Chapter 6 Contraception in Women with Epilepsy

Epilepsy and Issues Related to Reproductive Health

Sexual disorders are prevalent and vary in men and women with epilepsy (WWE). Infertility and reproductive abnormalities are twice as common in females with epilepsy. Antiepileptic medications and seizures can both have an impact on sexual health in people with epilepsy. Seizures can alter the release of pituitary and hypothalamic hormones, and some antiepileptic drugs (AEDs) can alter sex steroid hormones (gonadal steroids and gonad corticoids). Females with epilepsy are more susceptible to menstrual cycle irregularity and polycystic ovary syndrome. Females and males had lower reproductive rates, and the causes are likely psychological and physiological, with epilepsy and AEDs again playing a role. Sexual disorders are common in WWE and men with epilepsy and can be caused by psychological, physical, or social factors. Specialists must address the gender-based biology of epilepsy and the impact of AEDs on sexual well-being to offer the best treatment possible for patients with epilepsy, particularly women of sexual maturity.

Counseling on the Need for Folic Acid in Adolescents With Epilepsy

Background and Objectives

Folic acid is an important supplement to take for women with epilepsy on antiseizure medications (ASMs). Determination of baseline counseling given to women with epilepsy and the association with folic acid being recommended were evaluated. Factors surrounding the association were reviewed.

Methods

An exploratory retrospective review of women with epilepsy seen at a large Midwestern pediatric institution was performed between January 2018 and January 2020.

Results

Patients who received preconception counseling were more likely to be given a recommendation to take folic acid. Patients on more than 1 ASM were likely to receive counseling. Patient age and race were associated with having folic acid recommended.

Discussion

Providing preconception counseling for women with epilepsy is associated with an increased recommendation and prescription of folic acid. Further evaluation into possible disparities to receiving a folic acid recommendation is needed.

Epilepsy Care in Transgender Patients

PURPOSE OF REVIEW

The goal of this review is to outline the main considerations when treating transgender patients with epilepsy. Points to be addressed include the gender affirming hormone therapy regimens and how they interact with anti-seizure medications and seizure control, as well as common co-morbidities in the transgender epilepsy population.

RECENT FINDINGS

Gender affirming hormone therapy (GAHT) may affect seizure control directly, due to proconvulsant or anticonvulsant properties. GAHT may interact with anti-seizure medications; most notably, estrogen will decrease serum concentration of lamotrigine. Enzyme-inducing anti-seizure medications may decrease hormone levels, potentially interfering with goals of GAHT. Transgender epilepsy patients are at risk for co-morbidities such as decreased bone mineral density and depression. There are minimal direct studies on treatment or outcomes in the transgender epilepsy population. Providers must be knowledgeable about the bi-directional interactions between gender affirming hormone therapy and anti-seizure medications, as well as direct hormonal influences on seizure control. Future research should directly evaluate outcomes in transgender epilepsy patients with regard to seizure control, success of hormone therapy, and management of co-morbidities, to further educate providers and patients how to best manage their healthcare.

Hypogonadism in Women with Prader-Willi Syndrome-Clinical Recommendations Based on a Dutch Cohort Study, Review of the Literature and an International Expert Panel Discussion

Prader-Willi syndrome (PWS) is a rare neuroendocrine genetic syndrome. Characteristics of PWS include hyperphagia, hypotonia, and intellectual disability. Pituitary hormone deficiencies, caused by hypothalamic dysfunction, are common and hypogonadism is the most prevalent. Untreated hypogonadism can cause osteoporosis, which is already an important issue in PWS. Therefore, timely detection and treatment of hypogonadism is crucial. To increase understanding and prevent undertreatment, we (1) performed a cohort study in the Dutch PWS population, (2) thoroughly reviewed the literature on female hypogonadism in PWS and (3) provide clinical recommendations on behalf of an international expert panel. For the cohort study, we retrospectively collected results of a systematic health screening in 64 female adults with PWS, which included a medical questionnaire, medical file search, medical interview, physical examination and biochemical measurements. Our data show that hypogonadism is frequent in females with PWS (94%), but is often undiagnosed and untreated. This could be related to unfamiliarity with the syndrome, fear of behavioral changes, hygienic concerns, or drug interactions. To prevent underdiagnosis and undertreatment, we provide practical recommendations for the screening and treatment of hypogonadism in females with PWS.

Contraception for Women With Psychiatric Disorders

OBJECTIVE

Mental health care for women includes decision support to prepare for major life events, including preconception planning for treatment during pregnancy and the postpartum period. The authors discuss contraceptive choices and their effectiveness, side effects, and impact on psychiatric symptoms. The Centers for Disease Control and Prevention's recommendations, Medical Eligibility Criteria for Contraceptive Use, provided the structure for review of contraceptive choices.

METHODS

A search of PsycINFO, PubMed, Embase, and Scopus was conducted for publications on the management of contraception for women with mental illness. Publications were selected if they included, based on the authors' consensus, data supporting evidence-based care important for psychiatrists who treat women desiring contraceptives.

RESULTS

The majority of women choose combined oral contraceptives. Although long-acting reversible contraceptives (implants, intrauterine devices) are associated with low failure rates, favorable safety profiles, rapid return to fertility after removal, and few contraindications, they are chosen by only 14% of women. All methods are acceptable for women with depression, although medical comorbidities may dictate a specific type. The impact of hormonal contraceptives on the risk for depression is controversial; however, clinical studies and randomized placebo-controlled trials of women with psychiatric disorders have generally reported similar or lower rates of mood symptoms in hormonal contraceptive users compared with nonusers. Although interactions between psychotropic drugs and contraceptives are rare, clozapine, anticonvulsants, and St. John's Wort are exceptions.

CONCLUSIONS

Proactive management of mental illness, contraception, and pregnancy improves a woman's capacity to function and optimizes her mental and reproductive health.

Gynecologic Management of Adolescents and Young Women With Seizure Disorders: ACOG Committee Opinion, Number 806

Seizure disorders frequently are diagnosed and managed during adolescence; therefore, obstetrician-gynecologists who care for adolescents should be familiar with epilepsy and other seizure disorders, as well as antiepileptic drugs. Patients diagnosed with seizure disorders during childhood may have increased seizure activity with puberty and menarche due to the neuroactive properties of endogenous steroid hormones. Compared with patients without epilepsy, patients with epilepsy are more likely to experience anovulatory cycles, irregular menstrual bleeding, and amenorrhea. Although hormonal suppression should not be initiated before puberty or menarche, prepubertal counseling may be appropriate, and obstetrician-gynecologists may work with young patients and their families to develop a plan to initiate with menarche. Additionally, obstetrician-gynecologists should be aware of any medication changes, including antiepileptics, for adolescent patients with seizure disorders. Research on hormonal therapy for the treatment of epilepsy is scant; however, the anticonvulsant properties of various progestins have been explored as potential treatment. There is no conclusive evidence that combination hormonal contraception increases epileptic seizures, and epilepsy itself poses no increased risk of an adverse outcome for those using combined oral contraceptive pills, the contraceptive patch, or a contraceptive ring. Because many antiepileptic drugs are teratogenic, discussing sexual health with and providing effective contraceptive choices to this population is critical. Obstetrician-gynecologists should work with patients with seizure disorders to develop a plan when pregnancy occurs.

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.

Fertility optimization in women with cancer: from preservation to contraception

Advances in the early diagnosis and treatment of cancer have reduced mortality rates and improved patient survival. For this reason, professionals from different areas have strived to implement actions to increase patient quality-of-life during and after cancer treatment. Among these measures, integral attention in reproductive health is one of the main points for the inclusion, safety, and autonomy of female patients. The approach to fertility in these cases should include counseling on fertility preservation and contraceptive options. Oocyte/embryo freezing is an effective technique that does not delay the start of cancer treatment, since controlled ovarian stimulation can be initiated at any stage of the menstrual cycle. At the same time, contraceptive counseling should be conducted based on the eligibility criteria established by the World Health Organization and the Centers for Disease Control and Prevention. However, there is still a lack of studies on (i) the suitability of contraceptives to patients of reproductive age with relatively frequent tumors (lymphoma, leukemia, bone cancer), and (ii) the use of contraceptive concurrently with chemotherapeutic agents. Therefore, the choice of contraceptive method should consider other factors such as tumor type, thrombogenic risk factors linked to cancer/chemotherapy, immunosuppression, blood disorders (thrombocytopenia/anemia), bone mass reduction, metabolic/cardiovascular effects, and drug interaction.

Sexual and Reproductive Health in Patients with Schizophrenia and Bipolar Disorder

INTRODUCTION

People with schizophrenia and bipolar disorder (BD) have a high risk of unwanted pregnancies and abortions, due to their condition of vulnerability or hypersexuality (common in BD). This is associated with difficulty in planning their actions and lack of sex education and counselling by medical personnel, and can lead to adverse obstetric outcomes and inability to care adequately for their children.

OBJECTIVE

To describe the characteristics in terms of sexual and reproductive health, and the use of contraception and counselling in psychiatric consultations, in a sample of patients with BD and schizophrenia in Medellin, Colombia.

METHODS

Observational cross-sectional study. We included the 160 participants from the clinical trial, "The effects of a multimodal intervention programme in patients with bipolar disorder and schizophrenia", who were recruited from the mood and psychosis disorders group clinic at Hospital Universitario de San Vicente Fundación in Medellin. They were contacted by phone by a third-year psychiatry resident, who applied a survey about the characteristics of their sex life, contraception and reproduction.

RESULTS

Almost all of the patients with schizophrenia were single, had no undergraduate studies and were unemployed. No significant differences were found regarding the age of starting sexual relations when comparing by diagnosis and gender. Almost all patients with schizophrenia and almost half of the patients with BD reported not having an active sexual life. Almost all of those who admitted to having an active sexual life claimed to always use contraception; in the BD group, only 48.8% of single women admitted to using contraception and a little over half of men stated that they used a condom when having sex. A quarter of the pregnancies were unplanned. Although the majority of the patients stated that they had never received information about family planning in the consultations with their psychiatrist, 57.4% of the patients with BD and 78.8% of those who had schizophrenia, considered themselves to be well informed on the subject.

CONCLUSIONS

Patients with mental illness have cognitive and behavioural alterations that affect their sexual and reproductive lives. Psychiatrists should therefore address this issue, to ensure education in areas such as contraception, family planning and sexually transmitted diseases and help safeguard the safety and quality of life of their patients.

Women with epilepsy: clinically relevant issues

Women with epilepsy (WWE) face specific challenges throughout their lifespan due to the effects of seizures and antiepileptic drugs on hormonal function, potentially affecting both sexual and reproductive health. This review article addresses the most common issues of practical relevance to clinicians treating WWE: epidemiology and clinical presentations (including catamenial epilepsy), contraception, reproductive and sexual dysfunction, pregnancy, lactation, menopause-related issues (including bone health), and mental health aspects. Awareness of these gender-specific issues and implementation/adaptation of effective interventions for WWE results in significantly improved health-related quality of life in this patient population.

Contraception for women with epilepsy: counseling, choices, and concerns

Approximately 50% of all pregnancies in women with epilepsy (WWE) occur unplanned. This is worrying, given the increased occurrence of obstetrical complications in WWE, including the risk of seizures and their possible consequences for both the mother and the unborn child. Hormonal contraception is usually regarded as highly effective, but it is subject to numerous bidirectional drug interactions with several antiepileptic drugs. These interactions may lead to loss of seizure control or contraceptive failure. Further concerns are loss of bone mineral density and increased seizure activity due to hormonal effects. Many physicians lack sufficient knowledge regarding these issues, and most WWE have never received adequate counseling. Moreover, several studies show that a large proportion of WWE do not take their medicines regularly. This article reviews all of these issues and offers practical recommendations for the management of contraception in WWE.

Canadian Contraception Consensus (Part 3 of 4): Chapter 8 - Progestin-Only Contraception

OBJECTIVE

To provide guidelines for health care providers on the use of contraceptive methods to prevent pregnancy and on the promotion of healthy sexuality.

OUTCOMES

Overall efficacy of cited contraceptive methods, assessing reduction in pregnancy rate, safety, ease of use, and side effects; the effect of cited contraceptive methods on sexual health and general well-being; and the relative cost and availability of cited contraceptive methods in Canada.

EVIDENCE

Published literature was retrieved through searches of Medline and The Cochrane Database from January 1994 to January 2015 using appropriate controlled vocabulary (e.g., contraception, sexuality, sexual health) and key words (e.g., contraception, family planning, hormonal contraception, emergency contraception). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies published in English from January 1994 to January 2015. Searches were updated on a regular basis in incorporated in the guideline to June 2015. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

The quality of the evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). CHAPTER 8: PROGESTIN-ONLY CONTRACEPTION: Summary Statements Recommendations.

Lack of Pharmacokinetic Interactions Between Macitentan and a Combined Oral Contraceptive in Healthy Female Subjects

Macitentan, a dual endothelin receptor antagonist used in pulmonary arterial hypertension, induces cytochrome P450 (CYP) 3A at supratherapeutic concentrations in vitro. Most combined oral hormonal contraceptives (OCs) are CYP3A substrates and their efficacy can be affected by CYP3A inducers. This randomized crossover study assessed possible pharmacokinetic (PK) interactions between macitentan and an OC containing ethinyl estradiol and norethindrone (or norethisterone). Twenty-six healthy women received a single oral dose of OC alone (reference) and concomitantly with 10 mg macitentan at steady state (test). No PK interaction was concluded if the 90% confidence intervals (CIs) of geometric mean ratios (GMRs; test/reference) of the peak plasma concentration (Cmax ) and the exposure from 0 to infinity (AUC0 - ∞ ) to the OC components were within the equivalence limits of 0.8 to 1.25. Cmax and AUC0-∞ of the OC were within the equivalence limits. For ethinyl estradiol, GMRs (90%CIs) of Cmax and AUC0-∞ were 0.92 (0.85-0.99) and 0.95 (0.90-0.99). For norethindrone, these values were 1.02 (0.95-1.09) and 1.04 (0.98-1.09), respectively. Overall, study treatments were well tolerated. No major changes from baseline in safety parameters were reported in either treatment. Macitentan does not affect the PK of OCs.

Advances in epilepsy treatment: lacosamide pharmacokinetic profile

Lacosamide (LCM) is a functionalized amino acid specifically developed for use as an antiepileptic drug (AED) and is currently indicated as adjunctive treatment for partial-onset seizures in adults with focal epilepsy (maximum approved dose 400 mg/day). Characterization of the pharmacokinetic profile is an important aspect in the development of LCM. Studies in healthy subjects and in patients with focal epilepsy have established that LCM has several favorable pharmacokinetic characteristics, including rapid absorption and high oral bioavailability not affected by food, linear and dose-proportional pharmacokinetics, low inter- and intraindividual variability, low plasma protein binding, renal elimination, and a low potential for clinically relevant pharmacokinetic drug-drug interactions both with AEDs and other common medications. Studies have demonstrated bioequivalence among the three LCM formulations (oral tablets, oral solution, and solution for intravenous (IV) infusion), allowing direct conversion to or from oral and IV administration without titration. Thus, the favorable and predictable pharmacokinetic profile and bioequivalence of LCM formulations, coupled with the low potential for clinically relevant pharmacokinetic drug-drug interactions, make LCM an easy-to-use adjunctive treatment for the management of patients with focal epilepsy.

A mixed-methods exploration of the contraceptive experiences of female teens with epilepsy

PURPOSE

We explored the contraceptive experiences of female teens with epilepsy, including their knowledge and perceptions of interactions between antiepileptic drugs and hormonal contraception and contraceptive decision-making processes.

METHOD

From November 2012 to May 2013, we conducted one online survey (n=114) and 12 online focus group discussions (n=26) with female teens with epilepsy about their contraceptive experiences and unmet needs. Survey data were analyzed using descriptive statistics and focus group transcripts were analyzed thematically using modified grounded theory methods.

RESULTS

Both survey and focus group participants reported believing that interactions between epilepsy medications and hormonal contraceptives could lead to reductions in contraceptive efficacy and seizure control. However, their knowledge about these types of medication interactions was often incomplete. Many study participants viewed contraceptive decision making as a difficult process, and some participants reported avoiding hormonal contraceptives because of potential interactions with antiepileptic drugs. Study participants reported relying on health care providers and parents for contraceptive decision-making support. Focus group participants also reported they wanted health care providers to provide more in-depth and comprehensive counseling about contraception, and that they desired peer support with contraceptive decisions.

CONCLUSION

The ability to make informed contraceptive decisions is important for teens with epilepsy as interactions between anti-epileptic drugs and hormonal contraceptives can impact seizure occurrence and lead to an increased risk of unplanned pregnancy. Guidance for providers offering contraceptive care to this population is needed, as well as a contraceptive support tool that empowers teens with epilepsy to advocate for desired health care.

Effects of ponesimod, a selective S1P1 receptor modulator, on the pharmacokinetics of a hormonal combination contraceptive

PURPOSE

To determine the effects of steady-state concentrations of the selective S1P1 receptor modulator ponesimod on the pharmacokinetics (PK) of a single dose of a combined oral contraceptive, containing 1 mg norethisterone (NET) and 35 μg ethinyl estradiol (EE) and to investigate the effects on heart rate at different ponesimod doses within an up-titration regimen prior to co-administration of the contraceptive.

METHODS

Twenty-two healthy women (age: 29-60 years) received twice a single oral dose of the combined oral contraceptive, alone or in combination with multiple doses of 40 mg ponesimod attained by an up-titration regimen. Heart rate (HR) effects were assessed on the first day of each up-titration level. PK parameters of NET and EE were determined by non-compartmental analysis.

RESULTS

Geometric mean ratios (ponesimod and contraceptive / contraceptive alone) of Cmax and AUC0-24 of NET were 0.87 (90 % CI: 0.80, 0.94) and 0.84 (90 % CI: 0.76, 0.93), respectively. Geometric mean ratios of Cmax and AUC0-24 of EE were 0.94 (90 % CI: 0.86, 1.03) and 0.95 (90 % CI: 0.89, 1.01), respectively. The maximum mean HR reduction after the first dose of 10 mg ponesimod was 12.4 bpm (SD ± 6.2) at 2.5 h post-dose. On Day 4 (first dose of 20 mg) and Day 7 (first dose of 40 mg) the maximum mean HR reduction was 4.3 bpm (SD ± 5.7) and 1.4 (SD ± 6.4), respectively, at 2.5 h post-dose compared to baseline.

CONCLUSION

No clinically relevant PK interactions between ponesimod and the combined oral contraceptive were observed, therefore, efficacy of hormonal contraceptives is not expected to be affected by concomitant administration of ponesimod. The up-titration regimen showed that HR reductions are diminished upon repeated ponesimod administration.

Ideal characteristics of an antiepileptic drug: how do these impact treatment decisions for individual patients?

Effective management of epilepsy requires a holistic approach that takes into account the needs of the individual patient. Antiepileptic drug (AED) treatment must therefore look beyond efficacy to ensure that the patient's overall health status and quality of life (QoL) are optimized. Because the primary objective of AED treatment is to control seizures over the long term, the ideal AED should, first and foremost, demonstrate sustained efficacy and favourable tolerability. In addition, it should have a broad spectrum of activity; its pharmacokinetic profile should be stable and predictable and allow the option of once-daily dosing; and it should not interact with other medications and concomitant AEDs. Because the efficacy of first-line AEDs is broadly comparable, choice of treatment should be based on the individual patient's specific clinical characteristics. In particular, the primary and secondary prevention of comorbid conditions should be taken into consideration, because this can reduce the risk of mortality and improve health outcomes and QoL. Treatment selection must also take into account the patient's particular lifestyle and priorities, to maximize the likelihood of long-term treatment adherence. Advances in genetic testing may help inform choice of treatment - not only by elucidating a patient's underlying aetiology, but also by helping to avoid unnecessary side effects. Although certain patient populations (e.g. women of childbearing potential, adolescents, the elderly) require particular consideration when choosing the most appropriate treatment, every patient's unique clinical characteristics and personal circumstances must be taken into account to ensure treatment success and optimize their QoL.

Continuation rates and complications of intrauterine contraception in women diagnosed with bipolar disorder

OBJECTIVE

To estimate continuation rates, complications, and psychiatric hospitalizations among women with bipolar disorder using levonorgestrel-releasing or copper-containing intrauterine devices (IUDs) as compared with those using depot medroxyprogesterone acetate or sterilization for birth control.

METHODS

Data for this cohort study were obtained from a nationwide health insurance claims database on an employed, commercially insured population. Women aged 18-44 years with a prior diagnosis of bipolar disorder (n=849) who were using the levonorgestrel intrauterine system, a copper-containing IUD, depot medroxyprogesterone acetate, or sterilization were evaluated. Outcomes included continuation rates over a 12-month interval, infectious and noninfectious complications, and hospitalizations for bipolar disorder or depression.

RESULTS

Women using an IUD were more likely than those using depot medroxyprogesterone acetate to continue the method for at least 12 months (copper-containing IUD, 86%; levonorgestrel intrauterine system, 87%). In comparison, only 31% of those who initiated depot medroxyprogesterone acetate received three more injections during the next year (P<.001). No significant differences were noted in infectious or noninfectious complications by contraceptive type. Finally, no differences were observed in the number of hospitalizations for bipolar disorder or depression among the four contraceptive groups.

CONCLUSION

More women with bipolar disorder continued using IUDs at one year than women using depot medroxyprogesterone acetate. The rates of complications and psychiatric hospitalizations were not different among women using an IUD, depot medroxyprogesterone acetate, or sterilization.

LEVEL OF EVIDENCE

II.

Concepts of contraception for adolescent and young adult women with chronic illness and disability

Sexual behavior is common in adolescents and young adults with or without chronic illness or disability, resulting in high levels of unplanned pregnancy and STDs. Individuals with chronic illness or disability should not receive suboptimal preventive health care. These individuals have a need for counseling regarding issues of sexuality and contraception. Sexually active adolescent and young adult women can be offered safe and effective contraception if they wish to avoid pregnancy. Women with chronic illnesses and disabilities who are sexually active should also be offered contraception based on their specific medical issues. Condoms are also recommended to reduce STD risks. Table 36 summarizes basic principles of contraception application for specific illnesses, which have been identified since the release of the combined OC in 1960. Clinicians should also consider the noncontraceptive benefits of this remarkable and life-changing technology that allows all reproductive age women to improve their lives, including those with chronic illnesses and disabilities.

Sex-gender research sensitivity and healthcare disparities

Authors Nieuwenhoven and Klinge (Journal of Women's Health 2010;19:1-6) argue that despite advances, sex and gender are not well treated in the biomedical literature. Many studies in which males and females are represented do not address the similarities or differences between sexes, sometimes adjusting for (thereby obscuring) sex differences and sometimes ignoring sex altogether. Women continue to be underrepresented in randomized drug trials, excluded from some by potential reproductive effects, and perhaps frightened from others by IRB-required warnings. Although recognized, sex disparities in treatment, for example, for acute cardiac syndrome, persist. As electronic abstracts become a prime means of communicating research results, they must adequately and accurately represent a study's findings.

Estrogen increases latencies to seizures and levels of 5alpha-pregnan-3alpha-ol-20-one in hippocampus of wild-type, but not 5alpha-reductase knockout, mice

Sex steroids can influence seizures. Estrogen (E(2)), progesterone (P(4)), and its metabolite, 5alpha-pregnan-3alpha-ol-20-one (3alpha,5alpha-THP), in particular, have received much attention for exerting these effects. Typically, it is thought that E(2) precipitates seizures, and progestogens, such as P(4) and 3alpha,5alpha-THP, attenuate seizures. However, E(2) may also have antiseizure effects, perhaps in part through its enhancement of the formation of 3alpha,5alpha-THP, which has GABA(A)/benzodiazepine receptor agonist-like actions. To test this hypothesis, male and female, castrated or ovariectomized, wild-type and 5alpha-reductase knockout mice were implanted with Silastic capsules of E(2) or vehicle and then administered pentylenetetrazol (85 mg/kg, ip). Wild-type, but not 5alpha-reductase knockout, mice administered E(2) had significantly longer latencies to myoclonus and increased levels of 3alpha,5alpha-THP in the hippocampus. Thus, some of the anticonvulsive effects of E(2) may involve formation of 3alpha,5alpha-THP in the hippocampus.

The management of epilepsy in pregnancy

While most women with epilepsy can expect a normal pregnancy outcome, epilepsy remains a significant contributor to both maternal and perinatal morbidity. Pre-pregnancy planning must address reliable contraception and optimisation of antiepileptic drug (AED) regimens to minimise teratogenic risk while maintaining seizure control. The most recent data from the AED registries regarding malformations is presented in this review, as is the limited data on the newer AEDs and studies linking neurocognitive outcomes to AED exposure. During pregnancy, important considerations include; therapeutic drug monitoring, surveillance for obstetric complications and vigilance for seizures during the intrapartum and postpartum period.

Therapeutic product disposition in at-risk populations

In an emergency situation, such as a chemical, biological, radionuclide, nuclear or explosion (CBRNE) event, all patient populations are at increased risk of serious adverse events. Therapeutic product (TP) safety and efficacy depend on the disposition of the product through absorption, distribution, metabolism and excretion. The ability of a patient to benefit from or merely tolerate a TP can be modified by many factors, including but not limited to culture, diet, disease, environmental contaminants, genetic predisposition, stress and socioeconomic status and recent life experiences. Metabolism is considered to have the greatest effect on safety and efficacy, as chemicals not metabolised can accumulate to toxic levels. Inter-individual variances in most drug metabolism enzymes may range up to greater than 1000-fold. The fetus, neonates, infants, individuals with hormonal change, infection or prior exposure to licit or illicit products and the elderly are more susceptible to increased risk of serious adverse health effects. The critically ill are the most at risk. The at-risk populations for a serious adverse event are dependent then on the CBRNE event, their physical and cognitive states and the inter-individual intrinsic and extrinsic factors that affect TP disposition.