Maximizing the health of women with epilepsy: science and ethics in new drug development

Why we urgently need improved epilepsy therapies for adult patients

PURPOSE

Up to a third of patients with epilepsy suffer from recurrent seizures despite therapeutic advances.

RESULTS

Current epilepsy treatments are limited by experiential data from treating different types of epilepsy. For example, we lack evidence-based approaches to efficacious multi-drug therapies or identifying potentially serious or disabling adverse events before medications are initiated. Despite advances in neuroscience and genetics, our understanding of epilepsy pathogenesis and mechanisms of treatment-resistance remains limited. For most patients with epilepsy, precision medicine for improved seizure control and reduced toxicity remains a future goal.

CONCLUSION

A third of epilepsy patients suffer from ongoing seizures and even more suffer from adverse effects of treatment. There is a critical need for more effective and safer therapies for epilepsy patients with frequent comorbitidies, including depression, anxiety, migraine, and cognitive impairments, as well as special populations (e.g., women, elderly). Advances from genomic sequencing techniques may identify new genes and regulatory elements that influence both the depth of the epilepsies' roots within brain circuitry as well as ASD resistance. Improved understanding of epilepsy mechanisms, identification of potential new therapeutic targets, and their assessment in randomized controlled trials are needed to reduce the burden of refractory epilepsy. This article is part of the special issue entitled 'New Epilepsy Therapies for the 21st Century - From Antiseizure Drugs to Prevention, Modification and Cure of Epilepsy'.

Psychosocial adjustment of epilepsy patients in Cyprus

This study investigated aspects of psychosocial adjustment in epilepsy patients in Cyprus. Sixty-three patients under 55 years of age with idiopathic or symptomatic epilepsy and 89 neurologically matched healthy volunteers participated. Subjects completed the State and Trait Anxiety Inventory and the Beck Depression Inventory; patients with epilepsy also completed the Epilepsy Foundation Concerns Index. Results showed that patients with symptomatic epilepsy had significantly higher scores on state and trait anxiety and depressive symptoms. Sociodemographic characteristics including gender, marital status, and education levels contributed to differences in trait and state anxiety, depressive symptom scales, autonomy concerns, and fear for seizure recurrence. Variables such as poor seizure control and use of polytherapy were associated with lower adjustment scores and reduced psychosocial outcome. Finally, patients with epilepsy scored significantly higher on depression and anxiety symptoms. The results provide further evidence on challenges patients with epilepsy face and on the need for implementing psychosocial prevention programs.

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.

Influence of sex hormones on brain excitability and epilepsy

Epilepsy is one of the most common neurologic problems worldwide. In spite of the many studies carried out, our understanding of generalized epileptogenesis remains far from complete. In recent years many data have clarified the effects of sexual hormones on brain excitability. Female and male sexual hormones may be considered pharmacoactive compounds that alter the seizure threshold, changing the frequency and semeiology of the seizures. In particular, estrogens may increase neuronal excitability while progesterone enhances inhibitions and increases the seizure threshold; on the other hand, androgens can decrease ictal activity in the human brain. This review provides an overview of the current knowledge in this field and highlights some of the prevailing hypotheses about the effects of sexual hormones on neuronal excitability analysing data from both animal and clinical studies.

Seizures in the Developing Brain

PURPOSE

Development and sex hormones are important determinants of seizure susceptibility. Seizures develop in the immature brain more readily than in the mature brain. Male children experience a higher incidence of epilepsy or unprovoked seizures than do female children. Sex-specific differences in the development of seizure-suppressing neuronal networks may account, at least in part, for this increased age- and sex-related susceptibility to seizures. The control of seizures can be influenced by the substantia nigra pars reticulata (SNR) in an age- and sex-specific manner. In the adult male rat SNR, two topographically discrete regions (SNRanterior and SNRposterior) mediate distinct effects on seizures, by using divergent output networks in response to localized infusions of gamma-aminobutyric acid (GABA)A agents, such as muscimol. The GABAA-sensitive "anticonvulsant" region is located in the SNRanterior, whereas the GABAA-sensitive "proconvulsant region is in the SNRposterior. In immature postnatal day (PN)15-21 male rats, the SNR is not topographically segregated, and GABAAergic drug infusions produce similar effects when applied in the SNRanterior or SNRposterior. Only a GABAA-sensitive proconvulsant network is evident. By contrast, female SNR does not contain any region that mediates muscimol-related proconvulsant effects. As with the adult, immature female rats do not develop a proconvulsant SNR region at any age.

METHODS

We measured the effects of SNR muscimol infusions on seizures in male rats castrated at birth to better understand the effects of testosterone on the formation of age- and sex-specific features of the SNR.

RESULTS

Neonatal castration permanently alters the maturation of the muscimol-sensitive SNR effect on seizures. The SNR of neonatally castrated rats develops functionally like the "female" SNR. The "proconvulsant" SNR region does not develop in the absence of testosterone in the immediate postnatal period. The "male" type of SNR effects can be induced in neonatally castrated rats by restoration of testosterone levels or in female rats by artificially increasing testosterone levels. Dihydrotestosterone and estrogen, produced by the reduction and aromatization of testosterone, respectively, are the direct mediators of testosterone actions. At PN0, only beta estrogen receptors are equally expressed in the SNRs of males and females and may be responsible for testosterone-mediated effects in both sexes.

CONCLUSIONS

The phenotype of SNR GABAergic neurons, as characterized by GABAA-receptor subunit composition, by muscimol-induced electrophysiologic responses, and by connectivity of output networks each may be altered by the presence of testosterone. Higher KCC2 messenger RNA (mRNA) expression in female PN15 SNR neurons compared with males may be responsible for sex-related differences in muscimol-induced electrophysiologic responses. In summary, a growing body of compelling evidence identifying sex-related differences in the SNR implicates postnatal testosterone as a critical factor in the development of pro- or anticonvulsant circuits. The recognition of sex- and age-related features in the SNR holds the promise that these findings can be translated into the development of specific and effective treatments for seizure disorders.

Gonadal, adrenal, and neuroactive steroids' role in ictal activity

Of the many people that have epilepsy, only about 70% achieve seizure control with traditional pharmacotherapies. Steroids have long been known to influence ictal activity and may have a therapeutic role. This review summarizes recent investigations that have enhanced knowledge of the effects and mechanisms of gonadal, adrenal, and neuroactive steroids on seizure processes. Progesterone, which varies across reproductive cycles, pregnancy, and as a function of aging, has been shown to have anti-seizure effects among women with epilepsy and in animal models of epilepsy. Further, data suggest that progesterone's anti-seizure effects may involve its metabolism to the neuroactive steroid, 5 alpha-pregnan-3 alpha-ol-20-one (3 alpha,5 alpha-THP), and its subsequent actions at GABA(A) receptors. Androgens also have anti-seizure effects. Androgens' anti-seizure effects may be mediated, in part, through actions of the testosterone metabolite, and neuroactive steroid, 5 alpha-androstane-3 alpha,17 alpha-diol (3 alpha-diol) at GABA(A) receptors. Stress can alter seizure susceptibility, suggesting a role of adrenal steroids on seizure processes. In animal models of epilepsy, acute or chronic stress can increase ictal activity. Notably, stress and seizures can alter levels of gonadal, adrenal, and neuroactive steroids, which may then influence subsequent seizure activity. Thus, this review summarizes recent progress in the role of gonadal, adrenal, and/or neuroactive steroids in seizure processes which suggest that greater understanding of these steroids' effects and mechanisms may ultimately lead to improved seizure control for people with epilepsy.

Polycystic ovary syndrome and epilepsy: a review of the evidence

Overrepresentation of polycystic ovary syndrome (PCOS) in women with epilepsy has been described since the early 1980s. While some authors attribute this association to an effect of the seizure disorder on the hypothalamic control of reproductive function, others have reported a relationship with the use of the antiepileptic drug valproic acid (VPA). In this article we review the literature on this complex issue, with a detailed analysis of the different reports which describe the reproductive endocrine assessment in women with epilepsy. In spite of the large number of patients assessed, a clear picture does not emerge, mostly because of the wide variability of methodology employed in the different study projects and of the small size of many patient samples especially when divided in subgroups. However, on the whole these studies suggest that women with epilepsy are at risk for developing reproductive endocrine disorders, even if there is not yet definite evidence that PCOS may be over-represented in these patients nor that VPA may be the cause of endocrine problems. It is likely that both the epileptic disorder and the antiepileptic treatment play different roles in the development of such disturbances. This hypothesis deserves further prospective study in large samples of patients; consistency in methodology, diagnostic criteria and presentation of results should always be encouraged in the researchers dealing with these projects. In the meantime, women with epilepsy should be carefully monitored with regard to menstrual function, bodyweight and hyperandrogenism, and evaluation of these parameters should become part of the routine evaluation in baseline and follow-up consultations.

Trials in women

Women of childbearing age have been viewed as a 'vulnerable population' and have been systematically excluded from early clinical trials. A change in attitude and policies occurred in the last decade, with a consequent increase of women participating in clinical trials. The implications are increasing respect for the woman's capacity to make her own risk-benefit choices, early evaluation of patients that represent the ultimate user of a drug and equal opportunities for women to benefit from the therapeutic potential of new drugs. Drug trials should be designed to identify sex-related effects and to analyse the efficacy and tolerability of antiepileptic drugs (AEDs) by gender. Further aspects should be considered, including changes in response in relation to the menstrual cycle and over the various stages of reproductive life; interactions between hormonal therapies and AEDs; the effect of AEDs on reproductive function and possible consequences of prenatal exposure to AEDs. These considerations become even more critical when pregnant and lactating women are considered, since any risk for the offspring is unacceptable unless drug administration is likely to have major medical benefits for the mother.

Management of epilepsy in adolescents and adults

Epilepsy is the most common serious neurological disorder affecting an estimated 50 million people worldwide. Particular focus should be placed on a safe diagnosis, seizure and syndrome classification, and choice of pharmacological and surgical options for a range of patient populations with different health-care requirements. Eight new antiepileptic drugs were licensed in the 1990s with more to come. These new drugs along with earlier resective surgery have led to a better outcome for many more people with this condition.

Gender-based differences and menstrual cycle-related changes in specific diseases: implications for pharmacotherapy

Pharmacists should be aware of gender-based differences and menstrual cycle-related changes in six diseases: asthma, arthritis, migraine, diabetes, depression, and epilepsy. In general, women report symptoms of physical illness at higher rates, visit physicians more frequently, and make greater use of other health care services than men. Whereas reasons for these gender differences are not fully clear, a combination of biologic, physiologic, social, behavioral, psychologic, and cultural factors most likely contributes. A significant percentage of women with asthma, arthritis, migraine, diabetes, depression, or epilepsy experience worsening of their disease premenstrually. The mechanism is unknown, but is speculated to be multifactorial because of many endogenous and exogenous modulators and mediators of each disease. As part of general therapy for cycle-related exacerbations of any one of these disorders, patients should be encouraged to use a menstrual calendar to track signs and symptoms for two to three cycles; if cyclic trends are identified, the women should anticipate exacerbations and avoid triggering factors. Cyclic modulation with pharmacotherapy may be attempted. If unsuccessful, a trial of medical ovulation suppression with a gonadotropin-releasing hormone (GnRH) analog may be warranted. If that is successful, continuous therapy with a GnRH analog and steroid add-back therapy or less expensive alternatives may be effective. If pharmacotherapy is impractical, hysterectomy and bilateral oophorectomy with estrogen replacement therapy is a last resort. Gender differences and menstrual cycle-related changes are important areas for clinical and mechanistic research.

Is valproate pharmacotherapy associated with polycystic ovaries?

OBJECTIVE

To review and evaluate the published data associating the use of valproate with the development of polycystic ovaries.

DATA SOURCES

A computerized search of MEDLINE (1966-May 1999) and Current Contents was performed. Also, bibliographies were cross-referenced to yield additional pertinent publications. All articles written in English were considered for review.

STUDY SELECTION AND DATA EXTRACTION

All pertinent clinical studies and review articles associating valproate with polycystic ovaries and other endocrinologic disorders were evaluated.

DATA SYNTHESIS

Valproate is among the most commonly used medications today effective in the treatment of a variety of neurologic and psychiatric disorders. An accumulating body of literature has suggested an increase in the incidence of polycystic ovarian syndrome among women treated with valproate. The syndrome is characterized as hyperandrogenism and chronic anovulation in the absence of identifiable adrenal or pituitary pathology. It is a highly prevalent syndrome, affecting 2-22% of women in the general population.

CONCLUSIONS

Although a number of studies have found clear evidence of neuroendocrine perturbations in patients treated with valproate, there are presently limited data from large controlled studies involving valproate monotherapy. Nonetheless, there appears to be a greater incidence of polycystic ovaries associated with valproate use in comparison with other anticonvulsants. The mechanism by which valproate may induce polycystic ovarian syndrome is unknown, but could possibly be secondary to valproate-induced weight gain or direct interference with steroid metabolism. Further study of the potential association of valproate treatment with the development of polycystic ovarian syndrome is warranted. Until the issue is clarified, clinicians should at least be aware of the possibility of valproate-induced polycystic ovarian syndrome and monitor patients accordingly.

Effects of epilepsy on women's reproductive health

Reproductive dysfunctions are common and wide-ranging in women with epilepsy. Menstrual cycle disruption, anovulatory cycles, disturbances in hypothalamic and/or pituitary hormones, and disturbances in gonadal steroids are more common among women with epilepsy. Sexual dysfunction can present as either disorders of desire or physiologic arousal, but the most common dysfunction appears to be an inadequate initial physiologic arousal response. Reproductive dysfunctions may be due to psychologic, pharmacologic, or physiologic factors. Physicians should routinely question all women with epilepsy regarding their reproductive and sexual health. A full history, a complete physical, and laboratory evaluations with endocrinologic work-up should be performed in any woman who reports a reproductive dysfunction. Treatment and/or referral to a gynecologist or endocrinologist should be initiated as appropriate.

Women's issues in the treatment of epilepsy

BACKGROUND

The management of women with epilepsy involves a number of important issues including conception control, sexual dysfunction and fertility, the effect of seizures on the fetus, possible changes in seizures frequency during pregnancy, potential teratogenic effects of antiepileptic drugs and management issues during pregnancy. The primary goal in the treatment of women with epilepsy remains optimal seizure control in the absence of unacceptable adverse effects. The advantages and disadvantages of the new antiepileptic drugs in women remain to be fully established but these new agents allow a wider choice for improved seizure control.

Don't test, do sell: legal implications of inclusion and exclusion of women in clinical drug trials

This article explores the historic underpinnings of the exclusion of women from clinical drug trials, identifies recent developments, and examines legal implications for women with epilepsy and for others. Distinguishing stakeholders and their interests may lead to policies that better serve all. Past and present statutory, regulatory, and judicial frameworks were reviewed, as well as legal, medical, and historical commentary. Traditionally, researchers and manufacturers have not tested particular drugs on women. Physicians and pharmacists routinely prescribe and sell these same medications regardless of gender. Only since 1993 have females been more likely to be included in clinical drug trial subject pools. The impact of past and future practices on health care provision and legal liability remains unknown. A policy of "Don't test, do sell" will not protect women with epilepsy or would-be defendants. At this time the most effective shields will involve procurement of informed consent as well as testing of both women and men. In the long run, tort, health care, and regulatory reform will best serve all interested persons. Inclusion of women in clinical drug trials has become a how question, not an if one.