Treatment of epilepsy in women of reproductive age: pharmacokinetic considerations

Caring for women with epilepsy in Palestine: A qualitative study of the current status

OBJECTIVE

This qualitative study was conducted to explore the current status of caring for women with epilepsy (WWE) in the Palestinian healthcare system.

METHODS

This study used an explorative qualitative design. A purposive sampling technique was used to recruit the participants. Semi-structured in-depth interviews were conducted with neurologists (n = 6), gynecologists (n = 5), psychiatrists (n = 3), an internist (n = 1), and clinical pharmacists (n = 5). The interpretive description methodology was used to thematically analyze the qualitative data.

RESULTS

A total of 745 min (12.4 h) of interview time were analyzed. The qualitative data collected in this study were categorized under 3 major themes and multiple subthemes. The 3 major themes were: (1) diagnosis and care for patients with epilepsy, (2) general issues in caring for patients with epilepsy, and (3) consideration of women's issues in the pharmacotherapy of epilepsy. Formally adopted protocols/criteria for the diagnosis and care for WWE were lacking.

CONCLUSION

Findings of this qualitative study showed a need to formally adopt uniform guidelines that can guide the diagnosis and care of WWE in the Palestinian healthcare system. The findings of this study might be informative to healthcare providers, decision-makers in healthcare authorities, WWE, and patient advocacy groups who could be interested in improving and benchmarking healthcare services provided to WWE. Future studies are still needed to quantitatively measure adherence to the international guidelines in caring for WWE.

Which information on women's issues in epilepsy does a community pharmacist need to know? A Delphi consensus study

OBJECTIVE

The aim of this study was to develop and achieve consensus on a core list of important knowledge items that community pharmacists should know on women's issues in epilepsy.

METHODS

This was a consensual study using a modified Delphi technique. Knowledge items were collected from the literature and from nine key contacts who were interviewed on their views on what information community pharmacists should have on women's issues in epilepsy. More knowledge items were suggested by five researchers with interest in women's issues who were contacted to rate and comment on the knowledge items collected. Two iterative Delphi rounds were conducted among a panel of pharmacists (n=30) to achieve consensus on the knowledge items to be included in the core list. Ten panelists ranked the knowledge items by their importance using the Analytical Hierarchy Process (AHP).

RESULTS

Consensus was achieved to include 68 knowledge under 13 categories in the final core list. Items ranked by their importance were related to the following: teratogenicity (10.3%), effect of pregnancy on epilepsy (7.4%), preconception counseling (10.3%), bone health (5.9%), catamenial epilepsy (7.4%), menopause and hormonal replacement therapy (2.9%), contraception (14.7%), menstrual disorders and infertility (8.8%), eclampsia (2.9%), breastfeeding (4.4%), folic acid and vitamin K (5.9%), counseling on general issues (14.7%), and sexuality (4.4%).

CONCLUSION

Using consensual knowledge lists might promote congruence in educating and/or training community pharmacists on women's issues in epilepsy. Future studies are needed to investigate if such lists can improve health services provided to women with epilepsy (WWE).

Pregnancy-Associated Changes in Pharmacokinetics: A Systematic Review

BACKGROUND

Women are commonly prescribed a variety of medications during pregnancy. As most organ systems are affected by the substantial anatomical and physiological changes that occur during pregnancy, it is expected that pharmacokinetics (PK) (absorption, distribution, metabolism, and excretion of drugs) would also be affected in ways that may necessitate changes in dosing schedules. The objective of this study was to systematically identify existing clinically relevant evidence on PK changes during pregnancy.

METHODS AND FINDINGS

Systematic searches were conducted in MEDLINE (Ovid), Embase (Ovid), Cochrane Central Register of Controlled Trials (Ovid), and Web of Science (Thomson Reuters), from database inception to August 31, 2015. An update of the search from September 1, 2015, to May 20, 2016, was performed, and relevant data were added to the present review. No language or date restrictions were applied. All publications of clinical PK studies involving a group of pregnant women with a comparison to nonpregnant participants or nonpregnant population data were eligible to be included in this review. A total of 198 studies involving 121 different medications fulfilled the inclusion criteria. In these studies, commonly investigated drug classes included antiretrovirals (54 studies), antiepileptic drugs (27 studies), antibiotics (23 studies), antimalarial drugs (22 studies), and cardiovascular drugs (17 studies). Overall, pregnancy-associated changes in PK parameters were often observed as consistent findings among many studies, particularly enhanced drug elimination and decreased exposure to total drugs (bound and unbound to plasma proteins) at a given dose. However, associated alterations in clinical responses and outcomes, or lack thereof, remain largely unknown.

CONCLUSION

This systematic review of pregnancy-associated PK changes identifies a significant gap between the accumulating knowledge of PK changes in pregnant women and our understanding of their clinical impact for both mother and fetus. It is essential for clinicians to be aware of these unique pregnancy-related changes in PK, and to critically examine their clinical implications.

Pharmacokinetic characteristics of antiepileptic drugs (AEDs)

Antiepileptic drugs (AEDs) are routinely prescribed for the management of a variety of neurologic and psychiatric conditions, including epilepsy and epilepsy syndromes. Physiologic changes due to aging, pregnancy, nutritional status, drug interactions, and diseases (ie, those involving liver and kidney function) can affect pharmacokinetics of AEDs. This review discusses foundational pharmacokinetic characteristics of AEDs currently available in the United States, including clobazam but excluding the other benzodiazepines. Commonalities of pharmacokinetic properties of AEDs are discussed in detail. Important differences among AEDs and clinically relevant pharmacokinetic interactions in absorption, distribution, metabolism, and/or elimination associated with AEDs are highlighted. In general, newer AEDs have more predictable kinetics and lower risks for drug interactions. This is because many are minimally or not bound to serum proteins, are primarily renally cleared or metabolized by non–cytochrome P450 isoenzymes, and/or have lower potential to induce/inhibit various hepatic enzyme systems. A clear understanding of the pharmacokinetic properties of individual AEDs is essential in creating a safe and effective treatment plan for a patient.

Management of epilepsy during pregnancy: an update

The clinical management of women with epilepsy on antiepileptic drugs (AEDs) during pregnancy presents unique challenges. The goal of treatment is optimal seizure control with minimal in utero fetal exposure to AEDs in an effort to reduce the risk of structural and neurodevelopmental teratogenic effects. This paper reviews the following key issues pertaining to women with epilepsy during pregnancy: AED pharmacokinetics; clinical management of AEDs; seizure frequency; major congenital malformation; neurodevelopmental outcomes; perinatal complications; and breast feeding.

Phenytoin is an estrogen receptor α-selective modulator that interacts with helix 12

RATIONALE

Phenytoin (Dilantin(®); DPH) is used to treat epilepsy but causes estrogen agonist-antagonist-like side effects. We investigated the interaction of phenytoin with estrogen receptors (ERs) α and β by computational molecular docking, ER competition binding, transcriptional assays, and biological actions, comparing outcomes with estradiol (E2), estrone (E1), and tamoxifen (TMX).

EXPERIMENTAL

(1) The DPH docking to 3-dimensional crystal structures of the ERα ligand-binding domain (LBD) showed a high degree of structural complementarity (-57.15 calculated energy units, approximating kcal/mol) with the ligand-binding pocket, including a contact at leucine (L540) in helix 12. Estrogen receptor β showed slightly less favorable interactions (-54.27 kcal/mol), without contacting L450. Estradiol, E1, and TMX contact points with ERα and ERβ do not include L450. (2) Cellular actions: Incubation of cells transfected with ERα or ERβ and a luciferase promoter phenytoin was several orders weaker than E2 as an agonist through ERα and had no effect through ERβ. However, phenytoin at clinical concentrations (10(-11) to 10(-6) mol/L) powerfully antagonized action of E2 on ERα-expressing cells. Similarly, phenytoin at clinically effective concentrations marginally induced alkaline phosphatase by ERα- and ERβ-expressing endometrial cancer cells but at doses well below clinical effectiveness blocked E2-induced alkaline phosphatase. (3) ER competition: In Scatchard plots comparing phenytoin with 17β-estradiol against endometrial cancer cell cytosol E2-alone more effectively displaced labeled E2 than phenytoin, but phenytoin was approximately equimolar effective to E2 in inhibiting E2's displacement of the radiolabel, further confirming that phenytoin is a strong E2 antagonist.

CONCLUSIONS

At clinically effective concentrations, phenytoin is a strong ERα cell antagonist but a many-fold weaker agonist. Although it interacts with ERβ LBD residues, phenytoin has no effects on ERβ-only expressing cells. Docking studies indicate phenytoin interacts with the ERα LBD at the hinge of helix 12 and could thereby interfere with the entry of other ER ligands or with the mobility of helix 12, either of which actions could explain phenytoin's antagonism of ER-mediated E2 actions. Our results suggest an explanation for the broad profile of phenytoin's actions and raise possibilities for the use of phenytoin or congeners in the clinical management of ERα-dependent conditions.

Neuroendocrine aspects of catamenial epilepsy

This review describes the neuroendocrinological aspects of catamenial epilepsy, a menstrual cycle-related seizure disorder in women with epilepsy. Catamenial epilepsy is a multifaceted neuroendocrine condition in which seizures are clustered around specific points in the menstrual cycle, most often around perimenstrual or periovulatory period. Three types of catamenial seizures (perimenstrual, periovulatory and inadequate luteal) have been identified. The molecular pathophysiology of catamenial epilepsy remains unclear. Cyclical changes in the circulating levels of estrogens and progesterone (P) play a central role in the development of catamenial epilepsy. Endogenous neurosteroids such as allopregnanolone (AP) and allotetrahydrodeoxycorticosterone (THDOC) that modulate seizure susceptibility could play a critical role in catamenial epilepsy. In addition, plasticity in GABA-A receptor subunits could play a role in the enhanced seizure susceptibility in catamenial epilepsy. P-derived neurosteroids such as AP and THDOC potentiate synaptic GABA-A receptor function and also activate extrasynaptic GABA-A receptors in the hippocampus and thus may represent endogenous regulators of catamenial seizure susceptibility. Experimental studies have shown that neurosteroids confer greater seizure protection in animal models of catamenial epilepsy, especially without evident tolerance to their actions during chronic therapy. In the recently completed NIH-sponsored, placebo controlled phase 3 clinical trial, P therapy proved to be beneficial only in women with perimenstrual catamenial epilepsy but not in non-catamenial subjects. Neurosteroid analogs with favorable profile may be useful in the treatment of catamenial epilepsy.

Patient knowledge about issues related to pregnancy in epilepsy: a cross-sectional study

In 2009, new guidelines were established by the American Academy of Neurology regarding pregnancy in women with epilepsy. A questionnaire was developed to assess patient knowledge of current guidelines related to epilepsy and pregnancy. Patients were recruited from a single outpatient clinic in a large Canadian tertiary care center. Patients were eligible to participate if they were female, of reproductive age, had active epilepsy for at least 6 months and were not cognitively impaired. One hundred women completed the survey (response rate 87%) with a median score of 40%. A significant association was found between total score and years of education (p<0.001). Significant associations were not found between total score and epilepsy duration (p=0.37), previously being pregnant (p=0.22), and polytherapy (p=0.31). Patient knowledge of the impact of epilepsy on pregnancy is low. More knowledge translation efforts are required to increase knowledge of issues related to pregnancy for women with epilepsy.

Neurologists' and neurology residents' knowledge of issues related to pregnancy for women with epilepsy

We aimed to assess physician knowledge for 2009 guidelines established by the American Academy of Neurology and American Epilepsy Society regarding issues related to pregnancy for women with epilepsy. A questionnaire was developed and distributed to all neurologists and neurology residents practicing in a large Canadian health region serving a population of 1.4 million. Descriptive statistics were obtained and percentage of correct responses was calculated. Forty-five physicians completed the survey (response rate = 83.3%), with a median correct score of 50%. Residents were more likely (93.3%) to state that this information was important to their practice than staff physicians (40.0%). Overall knowledge of outcomes associated with specific AEDs was poor; less than half of the physicians correctly indicated which AEDs were associated with adverse outcomes for the majority of drug-related questions. We recommend multifaceted, interactive implementation strategies for increasing knowledge of guideline contents.

The role of neurosteroids in the pathophysiology and treatment of catamenial epilepsy

Catamenial epilepsy is a multifaceted neuroendocrine condition in which seizures are clustered around specific points in the menstrual cycle, most often around perimenstrual or periovulatory period. Generally, a twofold or greater increase in seizure frequency during a particular phase of the menstrual cycle could be considered as catamenial epilepsy. Based on this criteria, recent clinical studies indicate that catamenial epilepsy affects 31-60% of the women with epilepsy. Three types of catamenial seizures (perimenstrual, periovulatory and inadequate luteal) have been identified. However, there is no specific drug available today for catamenial epilepsy, which has not been successfully treated with conventional antiepileptic drugs. Elucidation of the pathophysiology of catamenial epilepsy is a prerequisite to develop specific targeted approaches for treatment or prevention of the disorder. Cyclical changes in the circulating levels of estrogens and progesterone play a central role in the development of catamenial epilepsy. There is emerging evidence that endogenous neurosteroids with anticonvulsant or proconvulsant effects could play a critical role in catamenial epilepsy. It is thought that perimenstrual catamenial epilepsy is associated with the withdrawal of anticonvulsant neurosteroids. Progesterone and other hormonal agents have been shown in limited trials to be moderately effective in catamenial epilepsy, but may cause endocrine side effects. Synthetic neurosteroids, which enhance the tonic GABA-A receptor function, might provide an effective approach for the catamenial epilepsy therapy without producing hormonal side effects.

Medications in pregnancy and lactation: part 1. Teratology

One of the least-developed areas of clinical pharmacology and drug research is the use of medication during pregnancy and lactation. This article is the first in a two-part series designed to familiarize physicians with many aspects of the drugs they commonly prescribe for pregnant and breast-feeding women. Almost every pregnant woman is exposed to some type of medication during pregnancy. Although the majority of pregnant and breast-feeding women consume clinically indicated or over-the-counter drug preparation regularly, only few medications have specifically been tested for safety and efficacy during pregnancy. There is scant information on the effect of common pregnancy complications on drug clearance and efficacy. Often, the safety of a drug for mothers, their fetuses, and nursing infants cannot be determined until it has been widely used. Absent this crucial information, many women are either refused medically important agents or experience potentially harmful delays in receiving drug treatment. Conversely, many drugs deemed "safe" are prescribed despite evidence of possible teratogenicity. Novel research and diagnostic applications evolving from the opportunities presented by the advances in genomics and proteomics are now beginning to affect clinical diagnosis, vaccine development, drug discovery, and unique therapies in a modern diagnostic-therapeutic framework-part of the new scientific field of theranostics. This review critically explores a number of recently raised issues in regard to the use of several classes of medications during gestation and seeks to provide a general and concise resource on drugs commonly used during pregnancy and lactation. It also seeks to make clinicians more aware of the controversies surrounding some drugs in an effort to encourage safer prescribing practices through consultation with a maternal-fetal medicine specialist and through references and Web sites that list up-to-date information.

An evaluation of pharmacists' knowledge of women's issues in epilepsy

OBJECTIVE

Although epilepsy affects men and women equally, there are many women's health issues in epilepsy. These issues challenge both the woman with epilepsy and the many health care professionals involved in her care. As antiepileptic drugs (AEDs) play a major role in the treatment of epilepsy, pharmacists can serve an important function in the health care of patients with this chronic disease. The goal of this educational project was to assess pharmacists' knowledge of women's issues in epilepsy using the Knowledge of Women's Issues and Epilepsy II (KOWIE-II) questionnaire.

METHODS

In this cross-sectional study we used the valid and reliable KOWIE-II questionnaire, a 10-item questionnaire on women's issues in general as well as pregnancy-related issues. A random sample of pharmacists registered in Ohio either were sent the KOWIE-II questionnaire or completed it prior to a live seminar. Demographic and practice-related data were collected. A percentage correct score was calculated per pharmacist.

RESULTS

Our sample consisted of 152 completed surveys. On the questionnaire, the overall average correct score was 60.3%. Nearly 75% of pharmacists had a correct score for the statement inquiring about the drug interaction between enzyme-inducing AEDs and contraceptives. Slightly less than 70% knew of the issue of AED-induced bone loss. Almost one-third (32.2%) of the respondents answered incorrectly when asked about the frequency of sexual dysfunction in women with epilepsy, though an even higher percentage chose "don't know." Most of the pharmacists (69.1%) stated "don't know" when asked about the relationship between hormones and seizure control. More than 70% correctly answered four of the six pregnancy-related statements (folic acid=77.0%, healthy babies=82.9%, continued AED adherence during pregnancy=86.8%, choice of AED during pregnancy=71.1%). Fewer pharmacists knew about vitamin K supplementation (57.9%), and even fewer answered the question on breastfeeding correctly (33.6%). Pharmacists who interacted with the most patients per month had the highest scores.

CONCLUSION

Pharmacists are in a key position to help women with epilepsy, and though there are some areas where pharmacists are generally knowledgeable about women's issues in epilepsy, there are still gaps in knowledge where educational interventions are clearly needed.

Antiepileptic drug therapy in pregnancy I: gestation-induced effects on AED pharmacokinetics

The ideal management of women with epilepsy during pregnancy involves achieving an optimal balance between minimizing fetal exposure to the deleterious influences of both antiepileptic drugs (AEDs) and of seizures. Women with increased seizures during pregnancy tend to have subtherapeutic AED concentrations. Multiple physiological changes during pregnancy influence drug disposition, including increased volume of distribution, increased renal elimination, altered hepatic enzyme activity, and a decline in plasma protein concentrations. Many of the AEDs are characterized by significant increases in clearance during pregnancy. Studies performed thus far provide convincing findings for significant increases in the clearance of lamotrigine and phenytoin during pregnancy; other studies support that phenobarbital, oxcarbazepine, and levetiracetam clearances also most likely increase during pregnancy. Therapeutic drug monitoring of lamotrigine with adjustment of dosages during pregnancy to maintain that individual's target concentration has been shown to decrease the risk for increased seizure frequency. Reports of seizure worsening with decreased concentrations of other AEDs have been reported but not studied in similar formal protocols. Future studies of formal pharmacokinetic modeling of AEDs during pregnancy, with assessment of maternal and fetal/newborn consequences, could provide an important step toward achieving effective drug dosing to maintain therapeutic objectives for the mother but at the same time minimize fetal drug exposure.

Women with epilepsy: hormonal issues from menarche through menopause

Epilepsy is a multilayered disorder complicated by numerous comorbid conditions and hormonal changes. More than 1.5 million girls and women with epilepsy face side effects that are compounded at different ages by menstruation, fertility, pregnancy, fetal health, bone health, and other health issues. Changes in hormonal balance during maturation, from menarche through menopause, affect seizure thresholds and antiepileptic drugs, and vice versa. This overview provides physicians with a background on the multiple issues relevant to women of all ages in the reproductive years, including those planning to conceive and those who are pregnant, and beyond the childbearing years.

Levetiracetam: part II, the clinical profile of a novel anticonvulsant drug

The objective of this article was to review and summarize the available reports on the profile of the novel anticonvulsant drug levetiracetam (LEV) in a clinical setting. Therefore, a careful search was conducted in the MEDLINE database and combined with guidelines from regulatory agencies, proceedings of professional scientific meetings, and information provided by the manufacturers. This article is devoted to the clinical pharmacology and clinical trials of LEV investigating its efficacy and safety as add-on therapy or monotherapy for various seizure types. Finally, results from postmarketing surveillance of LEV are briefly discussed. In general, LEV is shown to be a safe, broad-spectrum anticonvulsant drug with highly beneficial pharmacokinetic properties, a favorable long-term retention rate, and a high responder rate, indicating that LEV is an efficient therapeutic option for the treatment of several types of epilepsy.

Treatment with oxcarbazepine during pregnancy

BACKGROUND

Managing epilepsy during pregnancy is a critical challenge as maternal seizures may have deleterious effects on the fetus. While many patients with epilepsy have been managed successfully with antiepileptic drugs (AEDs), the potential teratogenicity of AEDs is a major concern. First-generation AEDs such as valproate have been associated with at least a 2-fold risk of fetal malformations compared with the general population. However, recent studies suggest that the newer AEDs given as monotherapy may have a lower teratogenic risk. The current case report adds to the growing experience of oxcarbazepine therapy in pregnant women with epilepsy.

REVIEW SUMMARY

This case report presents a 23-year-old female with a history of complex partial seizures (CPS) and mild depression. In high school, she had 2 initial tonic-clonic seizures and was placed on phenytoin monotherapy. She was subsequently placed on combination therapy (phenytoin + gabapentin) and was maintained on it for several years. Preceding a planned pregnancy, the patient was switched to oxcarbazepine and tapered off both phenytoin and gabapentin. The patient was maintained on oxcarbazepine monotherapy with a seizure-free pregnancy and delivered a normal, healthy baby girl. The patient breast-fed the infant for 6 months, supplemented with infant formula without any adverse effects. Subsequently, the patient has had a healthy second child while receiving oxcarbazepine during her pregnancy.

CONCLUSION

Although there are very limited data in the literature, this case illustrates that a patient with a history of CPS can be treated with oxcarbazepine with no adverse effects during and after pregnancy.

Therapeutic monitoring of antiepileptic drugs during pregnancy and in the postpartum period: is it useful?

As in all patient populations, epilepsy is common in pregnant women. Consequently, approximately 1 in 200 pregnancies is exposed to antiepileptic drugs (AEDs). Although exposure to AEDs in utero has been associated with an increased risk of major fetal malformations, most women with epilepsy require medication throughout pregnancy, since seizures themselves may be potentially harmful not only for the mother but also for the developing fetus. Physiological changes during pregnancy result in a reduction in the serum concentrations of most AEDs, particularly in late pregnancy. Changes in protein binding lead to a greater reduction in total than free (active) drug concentrations. Pharmacokinetic changes in pregnancy show interindividual variability and are not well understood for most newer AEDs. However, recent studies have shown that changes in lamotrigine clearance are particularly marked, with increases in each trimester and a significant fall in plasma concentrations, leading to consequent breakthrough seizures in some women. Concentrations may then rise precipitously after delivery, leading to symptoms of lamotrigine toxicity. Therapeutic drug monitoring could theoretically guide adjustment of AED dosage to achieve good seizure control while minimising fetal exposure, although there are several limitations to such monitoring. Firstly, there are wide interindividual variations in serum drug concentrations, with seizure control often correlating poorly with a given therapeutic range. Secondly, therapeutic ranges have not been well defined for newer AEDs and their measurement is often not always available. Thirdly, for highly protein-bound drugs, although measurement of free drug concentrations may more accurately reflect drug availability during pregnancy than total drug concentrations, assays for this are not always available and may be unreliable. Thus, it may be useful, prior to pregnancy, to establish the total and free drug concentrations required to achieve optimal seizure control in a given individual. Regular monitoring of AEDs has been advocated in each trimester and shortly after delivery, with adjustment of dosage to avoid seizure precipitation during pregnancy or symptoms of toxicity after birth. More frequent monitoring has been recommended for lamotrigine. However, aggressive drug monitoring of any AED has yet to be proven to be effective in improving seizure control or care. Furthermore, higher doses may be associated with a greater potential for teratogenicity and it is not yet known whether longer term adverse effects may be related to in utero exposure in the latter half of pregnancy. There is limited evidence about the relationship of maternal serum drug concentrations and teratogenicity. While there is a theoretical role for therapeutic drug monitoring in improving the risk-to-benefit ratio of AED therapy during pregnancy, there are many practical limitations. Future work is needed to clarify its role in improving seizure control during pregnancy and identifying serum drug concentrations that may be considered safe for fetal exposure.

The impact of antiepileptic drug therapy on steroidal contraceptive efficacy

Women with epilepsy face unique challenges in maintaining steroidal contraceptive efficacy because some antiepileptic drugs (AEDs) increase the rate of hepatic metabolism of contraceptive steroids, leading to higher potential for contraceptive failure in this population. Planned pregnancy is of great clinical and social importance for women with epilepsy because of the increased risk of birth defects from fetal exposure to AEDs. Current clinical guidelines for contraceptive management in women with epilepsy provide misleading information by focusing on the estrogen content of the formulation, which regulates the menstrual cycle, rather than on the progestin content of the formulation, which provides contraceptive efficacy. This article reviews studies of AED-contraceptive interaction and misconceptions about maintaining contraceptive efficacy and makes recommendations for contraceptive management in women with epilepsy who receive concomitant AED therapy.

Women are not the same as men: specific clinical issues for female patients with bipolar disorder

Women are not the same as men. While this observation can be considered to subjectively manifest in many different ways, objectively a greater tendency for bipolar II disorder, depressive symptoms, a rapid cycling course, and the consequences of being of child-rearing age can all represent additional challenges for female patients. Despite much recent interest in improving the management of patients with bipolar disorder, relatively little guidance exists relating to female-biased gender-specific issues. This review article will explore how female gender can influence bipolar disorder and its treatment and will focus on epidemiologic differences, the relevance to clinical presentation of events unique to women (particularly contraception, pregnancy, and lactation), and the importance of considering gender when making decisions about the pharmacological management of mood. All female patients should receive counseling regarding family planning and sexually transmitted diseases, as well as the risks of and treatment options during pregnancy and postpartum. Wherever possible, treatment choices should be made in a partnership between patient and clinician.

The significance of folic acid for epilepsy patients

The following is a comprehensive review of the current understanding of the many important roles of folic acid in the health of patients with epilepsy. A review of past and current literature reveals that folic acid plays important roles in the areas of hematology, neurology, development, and reproduction. Also highlighted are new areas for exploration.

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.

Safety of the newer antiepileptic drug oxcarbazepine during pregnancy

OBJECTIVE

Seizure control in pregnant women with epilepsy is vital, as maternal seizures may have deleterious consequences. The treatment of pregnant women with epilepsy is, however, complicated by the teratogenicity of older antiepileptic drugs (AEDs). In this review, the safety of the newer AED oxcarbazepine during pregnancy is assessed based on published pregnancy outcome data. Other relevant safety issues, such as oxcarbazepine pharmacokinetics during pregnancy and the compatibility of oxcarbazepine treatment with breastfeeding, are also discussed.

METHODS

Literature searches of the following databases were performed: MEDLINE, EMBASE, eNova, NOWIMA (an internal Novartis Germany database), Derwent Drug File, SciSearch and BIOSIS. Identified publications were examined for original data reporting rates of foetal malformation following maternal exposure to oxcarbazepine as monotherapy or adjunctive therapy.

RESULTS

Relevant publications reporting data from the worldwide Novartis safety database and pregnancy registries or study centres in six countries were identified. A total of 248 pregnancies involving maternal exposure to oxcarbazepine monotherapy and 61 involving adjunctive therapy were reported. There were six malformations among the monotherapy group, equating to a malformation rate of 2.4% (6/248). The malformation rate reported in the general population is 2-4%. There were four malformations associated with oxcarbazepine adjunctive therapy, equating to a malformation rate of 6.6% (4/61).

CONCLUSIONS

This literature review suggests that, compared with newborns in the general population, the newborns of women receiving oxcarbazepine monotherapy during pregnancy do not appear to show an increased risk for malformations. However, the number of pregnancies involving maternal exposure to oxcarbazepine identified by this review is not sufficient to draw definitive conclusions. Additional information from large-scale pregnancy registries is required to confirm the safety profile of oxcarbazepine as monotherapy or adjunctive therapy during pregnancy.

Neostigmine, but not Metoclopramide, Abolishes Ethosuximide-Induced Functional Gastrointestinal Disturbances

Ethosuximide is a drug used for the treatment of absence seizures. Its prolonged application leads to gastrointestinal (GI) disturbances. The purpose of the present study was to determine the severity and nature of the disturbances, as well as the influence exerted upon them by neostigmine methylsulfate and metoclopramide. The drug-induced alterations, occurring in the rat GI tract, were registered by X-ray contrast examination. In vitro experiments were carried out on isolated GI smooth muscle (SM) preparations. The latter revealed that the drug hyperpolarized the SM tissues and inhibited their contractile activity. X-rays of ethosuximide-treated rats showed GI hypotonia, disturbed peristalsis and decreased evacuation activity. The inhibition of the GI functions was associated with hyperpolarization of SM and a reduction in Ca(2+) influx, ensuring spontaneous contractile activity. The application of neostigmine methylsulfate significantly removed ethosuximide-induced functional GI disturbances in rats treated for 15 days with ethosuximide.

[Drug interactions with antiepileptic agents]

Drug interactions with antiepileptic agents are based in large part on pharmacokinetic mechanisms. Most prominent are induction or inhibition of enzymes of the cytochrome P450 (CYP) system, which is of central importance for metabolic elimination of lipophilic xenobiotics. Potent inductors of CYP isoenzymes are carbamazepine, phenobarbital, phenytoin, and primidone, thereby decreasing not only their own plasma levels and efficacy but also that of other antiepileptics and other drugs. Felbamate, oxcarbazepine, and topiramate are weak inductors of the CYP isoenzyme 3A4, whereas they inhibit CYP2C19. Valproic acid is a potent inhibitor of several CYP isoenzymes and glucuronyltransferases, resulting in an increase in plasma concentrations and toxicity of antiepileptics and other drugs. Antiepileptics that are not involved in drug interactions include gabapentin, levetiracetam, and vigabatrine. The P-glycoprotein may mediate the exit of antiepileptics from the brain. This transport mechanism is inhibited by carbamazepine, which may explain the enhanced clinical efficacy of a combination of carbamazepin with other antiepileptics. Other possible pharmacokinetic interactions are precipitation of antiepileptics in the stomach by antacids or sucralfate and displacement from plasmaprotein binding of one antiepileptic agent by another. Therapeutic drug monitoring (TDM) may be helpful in assessing pharmacokinetic drug interactions. Pharmacodynamic interactions appear to be responsible for the enhanced efficacy of antiepileptic combination therapy. In prescribing drugs, their spectrum of interactions has to be known.

Experimental studies on reproductive toxicologic effects of lamotrigine in mice

BACKGROUND

Virtually all antiepileptic drugs (AED) tested so far have been found to be teratogenic. The second generation AED possess a number of therapeutic advantages over the older ones. There are, however, very little data on their effects on embryonic development. A recent report suggests that lamotrigine (LTG) can be teratogenic to human fetuses. With only a few cases of prenatal exposure to LTG in the record, however, it has not been possible to establish a recognizable pattern of malformations in the infants of LTG-treated mothers.

OBJECTIVES

The objectives of the present study were to evaluate the reproductive toxic effects of LTG .

RESULTS

Single (50-200 mg/kg) or multiple doses (25, 50, 75 mg/kg) of LTG were administered by intraperitoneal (i.p.) injection (note that the therapeutic administration is oral) to groups of TO mice on gestation day (GD) 7 or 8. Fetuses were collected on GD 18. Maternal toxic effects including a dose-related mortality, a high incidence of abortion, embryo lethality, congenital malformations and intrauterine growth retardation (IUGR) were observed in the LTG-treated group. Administration of LTG in multiple low doses resulted in a better maternal survival and increased incidence of embryonic resorption and malformations with increasing dose; IUGR was significant but not dose-dependent. The malformations characteristic of the LTG multiple low dose group fetuses included maxillary-mandibular hypoplasia, exencephaly, cleft palate, median facial cleft, urogenital anomalies and varying degrees of caudal regression. Skeletal malformations and developmental delay of the skeleton were observed both in single and multiple dose groups.

CONCLUSIONS

The results of this study indicate that LTG administered i.p. at high doses can induce intrauterine growth retardation and at low multiple doses causes a dose-dependent increase in embryonic resorption, craniofacial and caudal malformations as well as maternal toxicity in the mouse. Previous studies in other laboratories have used oral route of exposure and concluded that there are no teratogenic effects of LTG at dose levels that are not maternally toxic.

Seizure disorders in pregnancy

This article discusses seizure disorders in pregnancy. Seizure disorder affects 1.1 million women of reproductive age in the United States. In 1995, the annual cost of treatment of patients who had epilepsy was estimated to be 12.5 billion dollars. Seizures are disorganized firing of neural cells. Epilepsy is the presence of two or more seizures in the absence of an identifiable cause for the seizures (ie, no intracranial or metabolic abnormality). Epilepsy has an impact on many aspects of women's health, particularly with respect to reproduction. The management of women who have epilepsy during pregnancy is the focus of this article.

Broadening the perspective: treating the whole patient

Seizures are not the only obstacles that individuals with epilepsy must overcome. Treatment of epilepsy must take into consideration that patients with epilepsy often face some form of depression, such as peri-ictal depression, ictal depression, interictal depression, or postictal depression, as well as an elevated risk of suicide. Elderly patients, in particular, require special consideration, since aging affects pharmacokinetics and pharmacodynamics; women of childbearing age also require additional counseling. Treatment strategies that focus only on seizure reduction are inadequate and unsuccessful in up to one half of all patients with epilepsy. Epilepsy requires broad treatment strategies that address the needs of the whole patient. Age, genetic factors, gender, diet, use of alcohol and nicotine, comorbidities, and polypharmacy all are important factors to consider in determining a successful epilepsy treatment strategy. Epilepsy affects many aspects of psychosocial function, and optimal outcomes require that the needs of the whole patient be adequately addressed.