Pharmacokinetics of Gabapentin during Delivery, in the Neonatal Period, and Lactation: Does a Fetal Accumulation Occur during Pregnancy?

Placental disposition of cannabidiol: An ex vivo perfusion study

OBJECTIVE

In the absence of safety data in humans, the use of cannabidiol (CBD) is not recommended during pregnancy. Yet >50% of pregnancies in women with epilepsy are unintended, making fetal exposure to CBD possible. As a small-molecule, highly lipid-soluble drug, CBD is likely to be distributed into the placenta and cross it. To estimate the placental distribution profile of CBD and its potential short-term placental effects, we conducted an ex vivo perfusion study in human placentas.

METHODS

Placentas were obtained from healthy women undergoing cesarean deliveries. Selected cotyledons were cannulated and perfused for 180 min with a CBD-containing medium (250 ng/mL, .796 μmol·L-1 ; representative of a low therapeutic concentration; n = 8). CBD concentrations were determined at 180 min in the medium and placental tissue using liquid chromatography-tandem mass spectrometry. A customized gene panel array was used to analyze the expression of selected genes in the perfused placental cotyledons as well as in placentas perfused with 1000 ng/mL CBD (3.18 μmol·L-1 ; high therapeutic concentration; n = 8) and in those exposed to the vehicle.

RESULTS

CBD was sequestered in the placental tissue, exhibiting significant variability across samples (median = 5342 ng/g tissue, range = 1066-9351 ng/g tissue). CBD concentrations in the fetal compartment were one fifth of those measured in the maternal compartment (median = 59 ng/mL, range = 48-72 ng/mL vs. 280 = ng/mL, range = 159-388 ng/mL, respectively; p < .01). Placental gene expression was not significantly altered by CBD.

SIGNIFICANCE

The placenta acts as a depot compartment for CBD, slowing down its distribution to the fetus. This phenomenon might yield flatter but prolonged fetal CBD levels in vivo. The attenuated transplacental CBD transfer does not imply that its use by pregnant women is safe for the fetus. Only pregnancy registries and neurocognitive assessments would establish the risk of being antenatally exposed to CBD.

Transfer of anticonvulsants and lithium into amniotic fluid, umbilical cord blood & breast milk: A systematic review & combined analysis

OBJECTIVE

Data on the ability of anticonvulsants and lithium to enter fetal and newborn circulation has become increasingly available; here we estimated penetration ratios in a series of matrices from combined samples of pregnant/breastfeeding women treated with anticonvulsants or lithium.

METHODS

We conducted a systematic literature search in PubMed/EMBASE for studies with concentrations of anticonvulsants/lithium from maternal blood, amniotic fluid, umbilical cord blood and/or breast milk. Penetration ratios were calculated by dividing the concentrations in amniotic fluid, umbilical cord plasma or breast milk by the maternal concentrations. When data from multiple studies were available, we calculated combined penetration ratios, weighting studies' mean by study size.

RESULTS

Ninety-one eligible studies for brivaracetam, carbamazepine, clonazepam, ethosuximide, gabapentin, lacosamide, lamotrigine, levetiracetam, lithium, oxcarbazepine, perampanel, phenobarbital, phenytoin, pregabalin, primidone, topiramate, valproate, vigabatrin and zonisamide were identified. For amniotic fluid, the highest penetration ratios were estimated for levetiracetam (mean 3.56, range 1.27-5.85, n = 2) and lowest for valproate (mean 0.11, range 0.02-1.02, n = 57). For umbilical cord plasma, oxcarbazepine had the highest ratio (mean 1.59, range 0.11-4.33, n = 12) with clonazepam having the lowest (mean 0.55, range 0.52-0.59, n = 2). For breast milk, the highest ratios were observed for oxcarbazepine (mean 3.75, range 0.5-7.0, n = 2), whereas the lowest were observed for valproate (mean 0.04, range 0.01-0.22, n = 121).

DISCUSSION

We observed substantial variability between anticonvulsants and lithium regarding their ability to enter fetal/newborn circulation. Assessing concentrations of anticonvulsants and lithium in maternal samples can provide a surrogate of fetal/infant exposure, although patterns of concentration-dependent effects for maternal/neonatal safety are lacking.

Targeting adverse effects of antiseizure medication on offspring: current evidence and new strategies for safety

INTRODUCTION

For women with epilepsy of reproductive age, antiseizure medications (ASMs) are associated with an increased risk of offspring malformations. There are safety concerns for most anti-seizure medications in the perinatal period, and there is a clear need to identify safe medications. ASMs must transport through biological barriers to exert toxic effects on the fetus, and transporters play essential roles in trans-barrier drug transport. Therefore, it is vital to understand the distribution and properties of ASM-related transporters in biological barriers.

AREAS COVERED

This study reviews the structure, transporter distribution, and properties of the blood-brain, placental, and blood-milk barrier, and summarizes the existing evidence for the trans-barrier transport mechanism of ASMs and standard experimental models of biological barriers.

EXPERT OPINION

Ideal ASMs in the perinatal period should have the following characteristics: 1) Increased transport through the blood-brain barrier, and 2) Reduced transport of the placental and blood-milk barriers. Thus, only low-dose or almost no antiseizure medication could enter the fetus's body, which could decrease medication-induced fetal abnormalities. Based on the stimulated structure and molecular docking, we propose a development strategy for new ASMs targeting transporters of biological barriers to improve the perinatal treatment of female patients with epilepsy.

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.

Management of anti-seizure medications in lactating women with epilepsy

Epilepsy is a common neurological disease. At present, there are about 70 million epilepsy patients in the world, half of them are women, and 30-40% of women with epilepsy are of childbearing potential. Patients with epilepsy who are of childbearing potential face more challenges, such as seizures caused by hormonal fluctuations and the risk of adverse effects on the mother and baby from taking anti-seizure medications (ASMs). Breast milk is one of the best gifts that a mother can give her baby, and breastfeeding can bring more benefits to the baby. Compared with healthy people, people with epilepsy have more concerns about breastfeeding because they are worried that ASMs in their milk will affect the growth and development of the baby, and they are always faced with the dilemma of whether to breastfeed after childbirth. Regarding, whether women with epilepsy can breastfeed while taking ASMs, and whether breastfeeding will adversely affect the baby is still an important topic of concern for patients and doctors. This article reviews the existing research on breastfeeding-related issues in women with epilepsy to guide clinical practice, and improve the breastfeeding compliance of women with epilepsy.

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.

Uptake of antiepileptic drugs in forskolin-induced differentiated BeWo cells: Alteration of gabapentin transport

Previous studies have indicated that the expression levels of several transporters are altered during placental trophoblast differentiation. However, changes in the transport activities of therapeutic agents during differentiation must be comprehensively characterised. Antiepileptic drugs, including gabapentin (GBP), lamotrigine (LTG), topiramate, and levetiracetam, are increasingly prescribed during pregnancy. The objective of this study was to elucidate differences in the uptake of antiepileptic drugs during the differentiation process.Human placental choriocarcinoma BeWo cells were used as trophoblast models. For differentiation into syncytiotrophoblast-like cells, cells were treated with forskolin.The uptake of GBP and LTG was lower in differentiated BeWo cells than in undifferentiated cells. In particular, the maximum uptake rate of GBP transport was decreased in differentiated BeWo cells. Furthermore, GBP transport was trans-stimulated by the amino acids His and Met. We investigated the profiles of amino acids in undifferentiated and differentiated BeWo cells. Supplementation with His and Met, which demonstrated trans-stimulatory effects on GBP uptake, restored GBP uptake in differentiated cells. The findings of this study suggest that drug transport in BeWo cells can be altered before and after differentiation, and that the altered GBP uptake could be mediated by the intracellular amino acid status.

Concentrations of antiseizure medications in breast milk of lactating women with epilepsy: A systematic review with qualitative synthesis

BACKGROUND

Recent position papers and guidelines encourage women with epilepsy (WWE) to exclusively breastfeed their infants because the benefits to their infants outweigh the potential adverse effects caused by exposure to antiseizure medications (ASMs).

OBJECTIVE

The objectives of this review were: to evaluate concentrations of ASMs in breastmilk of lactating WWE, qualitatively synthesize evidence that can be used to estimate theoretical doses as estimated daily intake (EDI) and relative infant dose (RID) of ASMs, and to evaluate potential risks to infants as a result of exposure to ASMs from breastmilk.

METHODS

This systematic review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) as CRD42020223645. The databases: MEDLINE/PubMed, EMBASE, CINAHL/EBSCO, COCHRANE, SpringerLink, ScienceDirect, Summon, WHO International Clinical Trials Registry Platform, and SCOPUS were systematically searched. A qualitative synthesis was adopted in this study.

RESULTS

A total of 15 records were included in this systematic review. The included studies reported levels of 8 ASMs in the breastmilk of WWE. The highest RIDs of carbamazepine, lamotrigine, primidone, phenobarbital, gabapentin, valproic acid, ethosuximide, levetiracetam, and topiramate were 3.70%, 36.33%, 4.96%, 3.15%, 4.37%, 1.90%, 31.49%, 12.50%, and 12.18%, respectively. Breastfeeding might be limited or even discontinued when signs of excessive sedation/drowsiness and/or poor weight gain are evident on infants exposed to primidone and phenobarbital, ethosuximide/primidone, or ethosuximide/phenobarbital.

CONCLUSIONS

Concentrations of ASMs can be detected in breastmilk of WWE and plasma/serum of infants exposed via breastmilk. Healthcare providers and WWE might use the findings of this study to make informed decisions on the safety of breastfeeding while taking ASMs.

Sleep Disturbance in Pregnancy

Sleep is vital to life, even when women enter into pregnancy state. Good sleep is important for a healthy pregnancy. Sleep disturbances are common during pregnancy and can be due to the change of pregnancy itself or the results of sleep disorders. There is growing evidence linking sleep disturbances with adverse maternal and fetal outcomes. Differentiation of sleep disorders in order to provide appropriate treatment as well as promoting good sleep for pregnant women is important. A multidisciplinary team to provide sleep care during antenatal period may be needed.

Alterations in Excitatory and Inhibitory Synaptic Development Within the Mesolimbic Dopamine Pathway in a Mouse Model of Prenatal Drug Exposure

The rise in rates of opioid abuse in recent years in the United States has led to a dramatic increase in the incidence of neonatal abstinence syndrome (NAS). Despite improved understanding of NAS and its acute symptoms, there remains a paucity of information regarding the long-term effects of prenatal exposure to drugs of abuse on neurological development. The primary goal of this study was to investigate the effects of prenatal drug exposure on synaptic connectivity within brain regions associated with the mesolimbic dopamine pathway, the primary reward pathway associated with drug abuse and addiction, in a mouse model. Our secondary goal was to examine the role of the Ca+2 channel subunit α2δ-1, known to be involved in key developmental synaptogenic pathways, in mediating these effects. Pregnant mouse dams were treated orally with either the opioid drug buprenorphine (commonly used in medication-assisted treatment for substance use patients), gabapentin (neuropathic pain drug that binds to α2δ-1 and has been increasingly co-abused with opioids), a combination of both drugs, or vehicle daily from gestational day 6 until postnatal day 11. Confocal fluorescence immunohistochemistry (IHC) imaging of the brains of the resulting wild-type (WT) pups at postnatal day 21 revealed a number of significant alterations in excitatory and inhibitory synaptic populations within the anterior cingulate cortex (ACC), nucleus accumbens (NAC), and medial prefrontal cortex (PFC), particularly in the buprenorphine or combinatorial buprenorphine/gabapentin groups. Furthermore, we observed several drug- and region-specific differences in synaptic connectivity between WT and α2δ-1 haploinsufficient mice, indicating that critical α2δ-1-associated synaptogenic pathways are disrupted with early life drug exposure.

Management of Restless Legs Syndrome in Pregnancy and Lactation

Restless legs syndrome (RLS) affects about 20% of all pregnant women. RLS symptoms are usually moderate to severe in intensity during pregnancy and can result in insomnia, depression, and other adverse outcomes. Although iron deficiency has been implicated as a potential etiological factor, other mechanisms can also play a role. Nonpharmacologic methods are the primary recommended form of treatment for RLS in pregnancy and lactation. Iron supplementation may be considered when the serum ferritin is low; however, several patients are unable to tolerate iron or have severe symptoms despite oral iron replacement. Here, we describe a case of severe RLS in pregnancy and illustrate the dilemmas in diagnosis and management. We review the literature on the prevalence, diagnosis, course, possible underlying pathophysiologic mechanisms and complications of RLS in pregnancy. We describe current best evidence on the efficacy, and safety of nonpharmacologic therapies, oral and intravenous iron supplementation, as well as other medication treatments for RLS in pregnancy and lactation. We highlight gaps in the literature and provide a practical guide for the clinical management of RLS in pregnancy and during breastfeeding.

Effects of antiseizure medications on placental cells: Focus on heterodimeric placental carriers

OBJECTIVE

Appropriate placental nutrient transfer is essential for optimal fetal development. We have previously shown that antiseizure medications (ASMs) can alter the expression of placental carriers for folate and thyroid hormones. Here we extended our analysis to heterodimeric carriers that mediate the placental uptake of amino acids and antioxidant precursors. We focused on the L-type amino acid transporter (LAT)2/SLC7A8, the cystine/glutamate antiporter xCT/SLC7A11, and their chaperone 4F2hc/SLC3A2.

METHODS

BeWo cells were exposed for two or five days to therapeutic concentrations of valproate, levetiracetam, carbamazepine, lamotrigine, or lacosamide. Transcript levels were measured by quantitative PCR. Levetiracetam effects on placental carriers were further explored using a tailored gene array.

RESULTS

At five days, 30 μg/mL levetiracetam (high therapeutic concentrations) significantly reduced the expression of all studied genes (p < 0.05). Carbamazepine treatment was associated with lower SLC7A8 (LAT2) expression (p < 0.05), whereas valproate increased the transcript levels of this transporter by up to 2.0-fold (p < 0.01). Some of these effects were already observed after two incubation days. Lamotrigine did not alter gene expression, and lacosamide slightly elevated SLC3A2 levels (p < 0.05). The array analysis confirmed the trends observed for levetiracetam and identified additional affected genes.

SIGNIFICANCE

Altered expression of placental heterodimeric transporters may represent a mechanism by which ASM affect fetal development. The placental effects are differential, with valproate, carbamazepine and levetiracetam as the more active compounds. The concentration-dependence of those ASM effects are in line with established dose-dependent teratogenicity implying that ASM doses should be adjusted during pregnancy with caution.

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.

[Transfer Mechanisms of Compounds between Mother and Fetus/Infant Aimed for Optimized Medication during Pregnancy and Breastfeeding]

Potential risks to the fetus or infant should be considered prior to medication during pregnancy and lactation. It is essential to evaluate the exposure levels of drugs and their related factors in addition to toxicological effects. Epilepsy is one of the most common neurological complications in pregnancy; some women continue to use antiepileptic drugs (AEDs) to control seizures. Benzodiazepines (BZDs) are widely prescribed for several women who experience symptoms such as anxiety and insomnia during the postpartum period. In this review, we describe the 1) transport mechanisms of AEDs across the placenta and the effects of these drugs on placental transporters, and 2) the transfer of BZDs into breast milk. Our findings indicated that carrier systems were involved in the uptake of gabapentin (GBP) and lamotrigine (LTG) in placental trophoblast cell lines. SLC7A5 was the main contributor to GBP transport in placental cells. LTG was transported by a carrier that was sensitive to chloroquine, imipramine, quinidine, and verapamil. Short-term exposure to 16 AEDs had no effect on folic acid uptake in placental cells. However, long-term exposure to valproic acid (VPA) affected the expression of folate carriers (FOLR1, SLC46A1). Furthermore, VPA administration changed the expression levels of various transporters in rat placenta, suggesting that sensitivity to VPA differed across gestational stages. Lastly, we developed a method for quantifying eight BZDs in human breast milk and plasma using LC/MS/MS, and successfully applied it to quantify alprazolam in breast milk and plasma donated by a lactating woman.

Epilepsy

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

Gabapentin Use for Hospitalized Neonates

BACKGROUND

Despite some clinician advocacy for the use of gabapentin to treat neonatal irritability of presumed neurological origin, the extent of gabapentin administration to hospitalized neonates is unknown. We aimed to identify trends in gabapentin utilization among infants hospitalized in neonatal intensive care units (NICUs) across the United States and to evaluate the associations between clinical diagnoses and gabapentin treatment.

METHODS

We analyzed neonates admitted to the NICU using the Pediatric Health Information System (2005 to 2016) to measure treatment timing, duration, and frequency. We used modified Poisson regression with a robust between-cluster variance estimator to calculate a probability (adjusted relative risk) for gabapentin administration.

RESULTS

Of 278,403 neonates, 374 were administered gabapentin (0.13%). The median treatment duration was 16 days (25th to 75th percentile: 8; 40). Gabapentin use increased from 0% in 2005 to 0.39% in 2016. Treatment was prescribed to neonates at 31 of 48 studied hospitals; 73% of total treated infants localized to five neonatal intensive care units. Term (0.16%) and ≤28 weeks' gestation preterm infants (0.22%) were most likely to receive gabapentin. Varying by gestational age, a diagnosis of chromosomal abnormalities, severe bronchopulmonary dysplasia, hemorrhagic stroke, and neonatal abstinence syndrome were associated with higher treatment with gabapentin. The majority (88.8%) of treated infants did not have a seizure diagnosis.

CONCLUSION

Gabapentin use in NICU in the United States increased in recent years and varies markedly between institutions. Term infants, ≤28 weeks' gestation preterm infants, and neonates with chronic genetic, neurological, and gastrointestinal diagnoses were more likely to receive gabapentin.

Persistent pain after cesarean delivery

The incidence of persistent pain after cesarean deliveries (CD) varies but is much lower than after comparable surgeries. However, with over four million deliveries annually and a rising CD rate, even a low prevalence of persistent pain after CD impacts many otherwise healthy young women. Consideration of the pathophysiology of persistent pain after surgery and the risk factors predisposing women to persistent and chronic pain after CD provides insights into the prevention and treatment of persistent pain; and improves the quality of care and recovery after CD. The findings that the peripartum state and oxytocin confer protection against persistent pain may provide new and interesting perspectives for the prevention and treatment of chronic pain caused by trauma or surgery. Predictive tools available to identify and target patients at high risk of acute and chronic pain have mostly weak to modest predictive correlations and many are either not clinically feasible or too time-consuming to apply. Persistent pain has been linked to the severity of acute postoperative pain and opioid exposure. Modified surgical techniques, neuraxial anesthesia and opioid-sparing analgesia may help limit the development of persistent and chronic pain. The goal of this narrative review is to examine the incidence of persistent pain after CD; review briefly the underlying pathophysiology of persistent pain and the transition from acute to chronic pain (with particular emphasis on the uniqueness after CD); and to review modifiable risk factors and prevention strategies that identify at-risk patients and allow tailored treatment.

Therapeutic Drug Monitoring of Antiepileptic Drugs in Epilepsy: A 2018 Update

BACKGROUND

Antiepileptic drugs (AEDs) are the mainstay of epilepsy treatment. Since 1989, 18 new AEDs have been licensed for clinical use and there are now 27 licensed AEDs in total for the treatment of patients with epilepsy. Furthermore, several AEDs are also used for the management of other medical conditions, for example, pain and bipolar disorder. This has led to an increasingly widespread application of therapeutic drug monitoring (TDM) of AEDs, making AEDs among the most common medications for which TDM is performed. The aim of this review is to provide an overview of the indications for AED TDM, to provide key information for each individual AED in terms of the drug's prescribing indications, key pharmacokinetic characteristics, associated drug-drug pharmacokinetic interactions, and the value and the intricacies of TDM for each AED. The concept of the reference range is discussed as well as practical issues such as choice of sample types (total versus free concentrations in blood versus saliva) and sample collection and processing.

METHODS

The present review is based on published articles and searches in PubMed and Google Scholar, last searched in March 2018, in addition to references from relevant articles.

RESULTS

In total, 171 relevant references were identified and used to prepare this review.

CONCLUSIONS

TDM provides a pragmatic approach to epilepsy care, in that bespoke dose adjustments are undertaken based on drug concentrations so as to optimize clinical outcome. For the older first-generation AEDs (carbamazepine, ethosuximide, phenobarbital, phenytoin, primidone, and valproic acid), much data have accumulated in this regard. However, this is occurring increasingly for the new AEDs (brivaracetam, eslicarbazepine acetate, felbamate, gabapentin, lacosamide, lamotrigine, levetiracetam, oxcarbazepine, perampanel, piracetam, pregabalin, rufinamide, stiripentol, sulthiame, tiagabine, topiramate, vigabatrin, and zonisamide).

Management Strategies for Restless Legs Syndrome/Willis-Ekbom Disease During Pregnancy

Restless legs syndrome/Willis-Ekbom disease is a common disorder during pregnancy that may significantly impact on the health of affected women, leading to negative consequences in the short and long term. An accurate diagnosis helps to recognize the syndrome and choose the optimal therapeutic strategy, based on the characteristics and needs of the patient. This article summarizes the main treatment options recommended by the consensus clinical guidelines of the International Restless Legs Syndrome Study Group and provides a short guide to the management of restless leg syndrome during pregnancy in clinical practice.

Impact of psychiatric medication co-exposure on Neonatal Abstinence Syndrome severity

BACKGROUND

Among opioid-exposed infants, psychiatric medication co-exposure is common. Our objective was to compare Neonatal Abstinence Syndrome (NAS) outcomes based on individual psychiatric medication co-exposures.

METHODS

A retrospective study of 744 opioid-exposed mother-infant dyads from a single institution was performed. Mothers on pharmacotherapy with methadone or buprenorphine at delivery were included. Data were collected on maternal demographics, psychiatric medication use, and NAS outcomes, including any medication treatment, adjunctive medication treatment, length of hospital stay (LOS), and opioid treatment days. The extent to which individual psychiatric medication and polypharmacy exposure were associated with NAS outcomes was assessed using multivariable regression.

RESULTS

Fifty-four percent of the mothers were on ≥1 psychiatric medication, with 32% on ≥2 or psychiatric medications (polypharmacy group). In adjusted models, polypharmacy exposure was associated with longer LOS (β = 4.31 days, 95% CI 2.55-6.06) and opioid treatment days (β = 3.98 days, 95% CI 2.24-5.72) and more treatment with adjunctive medication for NAS (aOR = 2.49, 95% CI 1.57-3.95). Benzodiazepines were associated with longer LOS (β = 4.94, 95% CI 2.86-7.03) and opioid treatment days (β = 4.86, 95% CI 2.61-6.75), and more adjunctive medication treatment (aOR = 2.57, 95% CI 1.49-4.42). Gabapentin was associated with longer LOS (β = 2.79, 95% CI 0.54-5.03), more NAS medication treatment (aOR = 2.96, 95% CI 1.18-7.42) including more adjunctive medications (aOR = 1.92, 95% CI 1.05-3.53).

CONCLUSION

For infants of mothers with OUD who are also on concurrent psychiatric medications, polypharmacy was associated with worse NAS severity. When medically indicated, limiting use of multiple psychiatric medications, particularly benzodiazepines and gabapentin, during pregnancy should be considered to improve NAS outcomes.

[Use of antiepileptic drugs during breastfeeding : What do we tell the mother?]

BACKGROUND

Knowledge about the passage of various antiepileptic drugs into breast milk and its consequences for the infant is limited. Faced with this uncertainty, breastfeeding is often discouraged for these patients. The aim of this study was to comprehensively review the available data regarding antiepileptic drugs during breastfeeding, to compare these data with information provided by the summary of product characteristics (SmPCs), and to provide recommendations for the use of these drugs in breastfeeding women.

MATERIAL AND METHODS

We performed a systematic literature review on breastfeeding data for 23 antiepileptic drugs. A breastfeeding compatibility score was developed and validated. The estimated score based on the literature review was compared with the estimated score based on recommendations provided by the SmPCs.

RESULTS

We identified 75 articles containing exposure and safety data for 15 antiepileptic agents during breastfeeding. The comparison between the score values based on the literature review and on the SmPCs revealed a very low degree of concordance (weighted kappa: 0.08).

CONCLUSION

Phenobarbital, primidone, carbamazepine, valproate and levetiracetam are probably compatible with breastfeeding. Treatment with phenytoin, ethosuximide, clonazepam, oxcarbazepine, vigabatrin, topiramate, gabapentin, pregabalin, lamotrigine and zonisamide can be authorized during breastfeeding, provided breastfed infants are carefully monitored for side effects. Since data on the use of mesuximide, clobazam, rufinamide, felbamate, lacosamide, sultiame, perampanel and retigabine are insufficient to adequately assess the risk for breastfed infants, use in breastfeeding women is in principle not recommended and should be carefully evaluated on a case by case basis. In practice, a risk-benefit analysis should be performed for each mother under antiepileptic treatment wishing to breastfeed her child, so that individual risk factors can adequately be taken into account when counseling the patient.

Devic syndrome and pregnancy: A case series

Background

Devic syndrome or neuromyelitis optica is an autoimmune neurological condition characterized by relapsing symptoms of optic neuritis and transverse myelitis. Women with neuromyelitis optica suffer from adverse pregnancy outcomes and high relapse rates during pregnancy and the postpartum period.

Methods

This case series describes 13 pregnancies in four women with neuromyelitis optica managed at a tertiary hospital in Toronto, Canada.

Results

In most cases, neurologic symptoms either worsened or developed for the first time during pregnancy or the postpartum period, and often responded to a combination of steroids, immunosuppressant medications, plasma exchange and intravenous immunoglobulin. The 13 pregnancies resulted in two miscarriages, three preterm and eight term births. One fetus whose mother was on gabapentin, prednisone and spironolactone, had congenital malformations (aplastic lung and fused fingers).

Conclusions

Despite high frequency of relapses in pregnancy and the postpartum period, with multidisciplinary team management, outcomes for women with neuromyelitis optica are encouraging.

An Atypical Withdrawal Syndrome in Neonates Prenatally Exposed to Gabapentin and Opioids

We report a retrospective case series of 19 infants exposed to both opioids and gabapentin prenatally. We describe a unique behavioral phenotype in 15 of these infants and report a treatment strategy.

Neonatal Gabapentin Withdrawal Syndrome

INTRODUCTION

Gabapentin, an anticonvulsant, neuroleptic, and pain medication, is widely used in both adults and children for management of epilepsy, bipolar illness, and neuropathic pain. Gabapentin use has also been recommended for hyperemesis gravidarum and restless leg syndrome in pregnant mothers.

OBJECTIVE

Although gabapentin use is deemed safe during pregnancy, no clinical reports of gabapentin withdrawal syndrome in a neonate have been described.

RESULTS

We present a newborn who showed signs of withdrawal after prolonged in utero exposure to gabapentin.

CLINICAL IMPLICATIONS

Clinicians should be aware of possible withdrawal symptoms from drugs such as gabapentin, administered to mothers during pregnancy. We also encourage the gradual tapering of gabapentin in neonates over weeks to months similar to the adult population.

A Perioperative Course of Gabapentin Does Not Produce a Clinically Meaningful Improvement in Analgesia after Cesarean Delivery: A Randomized Controlled Trial

BACKGROUND

Studies examining the efficacy of a single preoperative dose of gabapentin for analgesia after cesarean delivery (CD) have been inconclusive. The authors hypothesized that a perioperative course of gabapentin would improve analgesia after CD.

METHODS

This single-center, randomized, double-blind, placebo-controlled, parallel-group, superiority trial was designed to determine the analgesic efficacy of a perioperative course of gabapentin when added to a multimodal analgesic regimen. Women scheduled for elective CD during spinal anesthesia were randomized to receive a perioperative oral course of either gabapentin (600 mg preoperatively followed by 200 mg every 8 h for 2 days) or placebo. Postoperative pain was measured at 24 and 48 h, at rest and on movement, on a visual analogue scale (VAS, 0 to 100 mm). The primary outcome was pain on movement at 24 h. Neonatal outcomes, opiate consumption, VAS satisfaction (0 to 100 mm), adverse effects, and persistent pain were also assessed.

RESULTS

Baseline characteristics were similar between groups. There was a statistically significant but small reduction in VAS pain score (mean [95% CI]) on "movement" (40 mm [36 to 45] vs. 47 mm [42 to 51]; difference, -7 mm [-13 to 0]; P = 0.047) at 24 h in the gabapentin (n = 100) compared with control group (n = 97). There was more sedation in the gabapentin group at 24 h (55 vs. 39%, P = 0.026) but greater patient VAS satisfaction (87 vs. 77 mm, P = 0.003).

CONCLUSIONS

A perioperative course of gabapentin produces a clinically insignificant improvement in analgesia after CD and is associated with a higher incidence of sedation.

Management of epilepsy during pregnancy

Over a million women with epilepsy are of childbearing age in the USA and require careful consideration of not only type of antiepileptic drug (AED) but also dosage, in the event of a planned or unplanned pregnancy. Careful selection of AEDs can lower the potential adverse effects of AEDs while maintaining seizure control for the health of not only on the patient, the mother, but also the unborn fetus. The number of treatment options has increased significantly in the last 20 years and remarkable progress has been made in characterizing the risks AEDs pose to pregnant women and fetuses. There are now robust data on teratogenesis, a growing body of data on neonatal/obstetrical outcomes and on neurodevelopmental problems associated with each AED, and some data about seizure control during pregnancy. Based on clinical evidence so far, levetiracetam and lamotrigine have emerged as the safest during pregnancy, although others may also be suitable. Despite being a common belief, not all polytherapy combinations may be detrimental, especially when avoiding valproate and topiramate. Here, we review the available clinical research, highlighting recent findings and provide thoughts for future directions in the field.

Mood stabilizers in pregnancy and lactation

Management of bipolar during pregnancy and postpartum is very challenging. The treating clinicians have to take into account various factors like current mental state, longitudinal history of the patient, past history of relapse while off medication, response to medication, time of pregnancy at which patient presents to the clinician, etc. The choice of drug should depend on the balance between safety and efficacy profile. Whenever patient is on psychotropic medication, close and intensive monitoring should be done. Among the various mood stabilizers, use of lithium during the second and third trimester appears to be safe. Use of valproate during first trimester is associated with major malformation and long-term sequalae in the form of developmental delay, lower intelligence quotient, and higher risk of development of autism spectrum disorder. Similarly use of carbamazepine in first trimester is associated with higher risk of major congenital malformation and its use in first trimester is contraindicated. Data for lamotrigine (LTG) appears to be more favorable than other antiepileptics. During lactation, use of valproate and LTG is reported to be safe. Use of typical and/atypical antipsychotic is a good option during pregnancy in women with bipolar disorder.

Lactation studies of anticonvulsants: a quality review

AIM

The aim of this review was to investigate the quality of the current literature on the transfer of anticonvulsants to breast milk to provide an overview of which anticonvulsants are in need of further research.

METHODS

We reviewed the quality of the available lactation studies for 19 anticonvulsants against the guidelines of the Food and Drug Administration (FDA) and the International Lactation Consultant Association (ILCA).

RESULTS

Except for one study on lamotrigine and one case report on gabapentin, no study on anticonvulsants had both the absolute infant dose (AID) and milk to plasma ratio (M : P) correctly assessed. Only one study on carbamazepine, phenytoin and vigabatrin was found that correctly assessed the AID. The main cause for this low number is the lack of essential details in published studies, since 25 of 62 studies were case reports, letters or abstracts. Other major shortcomings were the lack of information on sampling methods, the number of samples in a particular dose interval as well as the low number of study participants.

CONCLUSION

The quality of the current literature on the transfer of anticonvulsants to breast milk is low, except for lamotrigine, which makes it hard to draw conclusions about the safety of the use of anticonvulsants during the lactation period. Therefore, further research is needed.

Consensus clinical practice guidelines for the diagnosis and treatment of restless legs syndrome/Willis-Ekbom disease during pregnancy and lactation

Restless legs syndrome (RLS)/Willis-Ekbom disease (WED) is common during pregnancy, affecting approximately one in five pregnant women in Western countries. Many report moderate or severe symptoms and negative impact on sleep. There is very little information in the medical literature for practitioners on the management of this condition during pregnancy. Accordingly, a task force was chosen by the International RLS Study Group (IRLSSG) to develop guidelines for the diagnosis and treatment of RLS/WED during pregnancy and lactation. A committee of nine experts in RLS/WED and/or obstetrics developed a set of 12 consensus questions, conducted a literature search, and extensively discussed potential guidelines. Recommendations were approved by the IRLSSG executive committee, reviewed by IRLSSG membership, and approved by the WED Foundation Medical Advisory Board. These guidelines address diagnosis, differential diagnosis, clinical course, and severity assessment of RLS/WED during pregnancy and lactation. Nonpharmacologic approaches, including reassurance, exercise and avoidance of exacerbating factors, are outlined. A rationale for iron supplementation is presented. Medications for RLS/WED are risk/benefit rated for use during pregnancy and lactation. A few are rated "may be considered" when RLS/WED is refractory to more conservative approaches. An algorithm summarizes the recommendations. These guidelines are intended to improve clinical practice and promote further research.

Does preoperative gabapentin affects the characteristics of post-dural puncture headache in parturients undergoing cesarean section with spinal anesthesia?

Background:

Gabapentin is effective for treating different types of headache including post-dural puncture headache (PDPH), also used for prophylaxis against migraine. We studied the effect of pre-operative administration of gabapentin on the characteristics of PDPH in parturients undergoing cesarean section (CS) under spinal anesthesia.

Materials and Methods:

Women undergoing elective cesarean section under spinal anesthesia were randomized to receive preoperative gabapentin 600 mg or placebo. Spinal anesthesia was achieved with 12.5 mg hyperbaric bupivacaine plus 25 μg fentanyl. Babies were followed up by Apgar scores, umbilical artery blood gases, breastfeeding difficulties, and need for NICU admission. The mothers were followed up for any side-effects of gabapentin for 24 h. Patients with PDPH were re-admitted and onset and duration of the headache were reported and severity was assessed using a visual analog scale (VAS) for 4 days from diagnosis. Paracetamol with caffeine and diclofenac were given for treatment, and the doses were adjusted according to VAS; also number of doses given for each group was recorded.

Results:

Eighty eight patients were randomized, and 2 were excluded. The incidence of headache and co-existing symptoms were similar in both groups. The onset of headache was significantly delayed in gabapentin group (P < 0.05). Also, severity and duration of headache were significantly less in gabapentin group (P < 0.05). The incidence of sedation was more in gabapentin group 11 (26.19%) versus placebo group 3 (6.81%). Neonatal outcomes were statistically insignificant between both groups.

Conclusion:

Pre-operative administration of gabapentin has no effect on incidence of (PDPH) but delays its onset and reduces its severity and duration in parturients undergoing cesarean section with spinal anesthesia without significant adverse effects on the mother or the baby.

Developmental neurotoxicity and anticonvulsant drugs: a possible link

In utero exposure to antiepileptic drugs (AEDs) may affect neurodevelopment causing postnatal cognitive and behavioral alterations. Phenytoin and phenobarbital may lead to motor and learning dysfunctions in the pre-exposed children. These disorders may reflect the interference of these AEDs with the development of hippocampal and cerebellar neurons, as suggested by animal studies. Exposure to valproic acid may result in inhibition of neural stem cell proliferation and/or immature neuron migration in the cerebral cortex with consequent increased risk of neurodevelopmental impairment, such as autistic spectrum disorders. A central issue in the prevention of AED-mediated developmental effects is the identification of drugs that should be avoided in women of child-bearing potential and during pregnancy. The aim of this review is to explore the possible link between AEDs and neurodevelopmental dysfunctions both in human and in animal studies. The possible mechanisms underlying this association are also discussed.

The efficacy of gabapentin in children of partial seizures and the blood levels

AIM

To evaluate the long-term efficacy of gabapentin (GBP) and usefulness of measurement of the blood level for the observation of patients that have partial seizures.

METHODS

Thirty patients (20 effective cases and 10 ineffective cases) treated with GBP for the localization related epilepsy had their peak blood levels of GBP. The levels were measured seven time points, one, 6, 12, 18, 24, 30, and 36month after the start of medication. The efficacy of GBP was evaluated at one month after the initiation of medication and every year for 3years, based on the R Ratio and the degree of improvement for the paroxysmal strength and length.

RESULTS

GBP levels were higher in the effective cases than the levels in the ineffective cases 6months after and 1year after the initiation of medication (p<0.05). The level 6months after the start in the effective cases was 5.429±2.384μg/ml (mean±SD), and 5.837±3.217μg/ml after 1year. The cases that were effective for 1year maintained approximately the same efficacy for 3years after the initiation of medication, but there was no correlation between the level and the R Ratio, paroxysmal strength and length.

CONCLUSIONS

No precise definition of the therapeutic range was recognized because of no correlation between GBP level and the improvement of clinical manifestations. We recommend the GBP optimal range that is established the range within 3-8μg/ml (mean; 5μg/ml) as therapeutic target without the side effect.

The effect of gabapentin versus intrathecal fentanyl on postoperative pain and morphine consumption in cesarean delivery: a prospective, randomized, double-blind study

PURPOSE

Pain after cesarean delivery is a leading cause of chronic pain and there are many attempts to reduce it without total success. Gabapentin is effective in reducing acute and chronic pain with little experience in parturient. The purpose of this study is to compare the effect of pre-emptive gabapentin with intrathecal fentanyl on reducing postoperative pain and morphine consumption in cesarean surgery.

METHODS

Seventy-eight primiparous women who scheduled for non-emergency cesarean delivery were enrolled in the study and separated into two groups. The control group received 12.5 mg of heavy bupivacaine 0.5 % plus 10 μg of fentanyl intrathecally and the case group received 300 mg of gabapentin orally 2 h before surgery and 12.5 mg of heavy bupivacaine 0.5 % intrathecally. Data collection including blood pressure, heart rate, neonate sedation, Apgar score, visual analogous scale at several hours, at first, need to analgesic postoperatively.

RESULTS

In the fentanyl group, the need for analgesic drug was earlier, total dose of morphine in 24 h and patient satisfaction was higher than the gabapentin group. The mean visual analogous scale at several hours postoperatively in the fentanyl groups was significantly higher than the gabapentin groups (P = 0.001).

CONCLUSION

Preemptive use of gabapentin is a safe and effective way to reduce postoperative pain and morphine consumption in parturients after cesarean surgery.

Clinical pharmacokinetics of new-generation antiepileptic drugs at the extremes of age: an update

Epilepsies occur across the entire age range, and their incidence peaks in the first years of life and in the elderly. Therefore, antiepileptic drugs (AEDs) are commonly used at the extremes of age. Rational prescribing in these age groups requires not only an understanding of the drugs' pharmacodynamic properties, but also careful consideration of potential age-related changes in their pharmacokinetic profile. The present article, which updates a review published in 2006 in this journal, focuses on recent findings on the pharmacokinetics of new-generation AEDs in neonates, infants, children, and the elderly. Significant new information on the pharmacokinetics of new AEDs in the perinatal period has been acquired, particularly for lamotrigine and levetiracetam. As a result of slow maturation of the enzymes involved in glucuronide conjugation, lamotrigine elimination occurs at a particularly slow rate in neonates, and becomes gradually more efficient during the first months of life. In the case of levetiracetam, elimination occurs primarily by renal excretion and is also slow at birth, but drug clearance increases rapidly thereafter and can even double within 1 week. In general, infants older than 2-3 months and children show higher drug clearance (normalized for body weight) than adults. This pattern was confirmed in recent studies that investigated the pediatric pharmacokinetics of several new AEDs, including levetiracetam, rufinamide, stiripentol, and eslicarbazepine acetate. At the other extreme of age, in the elderly, drug clearance is generally reduced compared with younger adults because of less efficient drug-metabolizing activity, decreased renal function, or both. This general pattern, described previously for several AEDs, was confirmed in recent studies on the effect of old age on the clearance of felbamate, levetiracetam, pregabalin, lacosamide, and retigabine. For those drugs which are predominantly eliminated by renal excretion, aging-related pharmacokinetic changes could be predicted by measuring creatinine clearance (CLCR). Overall, most recent findings confirm that age is a major factor influencing the pharmacokinetic profile of AEDs. However, pharmacokinetic variability at any age can be considerable, and the importance of other factors should not be disregarded. These include genetic factors, co-morbidities, and drug interactions, particularly those caused by concomitantly administered AEDs which induce or inhibit drug-metabolizing enzymes.