Low-dose sodium valproate in the treatment of idiopathic generalized epilepsies

Predictors of Seizure Recurrence in Women With Idiopathic Generalized Epilepsy Who Switch From Valproate to Another Medication

BACKGROUND AND OBJECTIVES

To investigate the predictors of seizure recurrence in women of childbearing age with idiopathic generalized epilepsy (IGE) who switched from valproate (VPA) to alternative antiseizure medications (ASMs) and compare the effectiveness of levetiracetam (LEV) and lamotrigine (LTG) as VPA alternatives after switch.

METHODS

This multicenter retrospective study included women of childbearing age diagnosed with IGE from 16 epilepsy centers. Study outcomes included worsening or recurrence of generalized tonic-clonic seizure (GTCS) at 12 months and 24 months after the switch from VPA to an alternative ASM. The comparative effectiveness of LEV and LTG as alternative ASM following VPA discontinuation was assessed through inverse probability treatment-weighted (IPTW) Cox regression analysis.

RESULTS

We included 426 women with IGE, with a median (interquartile range) age at VPA switch of 24 (19-30) years and a median VPA dosage of 750 (500-1,000) mg/d. The most common reason for VPA switch was teratogenicity concern in 249 women (58.6%), and the most common ASM used in place of VPA was LEV in 197 (46.2%) cases, followed by LTG in 140 (32.9%). GTCS worsening/recurrence occurred in 105 (24.6%) and 139 (32.6%) women at 12 and 24 months, respectively. Catamenial worsening of seizures, higher VPA dosage during switch, multiple seizure types, and shorter duration of GTCS freedom before switch were independent predictors of GTCS recurrence or worsening at 12 months according to mixed multivariable logistic regression analysis. After internal-external validation through 16 independent cohorts, the model showed an area under the curve of 0.71 (95% CI 0.64-0.77). In the subgroup of 337 women who switched to LEV or LTG, IPTW Cox regression analysis showed that LEV was associated with a reduced risk of GTCS worsening or recurrence compared with LTG (adjusted hazard ratio 0.59, 95% CI 0.40-0.87, p = 0.008) during the 24-month follow-up.

DISCUSSION

Our findings can have practical implications for optimizing counselling and treatment choices in women of childbearing age with IGE and may help clinicians in making informed treatment decisions in this special population of patients.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that for women with IGE switching from VPA, LEV was associated with a reduced risk of GTCS worsening or recurrence compared with LTG.

Effect of a Declined Plasma Concentration of Valproic Acid Induced by Meropenem on the Antiepileptic Efficacy of Valproic Acid

OBJECTIVE

This study aimed to indicate whether a declined plasma concentration of valproic acid (VPA) induced by co-administration of meropenem (MEPM) could affect the antiepileptic efficacy of VPA.

METHODS

We retrospectively reviewed data of hospitalized patients who were diagnosed with status epilepticus or epilepsy between 2010 and 2019. Patients co-administered VPA and MEPM during hospitalization were screened and assigned to the exposure group, while those co-administerd VPA and other broad-spectrum antibiotics were allocated to the control group.

RESULTS

The exposure group and control group included 50 and 11 patients, respectively. With a similar dosage of VPA, the plasma concentration of VPA significantly decreased during co-administration (24.6 ± 4.3 μg/mL) compared with that before co-administration (88.8 ± 13.6 μg/mL, p < 0.0001), and it was partly recovered with the termination of co-administration (39.8 ± 13.2 μg/mL, p = 0.163) in the exposure group. The inverse probability of treatment weighting estimated the treatment efficacy via changes in seizure frequency, seizure duration, and concomitant use of antiepileptic drugs, which were not significantly different between the exposure and control groups. In the exposure group, there was no significant differences in seizure frequency between the periods of before-during and before-after (p = 0.074 and 0.153, respectively). Seizure duration during VPA-MEPM co-administration was not significantly different from that before co-administration (p = 0.291).

CONCLUSIONS

In this study, the reduced plasma concentration of VPA induced by the co-administration of MEPM did not affect the antiepileptic efficacy of VPA. This conclusion should be interpreted with caution, and more research is warranted.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR2000034567. Registered on 10 July 2020.

Minimum effective sodium valproate dose in genetic generalized epilepsies

INTRODUCTION

Sodium valproate (VPA) is the most effective antiseizure medication (ASM) in genetic generalized epilepsies (GGEs). However, the frequent adverse effects and the high risk inflicted on the exposed offspring make it imperative to search for the lowest daily VPA dose able to control seizures for most patients. In the current published series, the VPA value of <1000 mg was the most adopted.

OBJECTIVE

This study aims to provide a cutoff VPA value below which a given daily dose can be considered a low dose in patients with GGEs.

METHODS

This retrospective, observational cohort study included patients with clinical and electroencephalographic diagnoses of GGEs based on the ILAE criteria. Patients were followed up for at least two years using VPA in mono- or polytherapy. Clinical data, VPA dose, and associated ASMs were analyzed. Adverse effects were also evaluated. We related seizure control to VPA doses through uni- and multivariate statistical analyses.

RESULTS

From 225 patients, 169 (75%) had good seizure control, with most (60%) receiving monotherapy. The cutoff daily VPA dose capable of distinguishing these patients from those without seizure control was up to 1000 mg (p = 0.006) in univariate analyses and up to 700 mg in multivariate analyses. For patients in polytherapy, the cutoff was up to 1750 mg and 1800 mg in uni- and multivariate analyses, respectively.

CONCLUSIONS

The lowest daily VPA dose in monotherapy able to control seizures for most GGE patients was up to 700 mg, a value that can be used as a low dose criterion in studies assessing the therapeutic VPA ranges. Patients using higher VPA doses or in polytherapy present a lower probability of seizure control.

Genetic generalized epilepsy: factors associated with drug resistance polytherapy

Background

Different studies investigating generalized genetic epilepsy (GGE) have shown that achieving 5 years of remission, early seizure remission, and needing antiseizure medication (ASM) monotherapy may predict favorable long-term outcomes.

Results

This is a retrospective analytical cohort study. Records of patients with GGE diagnoses at a large epilepsy center in Cairo served as the data source. 630 patients (297 male patients (47.1%) and 333 female (52.9%)) were included, their median onset age was 13 years. The follow-up period of this study was at least 4 years. 418 patients (66.1%) were early remitters, 160 patients (25.4%) were late remitters, and 52 patients (8.3%) were intractable. In addition, 367 patients (58.3%) needed a single ASM to achieve a maximum remission period (monotherapy group), while 263 patients (41.7%) needed ASM polytherapy. Stepwise regression analysis revealed that absence seizures, clusters of seizures, seizure frequency before treatment, and dose of sodium valproate (VPA) until the first remission were independent predictors for polytherapy. Moreover, absence seizures, seizure frequency before treatment, VPA dose, and catamenial seizures in females were independent predictors of intractability.

Conclusion

The majority of GGE have a favorable outcome, some clinical features could predict the need for polytherapy and failure of remission on treatment.

Movement disorders associated with antiseizure medications: A systematic review

New-onset movement disorders have been frequently reported in association with the use of antiseizure medications (ASMs). The frequency of specific motor manifestations and the spectrum of their semiology for various ASMs have not been well characterized. We carried out a systematic review of literature and conducted a search on CINAHL, Cochrane Library, EMBASE, MEDLINE, PsycINFO, and Scopus from inception to April 2021. We compiled the data for all currently available ASMs using the conventional terminology of movement disorders. Among 5123 manuscripts identified by the search, 437 met the inclusion criteria. The largest number of reports of abnormal movements were in association with phenobarbital, valproic acid, lacosamide, and perampanel, and predominantly included tremor and ataxia. The majority of attempted interventions for all agents were discontinuation of the offending drug or dose reduction which led to the resolution of symptoms in most patients. Familiarity with the movement disorder phenomenology previously encountered in relation with specific ASMs facilitates early recognition of adverse effects and timely institution of targeted interventions.

Genetic generalized epilepsies in adults - challenging assumptions and dogmas

Genetic generalized epilepsy (GGE) syndromes start during childhood or adolescence, and four commonly persist into adulthood, making up 15-20% of all cases of epilepsy in adults. These four GGE syndromes are childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy and epilepsy with generalized tonic-clonic seizures alone. However, in ~20% of patients with GGE, characteristics of more than one syndrome are present. Novel insights into the genetic aetiology, comorbidities and prognosis of the GGE syndromes have emerged and challenge traditional concepts about these conditions. Evidence has shown that the mode of inheritance in GGE is mostly polygenic. Neuropsychological and imaging studies indicate similar abnormalities in unaffected relatives of patients with GGE, supporting the concept that underlying alterations in bilateral frontothalamocortical networks are genetically determined. Contrary to popular belief, first-line anti-seizure medication often fails to provide seizure freedom in combination with good tolerability. Nevertheless, long-term follow-up studies have shown that with advancing age, many patients can discontinue their anti-seizure medication without seizure relapses. Several outcome predictors have been identified, but prognosis across the syndromes is more homogeneous than previously assumed. Overall, overlap in pathophysiology, seizure types, treatment responses and outcomes support the idea that GGEs are not separate nosological entities but represent a neurobiological continuum.

Predictors of successful valproate withdrawal in women with epilepsy

OBJECTIVE

Valproate (VPA) use was restricted due to its teratogenic risks in women with epilepsy (WWE). We aimed to assess the outcome and predictors of treatment decisions of withdrawal/switch or continuation of VPA in WWE.

METHODS

We included 214 consecutive WWE with a follow-up time of 9.57 ± 7.04 years, who have used (n = 142) or are still using VPA (n = 72) during their reproductive ages. The demographic, clinical, and electroencephalography (EEG) properties of WWE who could withdraw (successful withdrawal; n = 142) and could not withdraw VPA (unsuccessful withdrawal; n = 36) were compared statistically.

RESULTS

The main reasons for still using VPA were high risk of seizure recurrence (63.9%), cognitive impairment (27.8%), and no pregnancy prospect (8.3%). In the successful withdrawal group, 67 (47.1%) patients maintained remission after VPA withdrawal and 26 of them (38.8%) had relapse during the follow-up. The rate of side effects related to the new drugs (levetiracetam and lamotrigine) was 52/142 (36.6%). The unsuccessful withdrawal rate was 13.9% in focal epilepsy whereas it was 86.1% in generalized epilepsy (p = 0.002). Co-occurrence of three types of seizures and anti-seizure medication (ASM)-resistance was related to unsuccessful withdrawal in genetic generalized epilepsy (GGE) (p = 0.02 for both).

CONCLUSIONS

Although women with focal epilepsies are more ASM-resistant and more likely to have continuing seizures, they do not usually deteriorate after VPA discontinuation, therefore posing them to teratogenic risk is often unnecessary. In GGE, certain predictors such as previous ASM-resistance and the presence of three seizure types must be taken into account, before a withdrawal attempt of VPA treatment.

Cosmetic adverse effects of antiseizure medications; A systematic review

BACKGROUND

We systematically reviewed the existing literature on the cosmetic adverse effects of antiseizure medications (ASMs) in order to depict a clear picture of these unwanted side effects of ASMs with a particular attention to hair loss, hirsutism, acne, and gingival hyperplasia.

METHODS

This systematic review was prepared according to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Scopus, MEDLINE, and Google Scholar from the inception to 25 March, 2021 were systematically searched. These key words (title/abstract) were used: "hair loss" OR "hirsutism" OR "acne" OR "gingival hyperplasia" AND "seizure" OR "epilepsy" OR "anriseizure" OR "antiepileptic". The exclusion criteria included: non-original studies, articles not in English, and animal studies.

RESULTS

The primary search yielded 3938 studies; 127 studies were related to the topic and were included in the current systematic review. The most robust evidence on cosmetic adverse effects of ASMs were related to phenytoin (causing gingival hyperplasia, hirsutism, and acne) and valproate (causing hair loss and hirsutism); however, many other ASMs were also implicated in causing these cosmetic adverse effects.

CONCLUSION

Antiseizure medications may be associated with various cosmetic adverse effects. Phenytoin and valproate are the most notorious ASMs in this regard; but, other ASMs have also been implicated in causing hair loss, hirsutism, acne, and gingival hyperplasia. Physicians should pay more attention to these significant adverse effects that may affect a patient's facial attractiveness, quality of life, and emotional state.

Experience with Low-Dose Sodium Valproate in Idiopathic Generalized Epilepsy Patients: A Long-Term Follow-Up Study on Selective Cohort from North India

Background  Idiopathic generalized epilepsy (IGE) is found in 20 to 30% of all patients presenting with seizures. Most of the patients require lifelong drug treatment. Efficacy and tolerability are important issues while selecting the most appropriate drug for a person with IGE. Objective  The aim of this study was to look for usefulness of small dose valproate (<1,000 mg/day) in long-term treatment of IGE patients. Methods  Diagnosis of IGE made with standard criteria among all patients presenting with seizures. Patients put on full doses of valproate (>1,000 mg/day) in first year, then reduction started in next year in patients with full seizure remission, and finally maintained on lowest possible dose of valproate. Lowest dose was defined as the minimum dose without seizures (between 200 and 900 mg/day). Patients, who were refractory on monotherapy, were put on add-on drug and followed for remission and reduction in doses of valproate at minimum possible dose. Results  IGE was diagnosed in 21% of all patients presenting with seizures. Among 420 patients of IGE 368 (87.5%) were started on high-dose valproate monotherapy, 155 (42.1%) were responsive to single drug while 213 (57.9%) had been given add-on drug either lamotrigine or clonazepam or both. After minimum 3-year follow-up, 298 (81%) could be managed on low-dose valproate (<1,000 mg) without any relapse during 12 to 80 months follow-up. Conclusion  Significant number of patients with IGE can be managed on low-dose valproate with good seizure control and less side effects.

Expert opinion: use of valproate in girls and women of childbearing potential with epilepsy: recommendations and alternatives based on a review of the literature and clinical experience-a European perspective

Valproate is a broad-spectrum antiepileptic drug (AED) of particular interest in pediatric epilepsy syndromes and idiopathic generalized epilepsy, as it is relatively more effective in these syndromes than other AEDs. In 2018, the European Medicines Agency introduced new restrictions on the use of valproate in girls and women of childbearing potential to avoid exposure during pregnancy. The strengthening of existing restrictions sparked controversy and debate among patients and the medical community. The high prevalence of epilepsy syndromes amenable to valproate treatment in women of childbearing age and the little information available on the teratogenic potential of alternative treatments have created uncertainty on how to manage these patients. In this consensus statement, based on a review of the literature and the clinical experience of a panel of European epilepsy experts, we present general recommendations for the optimal clinical management of AED treatment in girls, women of childbearing potential, and pregnant women across the different epilepsy syndromes.

Factors Associated with Good Seizure Control in Patients on Valproic Acid

Objective

This study aims to generate a reference range for valproic acid (VPA) in this cohort and determine the factors associated with good seizure control in patients taking this drug.

Materials and Methods

We conducted a prospective, cohort, observational study among patients with epilepsy who received VPA treatment at Hospital Kuala Lumpur. The patients were considered to have good control if they had a 50% or higher seizure reduction in the one-year study period compared with the previous year. The VPA reference range was generated from those patients who had good control and whose drug concentration values were available. Multiple logistic regression analysis with a backward likelihood ratio method was applied to assess the predicting factors for good seizure control.

Results

A total of 242 patients were recruited and followed up for one year. The VPA reference range was determined to be 40-85 mg/L. After multivariate analysis, significant predictive variables for good control were monotherapy [adjusted OR 4.74, 95% CI: 2.258, 9.947, p<0.001], non-smoking [adjusted OR 3.23, 95% CI: 1.099, 9.473, p=0.033], normal brain imaging results [adjusted OR 5.83, 95% CI: 2.507, 13.552, p<0.001], and the absence of stress [adjusted OR 19.98, 95% CI: 9.255, 42.764, p<0.001].

Conclusion

Monotherapy, non-smoking, normal brain imaging results, and the absence of stress are predictive of good seizure control in patients on VPA. However, a serum concentration of VPA in the reference range failed to predict good seizure control.

Outcomes of low-dose valproic acid treatment in patients with juvenile myoclonic epilepsy

PURPOSE

There are conflicting data regarding the drug dose that is sufficient to achieve seizure control as well as the parameters of seizure remission in juvenile myoclonic epilepsy (JME). The present study aimed to identify factors that contribute to seizure control in JME and to evaluate factors associated with JME remission and the efficacy of low-dose valproic acid (VPA) therapy.

METHODS

This retrospective, cross-sectional study included a total of 215 patients (121 female and 94 male; mean age: 28.03 ± 8.43 [14-59] years) diagnosed with JME. The patients were divided into remission and refractory groups. Remission was defined as a seizure-free (myoclonic, absence, and/or generalized tonic-clonic) period of at least 2 years. Patients in whom remission was achieved with VPA monotherapy were further divided into two groups according to the use of low-dose VPA therapy (VPA ≤ 750 mg/day and >750 mg/day). Potential contributing factors were evaluated in terms of the relationship between the dose and the remission parameters.

RESULTS

Remission was achieved with VPA monotherapy in 116 patients (87.9%) in the remission group; the VPA dose was ≤750 mg in 77.6% of the patients. The dose of VPA was higher in patients with absence seizure who achieved remission (p = 0.026). Remission was achieved with a lower dose of VPA in females than in males (p = 0.004).

CONCLUSIONS

Low-dose VPA can be used to achieve remission in JME. However, identification at follow-up visits of the factors that may affect remission may change the planned effective dose of VPA.

High-dose versus low-dose valproate for the treatment of juvenile myoclonic epilepsy: Going from low to high

Juvenile myoclonic epilepsy (JME) is a genetic generalized epilepsy accounting for 3-12% of adult cases of epilepsy. Valproate has proven to be the first-choice drug in JME for controlling the most common seizure types: myoclonic, absence, and generalized tonic-clonic (GTC). In this retrospective study, we analyzed seizure outcome in patients with JME using valproate monotherapy for a minimum period of one year. Low valproate dose was considered to be 1000mg/day or lower, while serum levels were considered to be low if they were at or below 50mcg/dl. One hundred three patients met the inclusion criteria. Fifty-six patients (54.4%) were female. The current average age was 28.4±7.4years, while the age of epilepsy onset was 13.6±2.9years. Most patients corresponded to the subsyndrome of classic JME. Forty-six (44.7%) patients were free from all seizure types, and 76 (73.7%) patients were free from GTC seizures. No significant difference was found in seizure freedom among patients using a low dose of valproate versus a high dose (p=0.535) or among patients with low blood levels versus high blood levels (p=0.69). In patients with JME, it seems appropriate to use low doses of valproate (500mg to 1000mg) for initial treatment and then to determine if freedom from seizures was attained.