Drug Information Rounds Levetiracetam Use in Pregnancy

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

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

An in vitro Study on the Contractility of Epileptic Myometrium and Effects of Antiepileptic Agents on Oxytocin-Induced Contractions of Myometrium Isolated from Absence Epileptic WAG/Rij Rats

BACKGROUND/AIMS

The aim of this study was to determine whether spontaneous and stimulated contractile activity of myometrium in epileptic rats is different from healthy ones, and whether antiepileptic drugs (AEDs) have any direct influence on myometrial contractility.

METHODS

Myometrial strips from nonpregnant and pregnant adult epileptic WAG/Rij and Wistar rats were suspended in organ bath containing physiological salt solution (37°C and pH 7.4, aerated with 95% oxygen-5% CO2), and isometric contractions were recorded. Effects of cumulative concentrations of selected AEDs including phenytoin, levetiracetam, and valproic acid alone and in combination on oxytocin-induced contractions was examined. Contractile parameters assessed included the area under curve, amplitude, and frequency of contractions, evaluated by 10-min periods. Data were analyzed using one-way analysis of variance and Tukey HSD test.

RESULTS

Spontaneous myometrial contractility and responses to oxytocin showed species difference. Compared with that of control Wistar rats, spontaneous contractions of myometrium from nonpregnant epileptic WAG/Rij rats were significantly higher while being significantly lower in pregnant preparations. Upon stimulation with oxytocin, WAG/Rij myometrium showed significantly lower contractile response compared with preparations from healthy control Wistars (p < 0.01). Phenytoin and valproate caused concentration-dependent significant attenuation (p < 0.05) of spontaneous and oxytocin-induced contractions of myometrium from WAG/Rij and Wistar rats, both nonpregnant and pregnant.

CONCLUSION

Myometrial smooth muscle from epileptic rats showed different spontaneous and oxytocin-induced contractility, and AEDs showed contractile modulatory actions, phenytoin being the most and levetiracetam the least effective. Although in vitro, our findings may be of clinical implications with regard to obstetric complications in epileptics and use of AEDs during pregnancy, and warrants further investigations.

Levetiracetam use during pregnancy in women with epilepsy: Preliminary observations from a tertiary care center in Northern India

INTRODUCTION

Data on efficacy and safety of levetiracetam (LEV) during pregnancy is still limited. We analyzed efficacy and safety of LEV during pregnancy in North Indian women with epilepsy (WWE) which is being presented here.

PATIENTS AND METHODS

This retrospective study included 99 WWE (on treatment with a single antiepileptic drug [AED]) who were evaluated in medical-surgical disorder antenatal clinic of the department of obstetrics and gynecology at a tertiary care teaching hospital and referral center in North India. All the obstetric and fetal data as well as data pertaining to epilepsy were noted meticulously.

RESULTS

In this study (n = 99), 35 women received carbamazepine, 28 received LEV, 15 received valproate (VPA), 13 received phenytoin (PHT), three each received oxcarbazepine and lamotrigine, respectively, and two received clobazam. Although the use of VPA was associated with significantly better control of seizures compared to LEV, its use was associated with higher risk of major congenital malformations (13.3%). The incidence of gestational hypertension was lower while incidence of fetal distress was significantly higher in WWE receiving PHT during pregnancy. None of the child born to pregnant women receiving LEV had any congenital malformation.

CONCLUSION

LEV is a first-line AED during pregnancy. Future prospective studies using therapeutic drug monitoring during pregnancy may further help in establishing its role during pregnancy.

A Systematic Appraisal of Neurosurgical Seizure Prophylaxis: Guidance for Critical Care Management

Clinical decisions are often made in the presence of some uncertainty. Health care should be based on a combination of scientific evidence, clinical experience, economics, patient value judgments, and preferences. Seizures are not uncommon following brain injury, surgical trauma, hemorrhage, altered brain metabolism, hypoxia, or ischemic events. The impact of seizures in the immediate aftermath of injury may be a prolonged intensive care stay or compounding of the primary injury. The aim of brain injury management is to limit the consequences of the secondary damage. The original intention of seizure prophylaxis was to limit the incidence of early-onset seizures. However, clinical trials have been equivocal on this point, and there is concern about the adverse effects of antiepileptic drug therapy. This review of the literature raises concerns regarding the arbitrary division of seizures into early onset (7 d) and late onset (8 d and beyond). In many cases it would appear that seizures present within 24 hours of the injury or after 7 days, which would be outside of the scope of current seizure prophylaxis guidance. There also does not appear to be a pathophysiological reason to divide brain injury-related seizures into these timeframes. Therefore, a solution to the conundrum is to reevaluate current practice. Prophylaxis could be offered to those receiving intensive care for the primary brain injury, where the impact of seizure would be detrimental to the management of the brain injury, or other clinical judgments where prophylaxis is prudent. Neurosurgical seizure management can then focus attention on which agent has the best adverse effect profile and the duration of therapy. The evidence seems to support levetiracetam as the most appropriate agent. Although previous reviews have identified an increase cost associated with the use of levetiracetam, current cost comparisons with phenytoin demonstrate a marginal price differential. The aim of this review is to assimilate the applicable literature regarding seizure prophylaxis. The final guidance is a forum upon which further clinical research could evaluate a new seizure prophylaxis paradigm.

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.

The fetal safety of Levetiracetam: a systematic review

OBJECTIVE

To systematically review the available published evidence on the fetal safety of Levetiracetam with focus on birth defects.

RESULTS

Eight studies met the inclusion criteria; five pregnancy registries and one population based cohort study. A total of 27 major congenital malformations were reported among 1213 Levetiracetam monotherapy - exposed pregnant women, yielding an overall major malformation rate of 2.2% (27/1213) [95% confidence interval of 1.53-3.22]. In contrast, Levetiracetam polytherapy was associated with significantly higher malformation rate of 6.3% (34/541) [95% CI of 4.53-8.65] (P<0.001). Additionally 2 studies investigating child neurodevelopment in Levetiracetam - exposed children revealed that the measured achievements were well above those children exposed to valproic acid, and similar to unexposed controls.

CONCLUSIONS

The current evidence suggests that the overall risk of major malformation after first trimester exposure to Levetiracetam is within the population baseline risk of 1-3%, with no apparent adverse effects on long term child development.

The use of central nervous system active drugs during pregnancy

CNS-active drugs are used relatively often during pregnancy. Use during early pregnancy may increase the risk of a congenital malformation; use during the later part of pregnancy may be associated with preterm birth, intrauterine growth disturbances and neonatal morbidity. There is also a possibility that drug exposure can affect brain development with long-term neuropsychological harm as a result. This paper summarizes the literature on such drugs used during pregnancy: opioids, anticonvulsants, drugs used for Parkinson's disease, neuroleptics, sedatives and hypnotics, antidepressants, psychostimulants, and some other CNS-active drugs. In addition to an overview of the literature, data from the Swedish Medical Birth Register (1996-2011) are presented. The exposure data are either based on midwife interviews towards the end of the first trimester or on linkage with a prescribed drug register. An association between malformations and maternal use of anticonvulsants and notably valproic acid is well known from the literature and also demonstrated in the present study. Some other associations between drug exposure and outcome were found.

Therapeutic drug monitoring in pregnancy

Therapeutic drug monitoring (TDM) is commonly recommended to optimize drug dosing regimens of various medications. It has been proposed to guide therapy in pregnant women, in whom physiological changes may lead to altered pharmacokinetics resulting in difficulty in predicting the appropriate drug dosage. Ideally, TDM may play a role in enhancing the effectiveness of treatment while minimizing toxicity of both the mother and fetus. Monitoring of drug levels may also be helpful in assessing adherence to prescribed therapy in selected cases. Limitations exist as therapeutic ranges have only been defined for a limited number of drugs and are based on data obtained in nonpregnant patients. TDM has been suggested for anticonvulsants, antidepressants, and antiretroviral drugs, based on pharmacokinetic studies that have shown reduced drug concentrations. However, there is only relatively limited (and sometimes inconsistent) information regarding the clinical impact of these pharmacokinetic changes during pregnancy and the effect of subsequent dose adjustments. Further studies are required to determine whether implementation of TDM during pregnancy improves outcome and is associated with any benefit beyond that achieved by clinical judgment alone. The cost effectiveness of TDM programs during pregnancy also remains to be examined.

Managing epilepsy during pregnancy: assessing risk and optimizing care

OPINION STATEMENT

Epilepsy is the most common neurologic condition found in pregnancy. As such, all neurologists, internists, and obstetricians should know how to counsel women with epilepsy as they are considering pregnancy. While all of the usual recommendations for women of childbearing potential apply, including preconceptual and ongoing use of folic acid, calcium, and vitamin D, additional consideration must be given to the need for adjustment or change of anticonvulsant therapy. Monotherapy with the lowest dose of medication needed to control seizures should be prescribed prior to conception. Most anticonvulsants have a favorable profile when used in pregnancy; older anticonvulsants such as valproate and carbamazepine should be avoided, as they are associated with higher rates of fetal malformation, and in the case of valproate, with proven cognitive deficits in children exposed to this medication in utero. With use of any anticonvulsant medication, dosing throughout pregnancy will need to be adjusted to maintain an appropriate serum concentration. Dosing of anticonvulsants needs to be decreased after delivery to avoid medication-related toxicity, although sleep deprivation and hormonal fluctuation can increase the risk of seizures in postpartum women. With proper management, the majority of women with epilepsy can have uneventful pregnancies and healthy babies.

Effects of Levetiracetam on neural tube development and closure of the chick embryos in ovo

PURPOSE

Effects of Levetiracetam (LEV) within its therapeutic range at a 50 mg/kg dose for the chick embryo in ovo has been studied in order to demonstrate whether LEV would effect neural tube closure at the macroscopic morphology or LEV administered embryos still encounter neuroglial detrimental effects at the histological level.

METHODS

Embryos were randomly seperated into control (n = 20) and study (n = 20) groups. The eggshell was windowed at specifically 24 h of incubation, and area underlying the membrane was excised to allow injection with 4.5 μl LEV in the study group, while physiologic saline (0.045 ml) were injected in the control group and each egg were re-incubated for 48 h more. Then, histological and immunohistochemical evaluation of the subjects were done.

RESULTS

Macroscopic evaluation revealed immaturity of the placental vessel network in number and width for the study group in comparison to the controls. Defects of migration, decrease in the crista neuralis content, delay of the basal plates structures in the formation of the usual configuration, and delay in the cellular proliferation and the delay of development for the central nervous system were determined in the LEV-exposed group. Immunostaining of S100 proteins in this study has clearly demonstrated increased expression patterns of both neuroglial and neuronal cell populations. Toluidine blue stainings revealed mostly bipolar, differentiating neurons and crista neuralis cells which is concordant with active migration and differentiation.

CONCLUSIONS

LEV found that delay in the closure of the neural tube and microcephalic fetuses disturb further morphological, biochemical, and functional development.

[Specificities of the epileptic women (oral contraceptives, pregnancy)]

The enzyme-inducing antiepileptic drugs such as carbamazepine, phenytoin, barbiturates, oxcarbazepine do not allow oral contraceptives. The pregnancy must be planned. Every patient in childbearing age should be informed by her practitioner. The rule is to optimize the antiepileptic treatment before the pregnancy: less drugs, less dosages. This optimization will depend on the epileptic syndrome and the nature of the treatment. Valproate of sodium should be avoided, if possible, during pregnancy. Preconceptional supplementation by folic acid should be considered. Antiepileptic drugs monitoring is required during pregnancy. Natural delivery with peridural anaesthesiology is mandatory. The breast feeding must be considered individually.

Levetiracetam Extended Release as Adjuvant Therapy for the Control of Partial-onset Seizures

Extended release (XR) formulation of levetiracetam (LEV) is approved by the Food and Drug Administration as an add-on to other antiepileptic drugs (AEDs) for adults with partial onset seizures. This is based on class-I evidence demonstrating significant seizure reduction in once daily dosing. Keppra-XR is marketed with the brand name of Keppra XR since 2008 (UCB Pharma). Its original immediate release (IR) formulation has been in the market since 2000. LEV has a unique molecular structure which is chemically unrelated to existing AEDs. The precise mechanism of action is unknown. Animal studies showed binding to synaptic vesicle protein SV2A, thought to be involved in modulating synaptic neurotransmitter release. LEV-IR is proven effective as adjunctive therapy for partial-onset seizures, primary generalized tonic-clonic seizures and myoclonic seizures. It was shown to be equivalent to carbamazepine as first-line treatment for partial-onset seizures. The extended release formulation added advantages such as better tolerance and increased compliance.

Advances in epilepsy: new perspectives on new-onset epilepsy, comorbidities, and pharmacotherapy

The purpose of this brief article is to review old concepts of the significance of acute symptomatic seizures, the impact of psychiatric comorbidities on the response of pharmacologic and surgical treatments of the seizure disorder, and the importance of factoring comorbid medical comorbidities into the choice of antiepileptic drugs (AEDs). In addition, this article provides an update on the latest data on the teratogenic effects of AEDs and reviews the most relevant results of a recent practice guideline on pregnancy issues in women with epilepsy. The article closes with a review of the latest advances in the therapeutic effects of first- and second-generation AEDs.