Anticonvulsants and breast feeding: a critical review

Breastfeeding recommendations for women taking anti-seizure medications

The literature regarding breastfeeding and effects of anti-seizure medication (ASM) exposure on the breastfed infant has been evolving rapidly over the last decade as new studies advance our understanding of the extent of medication exposure via breastfeeding and the long-term developmental outcomes of breastfed infants. Currently, strong evidence supports the safety of breastfeeding for women with epilepsy (WWE) taking most prescribed ASMs. In this review, we present a comprehensive overview of the data regarding ASM exposure in breastfed infants and neurodevelopmental outcomes in breastfed infants of mothers taking various ASMs. In addition, we present current breastfeeding recommendations and the reported adverse effects of various ASMs to facilitate decision making in the clinical care of WWE.

The Use of Antiepileptic Drugs During Pregnancy and Fetal Outcomes

Epilepsy affects approximately 1 percent of the population and roughly 1 million women of childbearing age. Estimates suggest that 0.3-0.7 percent of pregnancies occur in women with epilepsy. Epilepsy itself increases the risk of congenital malformation and medications add to this risk. Also, approximately one-half of the use of medications for epilepsy are used for other indications, possibly increasing exposure in some women. As controlled trials with these medications are not performed during pregnancy, data has been accumulated primarily through databases and case studies. This review is intended to update the practitioner about the use and concerns of antiepileptic medications in the presnant woman and the potential effects on the fetus and neonate.

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.

Movement disorders in pregnancy

Movement disorders in women during pregnancy are uncommon. Therefore, high quality studies are limited, and guidelines are lacking for the treatment of movement disorders in pregnancy, thus posing a significant therapeutic challenge for the treating physicians. In this chapter, we discuss movement disorders that arise during pregnancy and the preexisting movement disorders during pregnancy. Common conditions encountered in pregnancy include but are not limited to restless legs syndrome, chorea gravidarum, Parkinson disease, essential tremor, and Huntington disease as well as more rare movement disorders (Wilson's disease, dystonia, etc.). This chapter summarizes the published literature on movement disorders and pharmacologic and surgical considerations for neurologists and physicians in other specialties caring for patients who are pregnant or considering pregnancy.

Psychopharmacological Decision Making in Bipolar Disorder During Pregnancy and Lactation: A Case-by-Case Approach to Using Current Evidence

The safety of pharmacotherapy for bipolar disorder during pregnancy and lactation remains a subject of debate and uncertainty. Clinicians must balance concerns about anatomical and behavioral teratogenicity, maternal mental health, exposure to multiple drugs, and heightened risks for peripartum mood episodes. Risk-benefit analyses must consider factors such as illness severity, past pregnancy treatment outcomes, known drug responsivity, psychosocial supports, and key windows during fetal development. Pharmacological decision making usually changes over the course of pregnancy, given developments in maternal physiology and critical relapse risk periods. Among mood stabilizers, given current research, many experts eschew divalproex and carbamazepine, consider lamotrigine relatively benign, and voice strong opinions for or against lithium. Most second-generation antipsychotics are considered relatively safe, apart from possible extrapyramidal and other motor signs of withdrawal after delivery. In this review, the authors analyze the practical questions, current controversies, and available evidence regarding psychotropic drug therapy during pregnancy and lactation in bipolar disorder.

Maternal Carbamazepine Therapy and Unusual Adverse Effects in a Breastfed Infant

BACKGROUND

Usually, no adverse effects are observed in breastfed infants whose mothers are treated with the anti-epileptic carbamazepine. In this article, we described unusual short-term adverse effects observed in a young infant after exposure to carbamazepine during pregnancy and lactation.

CASE REPORT

A 40-day-old female infant, born at term, was admitted to the Pediatric Clinic at University of Sassari, Italy, for recurrent regurgitations and vomiting. She was breastfed since birth and her mother was under chronic carbamazepine therapy. Gastroesophageal reflux was initially suspected; therefore, thickening of feeds and postural therapy were applied without any benefit. Subsequently, high levels of carbamazepine were detected in infant serum and in maternal breast milk. After an unsuccessful attempt to combine breastfeeding with formula feeding, the switch to exclusive formula feeding was made, with subsequent rapid resolution of symptoms and body weight increase.

DISCUSSION AND CONCLUSIONS

The use of carbamazepine is considered compatible with breastfeeding, even if the potential risk of adverse reactions in breastfed infants exists. In this case, the discontinuation of breastfeeding resulted in the complete resolution of symptoms, suggesting a correlation between the observed manifestations in the infant and her exposure to maternal therapy.

Contraception, pregnancy, and peripartum experiences among women with epilepsy in Bhutan

INTRODUCTION

Reports on the reproductive health of women with epilepsy (WWE) in low- and middle-income countries (LMICs) are limited. Bhutan is a lower income country with a high estimated prevalence of epilepsy and no out-of-pocket payment requirements for health visits or medications.

METHODS

We developed a 10-category survey to interview WWE ages 20-59 years in the Kingdom of Bhutan to understand their contraceptive use and peripartum experiences. WWE were recruited from 2016-2017 from an existing epilepsy cohort and their reproductive health data were merged with epilepsy and socioeconomic data obtained from initial clinical evaluations performed between 2014 and 2016.

RESULTS

Of the 134 WWE eligible for the study, 94 were reachable and there was 1 refusal to participate (response rate 99% among reachable WWE; 69% of all WWE in the cohort). Of the 93 WWE (median age 27 years, range 20-52), 50 (54%) reported prior pregnancies. Of the entire cohort, 55 women responded on contraception: 26 (47%) WWE had never used contraception in their lifetime. Of the 29 WWE who had ever used contraception, the most commonly reported form was male condoms (14/29, 48%), followed by depot medroxyprogesterone acetate injections (13/29, 45%), and intrauterine devices (5/29, 17%). Sixty-three percent of WWE recalled receiving information on family planning (31 of 49). Of the 50 WWE with prior pregnancies, 37 of 46 (80%) used folic acid; 6 WWE reported commencing it in the first trimester while 29 WWE began supplementation in the second trimester. Primary school education or higher was associated with folic acid supplementation during pregnancy (26/29 vs. 11/17, p=0.040). Epilepsy affected at least one of the pregnancies in 38 of the cases (76%) with an average of 2.3 pregnancies per woman). There was a total of 86 pregnancies and an average inter-pregnancy interval of 3.5 years. Ninety-five percent of women attended prenatal care (36/38), 22% had at least one miscarriage (8/37), 14% had at least one pre-term delivery (5/36), and 21% had Caesarean sections (8/38). Seventeen of 38 (45%) of WWE had seizures during pregnancy. A majority of WWE (97%, 37 of 38) with a prior pregnancy reported breastfeeding their infant.

CONCLUSIONS

Nearly half of Bhutanese WWE did not use contraception; among those who used it, male condoms were most common but 11% were at risk of potential drug-drug interactions between oral contraception and enzyme-inducing antiepileptic drugs. Bhutanese WWE had a high rate of prenatal visits. Folic acid was prescribed in most pregnant WWE but the majority began supplementation in the second trimester. The number of pregnancies in WWE in Bhutan (2.3 per woman) was comparable to the number of children per women in Bhutan (2.3). Breastfeeding was practiced almost universally. Points of intervention may include pre-conception initiation of folic acid, optimization of dosing of AEDs with contraceptives, guidelines for peripartum seizure treatment, and establishment of a prospective registry for WWE and their offspring.

Medications and Breast-Feeding: A Guide for Pharmacists, Pharmacy Technicians, and other Healthcare Professionals Part III

Objective:

To provide a guide for practicing pharmacists, pharmacy technicians, and other healthcare professionals so that they are able to counsel and advise breast-feeding mothers and fellow healthcare professionals on the safety and use of antiinfectives, vaccines, antiepileptics, benzodiazepines, psychotherapeutic drugs, and radiopharmaceuticals during breast-feeding.

Data Sources:

Primary texts used by the breast-feeding community ( Medications and Mothers' Milk, Drugs in Pregnancy and Lactation, Drugs and Human Lactation) were searched, as well as Micromedex, MEDLINE, PubMed, EMBASE, and EMBASE2 (1984–February 2004).

Study Selection/Data Extraction:

Multiple sources were used wherever available to validate the data, and primary articles were used to verify all tertiary source information. Search terms included breast-feeding, lactation, nursing, and medications, as well as specific drug names.

Data Synthesis:

Concerns regarding medication use during breast-feeding have caused mothers to either discontinue nursing or not take necessary medications. Complete avoidance of medications or cessation of breast-feeding is often unnecessary. Although there are drugs that can be harmful to nursing infants, breast-milk concentrations of most drugs are insufficient to cause any harm.

Conclusions:

Having objective and reliable information on medications enables pharmacists, pharmacy technicians, other healthcare providers, and mothers to make educated decisions regarding drug therapy and breast-feeding.

Induction of the UDP-Glucuronosyltransferase 1A1 during the Perinatal Period Can Cause Neurodevelopmental Toxicity

Anticonvulsants can increase the risk of developing neurotoxicity in infants; however, the underlying mechanism has not been elucidated to date. Thyroxine [3,5,3',5'-l-tetraiodothyronine (T4)] plays crucial roles in the development of the central nervous system. In this study, we hypothesized that induction of UDP-glucuronosyltransferase 1A1 (UGT1A1)-an enzyme involved in the metabolism of T4-by anticonvulsants would reduce serum T4 levels and cause neurodevelopmental toxicity. Exposure of mice to phenytoin during both the prenatal and postnatal periods significantly induced UGT1A1 and decreased serum T4 levels on postnatal day 14. In the phenytoin-treated mice, the mRNA levels of synaptophysin and synapsin I in the hippocampus were lower than those in the control mice. The thickness of the external granule cell layer was greater in phenytoin-treated mice, indicating that induction of UGT1A1 during the perinatal period caused neurodevelopmental disorders. Exposure to phenytoin during only the postnatal period also caused these neurodevelopmental disorders. A T4 replacement attenuated the increase in thickness of the external granule cell layer, indicating that the reduced T4 was specifically associated with the phenytoin-induced neurodevelopmental disorder. In addition, these neurodevelopmental disorders were also found in the carbamazepine- and pregnenolone-16-α-carbonitrile-treated mice. Our study is the first to indicate that UGT1A1 can control neurodevelopment by regulating serum T4 levels.

New antiepileptic drugs: focus on ezogabine, clobazam, and perampanel

Ezogabine, clobazam, and perampanel are among the newest antiseizure drugs approved by the Food and Drug Administration between 2011 and 2012. Ezogabine and perampanel are approved for adjunctive treatment of partial epilepsy. Perampanel is also approved for adjunctive treatment of primary generalized tonic–clonic seizures. Ezogabine and perampanel have novel mechanisms of action. Ezogabine binds to voltage-gated potassium channels and increases the M-current thereby causing membrane hyperpolarization. Perampanel is a selective, non-competitive 2-amino-3-(3-hydroxy-5-methyl-isoxazol-4-yl)propanoic acid receptor antagonist, which reduces neuronal excitation. Clobazam has been used worldwide since the 1970s and is approved for adjunctive treatment of seizures associated with Lennox-Gastaut syndrome. Clobazam is the only 1,5-benzodiazepine currently in clinical use, which is less sedating than the commonly used 1,4-benzodiazepines. Phase III multicenter, randomized, double-blind, placebo-controlled trials demonstrated efficacy and good tolerability of these 3 new antiepileptic drugs. These drugs represent a welcome addition to the armamentarium of practitioners, but it remains to be seen how they will affect the landscape of pharmacoresistant epilepsy.

Breastfeeding and migraine drugs

PURPOSE

Breastfeeding women may suffer from migraine. While we have many drugs for its treatment and prophylaxis, the majority are poorly studied in breastfeeding women. We conducted a review of the most common anti-migraine drugs (AMDs) and we determined their lactation risk.

METHODS

For each AMD, we collected all retrievable data from Hale's Medications and Mother Milk (2012), from the LactMed database (2014) of the National Library of Medicine, and from a MedLine Search of relevant studies published in the last 10 years.

RESULTS

According to our review, AMDs safe during breastfeeding are as follows: low-dose acetylsalicylic acid (ASA), ibuprofen, sumatriptan, metoprolol, propranolol, verapamil, amitriptyline, escitalopram, paroxetine, sertraline, acetaminophen, caffeine, and metoclopramide. AMDs compatible with breastfeeding but warranting caution are as follows: diclofenac, ketoprofen, naproxen, most new triptans, topiramate, valproate, venlafaxine, and cyproheptadine. Finally, high-dose ASA, atenolol, nadolol, cinnarizine, flunarizine, ergotamine, methysergide, and pizotifen are contraindicated.

CONCLUSIONS

According to our review, the majority of the revised AMDs were assessed to be compatible with breastfeeding.

Antiepileptic drugs and breastfeeding

INTRODUCTION

This review provides a synopsis for clinicians on the use of antiepileptic drugs (AEDs) in the breastfeeding mother.

METHODS

For each AED, we collected all retrievable data from Hale's "Medications and Mother Milk" (2012), from the LactMed database (2013) of the National Library of Medicine, and from a MedLine Search of relevant studies in the past 10 years.

RESULTS

Older AEDs, such as carbamazepine, valproic acid, phenytoin, phenobarbital, primidone are considered to have a good level of safety during lactation, due to the long term clinical experience and the consequent amount of available data from the scientific literature. On the contrary, fewer data are available on the use of new AEDs. Therefore, gabapentin, lamotrigine, oxcarbazepine, vigabatrin, tiagabine, pregabalin, leviracetam and topiramate are compatible with breastfeeding with a less documented safety profile. Ethosuximide, zonisamide and the continue use of clonazepam and diazepam are contraindicated during breastfeeding.

CONCLUSIONS

Although the current available advice on the use of AEDs during breastfeeding, given by different accredited sources, present some contradictions, most AEDs can be considered safe according to our review.

Intrapartum single-dose carbamazepine reduces nevirapine levels faster and may decrease resistance after a single dose of nevirapine for perinatal HIV prevention

BACKGROUND

World Health Organization guidelines recommend zidovudine + lamivudine for 7 days from labor onset in HIV-infected women receiving single-dose nevirapine (sdNVP) to cover prolonged subtherapeutic nevirapine concentrations. Although effective, this is complicated and does not eliminate resistance; alternative strategies could add benefit.

METHODS

Antiretroviral-naive HIV-infected pregnant women aged 18-40 years, with CD4 >200 cells per cubic millimeter, able to regularly attend the antenatal clinics in Moshi, Tanzania, were enrolled 1:1 by alternate allocation to receive 200 mg sdNVP alone or in combination with open-label 400-mg single-dose carbamazepine (sdNVP/CBZ) at delivery (ClinicalTrials.gov NCT00294892). The coprimary outcomes were nevirapine plasma concentrations 1 week and nevirapine resistance mutations 6 weeks postpartum. Analyses were based on those still eligible at delivery.

RESULTS

Ninety-seven women were assigned to sdNVP and 95 to sdNVP/CBZ during pregnancy, of whom 75 sdNVP and 83 sdNVP/CBZ were still eligible at delivery at study sites. The median (interquartile range) nevirapine plasma concentration was 1.55 (0.88-1.84) mg/L in sdNVP (n = 61) and 1.40 (0.93-1.97) mg/L in sdNVP/CBZ (n = 72) at delivery (P = 0.91), but 1 week later was significantly lower in sdNVP/CBZ [n = 63; 0.09 (0.05-0.20) mg/L] than in sdNVP [n = 52; 0.20 (0.09-0.31) mg/L; rank-sum: P = 0.004] (geometric mean ratio: 0.64, 95% confidence interval: 0.43 to 0.96; P = 0.03). Six weeks postpartum, nevirapine mutations were observed in 11 of 52 (21%) in sdNVP and 6 of 55 (11%) in sdNVP/CBZ (odds ratio = 0.46, 95% confidence interval: 0.16 to 1.34; P = 0.15).

CONCLUSIONS

Addition of single-dose carbamazepine to sdNVP at labor onset in HIV-infected, pregnant women did not affect nevirapine plasma concentration at delivery, but significantly reduced it 1 week postpartum, with a trend toward fewer nevirapine resistance mutations.

Old and new antiepileptic drugs during pregnancy and lactation--report of a case

We describe a case of a woman with epilepsy treated with primidone/phenobarbital (so-called "old" antiepileptic drug) and levetiracetam (so-called "new" antiepileptic drug) who was discouraged from breastfeeding, resulting in clinically significant withdrawal seizures in her newborn. As a consequence, even when two or more antiepileptic drugs are needed for the treatment of women with epilepsy, breastfeeding should be recommended, mothers should be informed about the possibility of drug effects on the neonate, and infants of mothers treated with primidone/phenobarbital should be closely monitored for possible signs of sedation.

Is breast-feeding of infants advisable for epileptic mothers taking antiepileptic drugs?

Epilepsy is a relatively common maternal complication affecting 0.3-0.5% of pregnant women. For most mothers with epilepsy, the use of antiepileptic drugs (AED) is unavoidable, even during pregnancy and lactation. Therefore, the fetus is indirectly exposed to AED via the placenta and breast milk. AED are also prescribed for female patients with other diseases, such as bipolar disorders. In clinical settings, physicians are frequently questioned whether or not women patients taking AED should breast-feed their offspring. Thus, it is necessary to establish an optimum AED regimen for women taking AED, in particular for those with epilepsy during pregnancy and lactation. In this article, we critically review the effects of AED on infants via breast milk and attempt to provide suggestions for clinicians regarding these effects during breast-feeding, based on the data of transplacental passage of AED, breast milk concentration/maternal serum concentration ratios, AED metabolism in infants and the effects of AED in breast milk on infants.

Pregnancy, epilepsy, and anticonvulsants

The majority of epileptic disorders are not self-limiting over time, and therefore require a long-lasting and often even lifelong antiepileptic drug (AED) treatment, in Wi/omen with epilepsy, the influence of their disease on the possibility and course of pregnancies, as well as the potential impact of the AED treatment on mother and child, are crucial questions.

This review addresses the clinically relevant knovledge concerning the impact of the disease itself and the AED treatment on fertility, pregnancy, delivery, the postpartum period, and teratogenicity. Some of the new AEDs appear to have a favorable profile due to a lack of clinically relevant interactions and promising teratogenic profiles. However, the finding of decreases in lamotrigine serum concentrations during hormonal contraception and pregnancy is an instructive example, shovt/ing that ongoing studies are urgently needed to further investigate stillunanswered questions. Several prospective multinational surveys are currently being performed, and should add essential information in this context.

Transfer of dexamphetamine into breast milk during treatment for attention deficit hyperactivity disorder

AIMS

To investigate dexamphetamine transfer into milk, infant doses and effects in the breast-fed infant.

METHODS

Four women taking dexamphetamine, and their infants were studied.

RESULTS

The median maternal dexamphetamine dose was 18 mg day(-1) (range 15-45 mg day(-1)). Median (interquartile range) descriptors were 3.3 (2.2-4.8) for milk/plasma ratio, 21 microg kg(-1) day(-1) (11-39) for absolute infant dose and 5.7% (4-10.6%) for relative infant dose. No adverse effects were seen. In three infants tested, dexamphetamine in plasma was undetected in one (limit of detection 1 microg l(-1)) and present at 18 microg l(-1) and 2 microg l(-1) in the other two.

CONCLUSION

Dexamphetamine readily transfers into milk. The relative infant dose was <10% and within a range that is generally accepted as being 'safe' in the short term.

Using pharmacokinetics to predict the effects of pregnancy and maternal-infant transfer of drugs during lactation

Knowledge of pharmacokinetics and the use of a mechanistic-based approach can improve our ability to predict the effects of pregnancy for medications when data are limited. Despite the many physiological changes that occur during pregnancy that could theoretically affect absorption, bioavailability does not appear to be altered. Decreased albumin and alpha(1)-acid glycoprotein concentrations during pregnancy will result in decreased protein binding for highly bound drugs. For drugs metabolised by the liver, this can result in misinterpretation of total plasma concentrations of low extraction ratio drugs and overdosing of high extraction ratio drugs administered by non-oral routes. Renal clearance and the activity of the CYP isozymes, CYP3A4, 2D6 and 2C9, and uridine 5'-diphosphate glucuronosyltransferase are increased during pregnancy. In contrast, CYP1A2 and 2C19 activity is decreased. The dose of a drug an infant receives during breastfeeding is dependent on the amount excreted into the breast milk, the daily volume of milk ingested and the average plasma concentration of the mother. The lipophilicity, protein binding and ionisation properties of a drug will determine how much is excreted into the breast milk. The milk to plasma concentration ratio has large inter- and intrasubject variability and is often not known. In contrast, protein binding is usually known. An extensive literature review was done to identify case reports including infant concentrations from breast-fed infants exposed to maternal drugs. For drugs that were at least 85% protein bound, measurable concentrations of drug in the infant did not occur if there was no placental exposure immediately prior to or during delivery. Knowledge of the protein binding properties of a drug can provide a quick and easy tool to estimate exposure of an infant to medication from breastfeeding.

Brief Report: Enzyme Inducers Reduce Elimination Half-Life After a Single Dose of Nevirapine in Healthy Women

OBJECTIVE

Single-dose nevirapine (SD-NVP) to prevent mother-to-child transmission (MTCT) of HIV is associated with development of NVP resistance, probably because of its long half-life in combination with a low genetic barrier to resistance. The objective of this study was to find enzyme inducers to reduce the NVP half-life.

DESIGN

The design of this phase 1 pharmacokinetic study was a single-center, open-label, 2-period, 9-group study.

METHODS

After administration of a single 200-mg dose of NVP to HIV-seronegative nonpregnant women in periods 1 and 2, blood was sampled twice a week for 21 days. In period 2, additional interventions (single-dose carbamazepine, phenobarbital, or phenytoin; phenytoin for 3 or 7 days; or St. John's wort, vitamin A, or cholecalciferol for 14 days) were administered to all subjects except for the control group.

RESULTS

Thirty-six subjects participated. In 3 intervention groups, the T-half ratio (nevirapine half-life in period 2/half-life in period 1) differed significantly from that in the control group: a single 400-mg dose of carbamazepine (P = 0.021) or 184 mg of phenytoin once daily for 3 (P = 0.021) or 7 days (P = 0.021). The median decreases in the NVP half-life were 18.8, 19.0, and 16.9 hours, respectively.

CONCLUSIONS

Interventions with a single dose of 400 mg of carbamazepine or 184 mg of phenytoin for 3 or 7 days effectively reduced the NVP half-life. Appropriately powered safety and feasibility end point studies are warranted before these interventions can be tested in the setting of single-dose NVP for prevention of mother-to-child transmission (PMTCT) of HIV to reduce the development of NVP resistance.

Levetiracetam Concentrations in Serum and in Breast Milk at Birth and during Lactation

PURPOSE

To study the pharmacokinetics of levetiracetam (LEV) at birth, during lactation, and in the nursed infant.

METHODS

Eight consecutive breast-feeding women with epilepsy treated with LEV twice daily and their infants were studied.

RESULTS

The mean umbilical cord serum/maternal serum ratio was 1.14 (range, 0.97-1.45) (n = 4). The mean milk/maternal serum concentration ratio was 1.00 (range, 0.76-1.33) at 3 to 5 days after delivery (n = 7). At sampling 2 weeks to 10 months after delivery (n = 5), it was similar (range, 0.85-1.38). At 3 to 5 days after delivery, the infants had very low LEV serum concentrations (<10-15 microM), a finding that persisted during continued breast-feeding. No malformations were detected, and in none of the infants did signs of adverse effects develop.

CONCLUSIONS

Our data indicate an extensive transfer of LEV from mother to fetus and into breast milk. However, breast-fed infants had very low LEV serum concentrations, suggesting a rapid elimination of LEV.

Clinical pharmacokinetics of oxcarbazepine

Oxcarbazepine is an antiepileptic drug with a chemical structure similar to carbamazepine, but with different metabolism. Oxcarbazepine is rapidly reduced to 10,11-dihydro-10-hydroxy-carbazepine (monohydroxy derivative, MHD), the clinically relevant metabolite of oxcarbazepine. MHD has (S)-(+)- and the (R)-(-)-enantiomer, but the pharmacokinetics of the racemate are usually reported. The bioavailability of the oral formulation of oxcarbazepine is high (>95%). It is rapidly absorbed after oral administration, reaching peak concentrations within about 1-3 hours after a single dose, whereas the peak of MHD occurs within 4-12 hours. At steady state, the peak of MHD occurs about 2-4 hours after drug intake. The plasma protein binding of MHD is about 40%. Cerebrospinal fluid concentrations of MHD are in the same range as unbound plasma concentrations of MHD. Oxcarbazepine can be transferred significantly through the placenta in humans. Oxcarbazepine and MHD exhibit linear pharmaco-kinetics and no autoinduction occurs. Elimination half-lives in healthy volunteers are 1-5 hours for oxcarbazepine and 7-20 hours for MHD. Longer and shorter elimination half-lives have been reported in elderly volunteers and children, respectively. Mild to moderate hepatic impairment does not appear to affect MHD pharmacokinetics. Renal impairment affects the pharmacokinetics of oxcarbazepine and MHD. The interaction potential of oxcarbazepine is relatively low. However, enzyme-inducing antiepileptic drugs such as phenytoin, phenobarbital or carbamazepine can reduce slightly the concentrations of MHD. Verapamil may moderately decrease MHD concentrations, but this effect is probably without clinical relevance. The influence of oxcarbazepine on other antiepileptic drugs is not clinically relevant in most cases. However, oxcarbazepine appears to increase concentrations of phenytoin and to decrease trough concentrations of lamotrigine and topiramate. Oxcarbazepine lowers concentrations of ethinylestra-diol and levonorgestrel, and women treated with oxcarbazepine should consider additional contraceptive measures. Due to the absent or lower enzyme-inducing effect of oxcarbazepine, switching from carbamazepine to oxcarbazepine can result in increased serum concentrations of comedication, sometimes associated with adverse effects. The effect of oxcarbazepine appears to be related to dose and to serum concentrations of MHD. In general, daily fluctuations of MHD concentration are relatively slight, smaller than would be expected from the elimination half-life of MHD. However, relatively high fluctuations can be observed in individual patients. Therapeutic monitoring may help to decide whether adverse effects are dependent on MHD concentrations. A mean therapeutic range of 15-35 mg/L for MHD seems to be appropriate. However, more systematic studies exploring the concentration-effect relationship are required.

[Lamotrigine in women with epilepsy. Review of present data]

The manuscript deals with the tolerability of Lamotrigine in women. The recent literature is reviewed with respect to interactions with oral contraceptives, sexuality, infertility, interactions with sex hormones, polycystic ovarian syndrome, adipositas, cosmetic side effects, osteoporosis, pregnancy, breast feeding, and teratogenetic effects. The available data have practical implications for the safe use of Lamotrigine in women.

Reproductive and metabolic disorders in women with epilepsy

Epilepsy is a common neurologic disorder affecting women during the reproductive years. Seizures and some antiepileptic drugs (AEDs) can compromise reproductive health, and some AEDs can adversely affect carbohydrate and bone metabolism. Women with epilepsy have lower birth rates and more frequent anovulatory menstrual cycles. This appears to be related to seizure- and AED-associated reproductive endocrine disturbances. Carbamazepine (CBZ), phenytoin (PHT), and phenobarbital (PB) induce hepatic cytochrome P450 enzymes and lower endogenous estrogens, adrenal and ovarian androgens, and contraceptive steroids. Valproate (VPA) inhibits steroid hormone metabolism, elevates androgens, and predisposes to phenotypic signs of hyperandrogenism-hirsutism, obesity, acne, and frequent anovulatory cycles. VPA is associated with weight gain, probably by altering insulin metabolism. CBZ, PHT, and VPA, but not lamotrigine (LTG), are associated with lower levels of calcium. PHT, but not VPA or LTG, appears to accelerate bone turnover. AED effects on bone mineral metabolism may explain the elevated risk of fracture described in women with epilepsy. Prospective pregnancy registries are beginning to provide information about AED-associated teratogenesis. The North American Antiepileptic Drug Pregnancy Registry reports a 12% rate of major malformations after first trimester exposure to PB and an 8.6% rate after first trimester exposure to VPA. A prospective LTG-specific registry reports a 1.8% chance of major malformations after the first trimester. The registries will continue to release information as data become significant. In the meantime, practitioners can be alert to signs and symptoms of reproductive or metabolic health disturbances and participate in pregnancy registry efforts.

Treatment of epilepsy in women of reproductive age: pharmacokinetic considerations

Although epilepsy affects men and women equally, there are many women's health issues in epilepsy, especially for women of childbearing age. These issues, which include menstrual cycle influences on seizure activity (catamenial epilepsy), interactions of contraceptives with antiepileptic drugs (AEDs), pharmacokinetic changes during pregnancy, teratogenicity and the safety of breastfeeding, challenge both the woman with epilepsy and the many healthcare providers involved in her care. Although the information in the literature on women's issues in epilepsy has grown steeply in recent years, there are many examples showing that much work is yet to be done. The purpose of this article is to review these issues and describe practical considerations for women of childbearing age with epilepsy. The article addresses the established or "first-generation" AEDs (phenobarbital, phenytoin, primidone, carbamazepine, ethosuximide and valproic acid) and the "second-generation" AEDs (felbamate, gabapentin, lamotrigine, levetiracetam, oxcarbazepine, tiagabine, topiramate, vigabatrin and zonisamide). Although a relationship between hormones and seizure activity is present in many women, good treatment options for catamenial epilepsy remain elusive. Drug interactions between enzyme-inducing AEDs and contraceptives are well documented. Higher dosages of oral contraceptives or a second contraceptive method are suggested if women use an enzyme-inducing AED. Planned pregnancy and counselling before conception is crucial. This counselling should include, but is not limited to, folic acid supplementation, medication adherence, the risk of teratogenicity and the importance of prenatal care. AED dosage adjustments may be necessary during pregnancy and should be based on clinical symptoms, not entirely on serum drug concentrations. Many groups have turned their attention to women's issues in epilepsy and have developed clinical practice guidelines. Although the future holds promise in this area, many questions and the need for progress remain.