UPR) within 4 h by activating the ER stress sensor proteins, such as PERK, IRE1α, and ATF6 in HLECs. Consequently, the integrated ER stress signals, such as eIF2α, ATF4, BiP, and CHOP are altered accordingly to induce ER-Ca2+ release, reactive oxygen species (ROS) overproduction, and cell death in HLECs treated with VPA. VPA also suppresses the Nrf2, catalase, and glutathione reductase expressions with significant increases in Keap1 protein. Bisulphite genomic DNA sequencing reveals the promoter DNA demethylation in the Keap1 promoter, which results in the overexpression of Keap1 mRNA and protein in HLECs treated with 20 mM VPA. VPA also alters the expression profiles of passive DNA demethylation pathway enzymes such Dnmt1, Dnmt3a, Dnmt3b, and active DNA demethylation pathway enzyme, TET1 leading to DNA demethylation in the Keap1 promoter of HLECs. Overexpressed Keap1 decreases the Nrf2 level, thereby abolishing the Nrf2 dependent antioxidant protection. This might be responsible for lenticular proteins oxidation and cataract formation.

Prenatal exposure to antiepileptic drugs and dental agenesis

OBJECTIVE

The aim of the study was to investigate the association between prenatal exposure to AEDs and the risk of dental agenesis and to differentiate between the possible effects of the different drugs used.

METHODS

Data on 214 exposed and 255 unexposed children, aged 12-18 years, were extracted from the Prescription Database of the Central Denmark Region and North Denmark Region and the Danish Medical Birth Registry. The children's dental charts were examined for the presence of dental agenesis.

RESULTS

Overall, children exposed to AED in utero had an increased risk of developing dental agenesis, but as a group, the difference was not significant (OR = 1.7; [95% CI: 0.8-3.6]). The risk of developing dental agenesis was three-fold increased (OR = 3.1; [95% CI: 1.3-7.4]) in children exposed to valproate in mono- or in poly-therapy with other AEDs than carbamazepine or oxcarbazepine. The risk was further increased (OR = 11.2; [95% CI: 2.4-51.9]) in children exposed to valproate and carbamazepine or oxcarbazepine in combination.

CONCLUSIONS

The present study shows that dental agenesis is a potential congenital abnormality that is related to prenatal exposure to valproate, and dental agenesis may be considered a sensitive marker for the teratogenicity of valproate.

Seizures in pregnancy: epilepsy, eclampsia, and stroke

Seizures during pregnancy complicate <1% of all gestations; however, they are associated with increased adverse maternal and perinatal outcomes (acute and long term). The differential diagnosis of seizures in pregnancy is extensive. Determining the underlying etiology is crucial in the management of these patients. Medical providers caring for pregnant women should be educated about possible etiologies of seizures during pregnancy and the importance of prompt management of these women in a timely fashion. Evaluation and management should be performed in a stepwise fashion and may require a multidisciplinary approach with other specialties such as neurology. The objective of this review is to increase awareness and to provide a stepwise approach toward the diagnosis and management of pregnancies complicated by seizures.

Management of juvenile myoclonic epilepsy

Juvenile myoclonic epilepsy (JME) is a common form of epilepsy and a fairly lifelong disorder that may significantly lower a patient's expectations and potential for a full life. Luckily, it is also a highly treatable disorder, and up to 85% of patients with JME will enjoy satisfactory seizure control. Among anticonvulsants, valproate still stands out as the most efficacious drug, but may be poorly tolerated by some, and is considered unsafe for the fetuses of pregnant women. Alternatives have emerged in recent years, especially levetiracetam, but also topiramate, zonisamide or lamotrigine. In some cases, combination therapy may be useful or even required. One should not forget the potential aggravation induced not only by some commonly used anticonvulsants, especially carbamazepine and oxcarbazepine, but also, in some patients, by lamotrigine. In special settings, older drugs like benzodiazepines and barbiturates may be useful. But the management of JME should also include intervention in lifestyle, with strict avoidance of sleep deprivation and the management of copathologies, including the cognitive and psychiatric problems that are often encountered. With adequate management, there will only remain a small proportion of patients with uncontrolled epilepsy and all of its related problems. Juvenile myoclonic epilepsy is a condition in which the clinician has a fair chance of significantly helping the patient with medication and counseling.

Adverse drug reactions induced by valproic acid

Valproic acid is a widely-used first-generation antiepileptic drug, prescribed predominantly in epilepsy and psychiatric disorders. VPA has good efficacy and pharmacoeconomic profiles, as well as a relatively favorable safety profile. However, adverse drug reactions have been reported in relation with valproic acid use, either as monotherapy or polytherapy with other antiepileptic drugs or antipsychotic drugs. This systematic review discusses valproic acid adverse drug reactions, in terms of hepatotoxicity, mitochondrial toxicity, hyperammonemic encephalopathy, hypersensitivity syndrome reactions, neurological toxicity, metabolic and endocrine adverse events, and teratogenicity.