Assessing risk to benefit ratio in antiepileptic drug therapy

Protective effect of Grewia asiatica leaves extract in animal models of epilepsy and anxiety

Grewia asiatica Linn. is a well-known plant for its nutritional and therapeutic attributes. It has been mentioned in ancient Indian literature as Rasayana due to its stimulant and tonic effects. Thus, present investigation was carried out to evaluate the antiepileptic and anxiolytic action of G. asiatica Linn. leaves using animal models. Methanol extract at dose levels of 100 and 200 mg/kg was capable of providing protection against both pentylenetetrazole and maximal electroshock induced seizures in mice. Extract also showed significant anxiolytic activity in elevated plus maze, light/dark box and mirror chamber mice models at same dose levels. Results of this study indicated that the methanol extract of leaves of G. asiatica plant possess significant antiepileptic and anxiolytic effect.

Carbamazepine-Induced Hematological and Immunological Alterations in Egyptian Children with Idiopathic Generalized Seizures

Carbamazepine (CBZ) is one of the oldest antiepileptic drugs (AEDs) that is still used for the treatment of tonic-clonic seizures in children. Long-term use of AEDs induces potential toxic effects that may remain undetermined for a long time. Earlier studies have revealed a wide spectrum of hematological toxicities associated with CBZ. This study was conducted to unveil the toxic effects of carbamazepine as an antiepileptic monotherapy on hematological and immunological parameters in a group of Egyptian pediatric patients using it for different durations. Fifty pediatric epileptics of either sex were enrolled; 38 were taking CBZ as antiepileptic monotherapy for ≥ 6 months and 12 were newly diagnosed untreated patients. Hematological and immunological parameters studied were compared with their age and sex-matched 15 controls and among groups. CBZ was found more toxic for total leukocyte count, lymphocyte count, serum IgA and IgM levels (p < 0.001, 0.001, < 0.001, < 0.001, respectively). Hemoglobin level, platelets count, serum C4 level and IgA were negatively correlated with serum CBZ level (Spearman's rho = – 0.62, – 0.42, – 0.34, – 0.13; p < 0.001, 0.008, 0.04, 0.44, respectively). CBZ treatment duration associated inversely with platelets, lymphocyte, and eosinophil counts (p < 0.001, 0.03, 0.01, respectively). Epileptic children on CBZ monotherapy had their hematologic and immunologic systems affected, which mandates routine monitoring of these children.

Cerebellar Degeneration in Epilepsy: A Systematic Review

Introduction: Cerebellar degeneration has been associated in patients with epilepsy, though the exact pathogenic mechanisms are not understood. The aim of this systematic review was to identify the prevalence of cerebellar degeneration in patients with epilepsy and identify any pathogenic mechanisms. Methodology: A systematic computer-based literature search was conducted using the PubMed database. Data extracted included prevalence, clinical, neuroradiological, and neuropathological characteristics of patients with epilepsy and cerebellar degeneration. Results: We identified three consistent predictors of cerebellar degeneration in the context of epilepsy in our review: temporal lobe epilepsy, poor seizure control, and phenytoin as the treatment modality. Whole brain and hippocampal atrophy were also identified in patients with epilepsy. Conclusions: Cerebellar degeneration is prevalent in patients with epilepsy. Further prospective studies are required to confirm if the predictors identified in this review are indeed linked to cerebellar degeneration and to establish the pathogenic mechanisms that result in cerebellar insult.

Changes in drug load during lacosamide combination therapy: A noninterventional, observational study in German and Austrian clinical practice

Introduction

Effects of antiepileptic drug (AED) load changes in patients with focal seizures have not been well evaluated.

Methods

SP1065 (NCT01673282) was a noninterventional, prospective, observational study conducted in a clinical practice setting. Patients (aged ≥18 years) with focal seizures were enrolled within 7 days of being prescribed adjunctive lacosamide. Observation period was ~6 months. Drug load was assessed using percentage change in ratio of actual prescribed dose and World Health Organization defined daily dose (DDD) for concomitant AEDs and all AEDs (including lacosamide). Subgroups were defined for patients with at least one concomitant sodium channel–blocking AED (SCB [+]) and those without (SCB [−]).

Results

A total of 311 patients were assessed for safety, 302 for measurement of drug load, and 240 for effectiveness. Ratio of AED dose to DDD decreased for concomitant AEDs (−9.6%) and increased for all AEDs (including lacosamide; 15.5%). Median reduction in focal seizure frequency per 28 days was 100% (range: −100, 2275.8). 70.4% and 61.7% of patients had a ≥50% or ≥75% reduction in seizure frequency, respectively; 50.8% became seizure‐free. In the SCB (+) subgroup (n = 149), ratio of AED dose to DDD decreased for concomitant AEDs (−15.0%) and increased for all AEDs (10.7%). In the SCB (−) subgroup (n = 153), ratio of AED dose to DDD decreased for concomitant AEDs (−4.4%) and increased for all AEDs (20.2%). Fifty‐seven patients (18.3%) reported ADRs, most commonly dose >400 mg/d (7.1%). Seventeen patients (5.5%) had ADRs leading to discontinuation.

Significance

Addition of lacosamide resulted in reduction of concomitant AED drug load regardless of whether concomitant AEDs were SCB (+) or SCB (−). These results indicate that addition of lacosamide in patients with focal seizures could allow clinicians to withdraw or reduce the dose of less well‐tolerated or less effective AEDs.

Clinical opinion: Earlier employment of polytherapy in sequential pharmacotherapy of epilepsy

Modern pharmacotherapy for epilepsy consists of orderly, sequential drug trials, in which antiepileptic drugs (AEDs) are chosen under the concept of individual patient-oriented (or - tailored) pharmacotherapy. Although monotherapy has been established as the preferred mode of AEDs therapy in both newly diagnosed and drug resistant epilepsies, there are still lack of evidence to favor either monotherapy or polytherapy in epilepsy, which has generated continuing controversies on the preferred mode of pharmacotherapy. However, each mode of pharmacotherapy may have both advantages and disadvantages, which are different and variable related to individual case scenario. We conducted a brief comparative overview between monotherapy and polytherapy to provide clues for earlier employment of polytherapy in each steps of sequential drug trials. Previous claims about the advantages of monotherapy over polytherapy are not supported but gradually losing its ground by the introduction of a large number of drugs carrying pharmacological advantages for combination therapy. Current evidence stresses the importance of combining drugs having synergistic interactions for better outcome of polytherapy, which has not been considered in previous clinical investigations comparing monotherapy and polytherapy. It is likely that a significant improvement in the outcome of current AEDs therapy is feasible by earlier employment of polytherapy as well as identification of combination drug regimens carrying synergistic interactions. At present, lamotrigine(LTG) and valproate(VPA) combination regimen is the only well documented synergistic regimen, but there are a long-list of candidate regimens requiring future trials in appropriate designs.

Comparative efficacy of antiepileptic drugs for patients with generalized epileptic seizures: systematic review and network meta-analyses

Background Valproate is a widely prescribed antiepileptic drug for generalized epilepsies, due to the extensive knowledge on its efficacy since it is on the market for many decades. However, a large number of new antiepileptic medicines was introduced into clinical practice and may be better options for treatment, considering that these medicines differ in terms of efficacy spectrum. Despite extensive research, questions regarding which medicine would constitute the first option for the monotherapy treatment of generalized epilepsy remain. Aim of the Review To compare the relative efficacy of all available antiepileptic drugs in the monotherapy treatment of generalized epileptic seizures; and also to compare all antiepoileptig drugs with valproate, which is the current first-line treatment for generalized epilepsy. Methods A systematic review for randomized controlled clinical trials was performed. Network meta-analyses used Bayesian random effects model. Sensitivity analyses determined the results´ robustness. The relative probability of two efficacy outcomes ("Seizure free" and "Therapeutic inefficacy") to happen for each medcicine was calculated using the Surface Under the Cumulative Ranking Curve. Results Seven papers (1809 patients) studied the efficacy of valproate, lamotrigine, phenytoin, carbamazepine, topiramate, levetiracetam, and phenobarbital in the treatment of generalized tonicclonic, tonic, and clonic seizures. Phenytoin demonstrated to be inferior to valproate in leaving the patient free of these seizures types [OR: 0.50 (95% CrI 0.27, 0.87)]. Lamotrigine (61%) showed the highest probability of presenting the outcome "Seizure free", followed by levetiracetam (47%), topiramate (44%), and valproate (38%) in the treatment of generalized tonic-clonic, tonic, and clonic seizures. Meanwhile, valproate exhibited greater chance of presenting the outcome "Therapeutic inefficacy" (62%). Regarding absence seizures itself, there was no difference in the efficacy of lamotrigine and ethosuximide when compared to valproate. However, the ranking indicates that ethosuximide (52%) and valproate (47%) are both more likely than lamotrigine to keep the patient free of seizures. Conclusions Lamotrigine, levetiracetam, and topiramate are as effective as valproate for treating generalized tonic-clonic, tonic, and clonic seizures. Meanwhile, valproate and ethosuximide are the best options for the treatment of absence seizures promoting better control of seizures, which is the primary goal of pharmacotherapy.

Efficacy and Tolerability of Antiepileptic Drugs in Patients with Focal Epilepsy: Systematic Review and Network Meta-analyses

Several newer antiepileptic drugs (AEDs) have been introduced into clinical practice, offering choices for individualizing the treatment of epilepsy since AEDs have different efficacy and tolerability profiles. In particular, questions exist regarding which AEDs are the best options for the monotherapy of focal epilepsy. Is carbamazepine (CBZ), which is considered the standard treatment for focal epilepsy, still the best option for monotherapy of focal epilepsy, despite the emergence of new AEDs? In this systematic review, we compared the relative tolerability of all available AEDs for monotherapy of all types of epilepsy as well as their efficacy in the monotherapy of focal epilepsy. In addition, we compared CBZ with other AEDs for the monotherapy of focal epilepsy. We performed a search of the MEDLINE/PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials (CENTRAL) databases for randomized controlled clinical trials. To compare the relative efficacy and tolerability of the AEDs, we performed network meta-analyses using a Bayesian random-effects model. Sensitivity analyses were conducted to determine the robustness of the results. A total of 65 studies were included in this review, composing 16,025 patients. Clobazam, levetiracetam, lamotrigine, oxcarbazepine, sulthiame, topiramate, and valproate had the best efficacy profiles and demonstrated no evidence of superiority or inferiority compared with CBZ. However, CBZ showed the greatest risk of patient discontinuation due to intolerable adverse reactions, whereas lamotrigine had the best safety profile and an 81% probability of being the best for the tolerability outcome of patient withdrawals from the study due to intolerable adverse reactions, followed by sulthiame (60%) and clobazam (51%). The newer AEDs-levetiracetam, lamotrigine, oxcarbazepine, sulthiame, and topiramate-should be considered for monotherapy of focal epilepsy because they were demonstrated to be as effective as the older ones (CBZ, clobazam, and valproate) for the treatment of focal epilepsy and were more tolerable. Lamotrigine was the AED with the best tolerability profile, suggesting that it may be the best option for the treatment of focal epilepsy in children and adults.

Efficacy and tolerability of anti-epileptic drugs-an internet study

OBJECTIVE

To ascertain efficacy and tolerability of carbamazepine (CBZ), sodium valproate (VPA), lamotrigine (LTG) and levetiracetam (LEV) using the UKAED register (www.ukaed.info).

METHODS

Patients on CBZ (n=91), VPA (n=61), LTG (n=105), LEV (n=72) and healthy control subjects (CTR) on no medication (n=51) were extracted. All patients had anonymously provided information on seizure type and frequency and completed the Liverpool Adverse Event Profile (LAEP).

RESULTS

The number of seizure-free patients in the last 4 weeks was overall CBZ/VPA/LTG/LEV=60%/79%/67%/67%, for generalized epilepsy was CBZ/VPA/LTG/LEV=67%/89%/65%/94%, and for localization-related epilepsy was CBZ/VPA/LTG/LEV=59%/71%/67%/57%. Mean LAEP scores were CBZ/VPA/LTG/LEV/CTR=42.21/39.66/39.86/43.01/29.69. The mean LAEP was significantly higher in patients reporting depression and in patients with active epilepsy than in patients without depression and remission. Central nervous system (CNS) adverse effects including memory problems, difficulty concentrating, depression, unsteadiness, restlessness, feelings of anger, shaky hands and dizziness were significantly more frequent in CBZ, VPA, LTG and LEV than in CTR. The feeling of anger was significantly more frequent in LEV, and depression was significantly more frequent in CBZ compared to the other drugs.

CONCLUSION

In this Internet-based register of self-reported efficacy and tolerability, CBZ, VPA, LTG and LEV were similar. Self-reported CNS adverse effects were significantly more frequent than in controls. In addition, anger was associated with LEV and depression with CBZ. Confounding factors were depression and uncontrolled epilepsy.

Sex and age differences in the expression of liver microRNAs during the life span of F344 rats

Background

Physiological factors such as age and sex have been shown to be risk factors for adverse effects in the liver, including liver diseases and drug-induced liver injury. Previously, we have reported age- and sex-related significant differences in hepatic basal gene expression in rats during the life span that may be related to susceptibility to such adverse effects. However, the underlying mechanisms of the gene expression changes were not fully understood. In recent years, increasing evidence for epigenetic mechanisms of gene regulation has fueled interest in the role of microRNAs (miRNAs) in toxicogenomics and biomarker discovery. We therefore proposed that significant age and sex differences exist in baseline liver miRNA expression, and that comprehensive profiling of miRNAs will provide insights into the epigenetic regulation of gene expression in rat liver.

Methods

To address this, liver tissues from male and female F344 rats were examined at 2, 5, 6, 8, 15, 21, 52, 78, and 104 weeks of age for the expression of 677 unique miRNAs. Following data processing, predictive pathway analysis was performed on selected miRNAs that exhibited prominent age and/or sex differences in expression.

Results

Of the 314 miRNAs found to be expressed, 214 were differentially expressed; 65 and 212 miRNAs showed significant (false discovery rate (FDR) <5% and ≥1.5-fold change) sex- and age-related differences in expression, respectively. Thirty-eight miRNAs showed 2-week-specific expression, of which 31 miRNAs were found to be encoded within the Dlk1-Dio3 cluster located on chromosome 6. This cluster has been associated with tissue proliferation and differentiation, and liver energy homeostasis in postnatal development. Predictive pathway analysis linked sex-biased miRNA expression with sexually dimorphic molecular functions and toxicological functions that may reflect sex differences in hepatic physiology and disease. The expression of miRNAs (miR-18a, miR-99a, and miR-203, miR-451) was also found to associate with specific sexually dimorphic hepatic histopathology. The expression of miRNAs involved in regulating cell death, cell proliferation, and cell cycle was found to change as the rats matured from adult to old age.

Conclusions

Overall, significant age- and sex-related differences in liver miRNA expression were identified and linked to histopathological findings and predicted functional pathways that may underlie susceptibilities to liver toxicity and disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s13293-017-0127-9) contains supplementary material, which is available to authorized users.

Evaluation of self-reported medication adherence and its associated factors among epilepsy patients in Hospital Kuala Lumpur

INTRODUCTION

Reports on medication adherence and its associated factors in patients with epilepsy in South East Asian countries are lacking. The primary purpose of this study was to assess the degree of medication adherence and its relationship with patient's satisfaction, psychosocial factors, quality of life and mental health in a sample of Malaysian epilepsy patients.

METHODOLOGY

It is a cross-sectional study and was carried out in the outpatient Neurology Department of Hospital Kuala Lumpur, Malaysia (n=272). Data was collected by administering the structured questionnaire.

RESULTS AND DISCUSSION

Results showed that 49.3% of the epilepsy patients were non-adherent to their prescribed regimen. Univariate analysis showed significant associations between medication adherence and the following factors: race, seizure frequency, overall patient satisfaction, medication taste and smell, medication cost and physical appearance, medication effectiveness, complexity of medication regimen, patient barrier, patient understanding, patient role functioning, patient positivity, vitality and general interest. Multiple regression analysis indicated that factors that are influencing medication adherence are seizure frequency (P = 0.048), overall patient satisfaction (P = 0.043) and patient understanding about their illness (P = 0.001). The model chosen for testing the relationship between medication adherence and its associated factors give an R2 value of 25.2% with an adjusted R2 of 21.4%. The F value was also significant (P = 0.000). Based on the research findings, the researchers recommends that clinicians need to play a vital role in educating the patients on their disease conditions. By educating the patients on nature of epilepsy, different modalities of treatment and benefits of adherence to treatment will help in the better adherence and management.

Systematic Adverse Drug Reaction Monitoring of Patients Under Newer Antiepileptic Drugs Using Routine Clinical Data of Inpatients

BACKGROUND

Based on data of clinical trials, new agents are receiving approval to the pharmaceutical market, for which information concerning safety issues under real-life conditions is not yet available.

OBJECTIVES

The aim was to evaluate the tolerability of newer antiepileptic drugs (AEDs), such as topiramate, levetiracetam, zonisamide, pregabalin, extended-release oxcarbazepine, lacosamide and eslicarbazepine, under real-life conditions by means of an assessment of routine clinical data of inpatients.

METHOD

Over 2.75 years data of all inpatients receiving one of the newer AEDs were documented. Occurring adverse drug reactions (ADRs) were classified according to the WHO-UMC Causality Assessment concerning their likely relationship to the prescribed AEDs. For each AED, the total number of patients without and with ADRs, assessed as at least possibly related to the particular drug, was calculated and corresponding incidences compared with reference data provided in the Summary of Product Characteristics (SmPC). For statistical evaluation Spearman correlation (rs), estimated relative risk and logistic regression analysis were used.

RESULTS

In total, the data of 562 patients were assessed, of which 90 % received up to six different AEDs. The proportion of off-label use with regard to dosage varied between 6.4 and 64.7 %. Levetiracetam and oxcarbazepine as an extended-release formulation were most commonly used, and levetiracetam showed the best tolerance. By using logistic regression, the occurrence of ADRs was significantly associated with the number of AEDs (p < 0.001) as well as the defined daily doses (p = 0.003). In total, ADRs of AEDs were documented for 318 patients (56.6 %). The most common referred to electrolyte imbalance, e.g., low sodium (n = 79, 14.1 %) and potassium (n = 25, 4.4 %) levels, the central nervous system, including dizziness (n = 61, 10.9 %), disturbed vision (n = 47, 8.4 %), fatigue (n = 40, 7.1 %), nystagmus (n = 36, 6.4 %) and ataxia (n = 29, 5.2 %), or cognitive deficits, especially disturbance of speech (n = 37, 6.6 %), memory impairment (n = 36, 6.4 %) and mental slowing (n = 32, 5.7 %). By comparing the assessed ADR incidences with specification data, for some ADRs, a probable underestimation by the SmPC of respective risk could be assumed.

CONCLUSION

During inpatient treatment, valuable data are generated, which are currently rarely utilized for pharmacoepidemiologic or pharmacovigilance purposes. A systematic evaluation of these data can increase the probability of detecting ADRs and can promote real-life-related drug surveillance.

Emerging drugs for partial-onset epilepsy: a review of brivaracetam

There are more than 12 new antiepileptic drugs approved in the last 2 decades. Even with these newer agents, seizure remission is still unachievable in around 30% of patients with partial-onset seizures (POS). Brivaracetam (BRV) is chemically related to levetiracetam (LEV) and possesses a strong binding affinity for the synaptic vesicle protein 2A tenfold above that of LEV, and other possible modes of antiepileptic actions. BRV is now under Phase III development for POS, but data from one Phase III trial also suggested its potential efficacy for primary generalized seizures. The purpose of this review is to provide updated information on the mechanisms of action of the available antiepileptic drugs, with a focus on BRV to assess its pharmacology, pharmacokinetics, clinical efficacy, safety, and tolerability in patients with uncontrolled POS. To date, six Phase IIb and III clinical trials have been performed to investigate the efficacy, safety, and tolerability of BRV as an adjunctive treatment for patients with POS. Generally, BRV was well tolerated and did not show significant difference in safety profile, compared to placebo. The efficacy outcomes of BRV, although not consistent across trials, did indicate that BRV was a promising add-on therapy for patients with POS. In conclusion, the many favorable attributes of BRV, like its high oral efficacy, good tolerability, dosing regimen, and minimal drug interaction, make it a promising antiepileptic therapy for patients with uncontrolled partial-onset epilepsy.

Analysis of drug use in institutionalized individuals with intellectual disability and tube feeding

OBJECTIVES

Little is known about the medication used by people with intellectual disabilities (ID) and enteral feeding tube (EFT). However, in light of the complexity associated with drug administration through EFT, data on medication use in this population may be helpful in the development of practical guidelines and staff training initiatives.

METHODS

A cross-sectional, observational study was conducted in six Belgian residential care facilities (RCFs) for individuals with ID. Anonymized medication records of all residents receiving chronic medication through EFT were collected (n = 156). All chronic drugs were categorized according to the ATC classification, and medication records were checked for potential major drug-drug interactions (DDI).

RESULTS

The 156 residents used a total of 1029 chronic drugs via EFT, with a median of six drugs per resident (range 1-14). A total of 148 different drug molecules were identified, belonging to 38 main ATC therapeutic groups (ATC level 2). Antiepileptics, drugs for constipation and drugs for acid-related disorders were the most frequently used groups. Seventy-four of the 156 screened medication records (47%) contained at least one potential DDI; in total, 116 potential interactions were identified, which represent 38 different interacting drug pairs.

CONCLUSION

This study describes medication use through EFT among people with ID in Belgian RCFs, with antiepileptics being the most frequently used group. Our study also demonstrated that a high number of drugs is administered through EFT, and that the number of potential DDIs is high. These observations warrant an increased attention for drug administration through the EFT in individuals with ID.

Paroxysmal phenomena in severe disabled children with refractory seizures. From clinical to long-video-EEG processing data to re-examine suspect events

To provide an estimate of the occurrence of misdiagnosis in paroxysmal events in institutionalized children with severe disabilities and refractory epilepsy. A multi-step diagnostic survey, from observational to long-term video-EEG monitoring was performed in 46 severe disabled children. Multirater Kappa statistic was used to assess agreement between investigators and to individualize children who remained with dubious events. Subsequently, prolonged EEG-video monitoring analysis was performed in selected children to define phenomena due to seizures. A total of 128 video records were performed, 64 routine video-EEG and 27 long-monitoring video-EEG data were screened for detailed analysis. Thirty (21 female, 9 male) children (65%) with dubious seizures were identified by video records (concordance K=0.63). Of these, in 18 children (39%) seizures were excluded by routine video-EEG monitoring (K=0.86). Twelve children (26%) required accurate investigations with long-term video-EEG. In 5 children (11%), 3 symptomatic and 2 cryptogenic, very short and subtle seizures were confirmed by investigators concordance (K=0.83). Distinguishing paroxysmal phenomena is a challenge in children with severe disabilities; its most remarkable consequence is inappropriate pharmacological treatment and social costs. Our data suggest that the frequency of misdiagnosis could have been underestimated. The clinicians who manage children with severe disabilities and refractory epilepsy must remain alert to risk of an incorrect treatment.

Cannabidivarin-rich cannabis extracts are anticonvulsant in mouse and rat via a CB1 receptor-independent mechanism

BACKGROUND AND PURPOSE

Epilepsy is the most prevalent neurological disease and is characterized by recurrent seizures. Here, we investigate (i) the anticonvulsant profiles of cannabis-derived botanical drug substances (BDSs) rich in cannabidivarin (CBDV) and containing cannabidiol (CBD) in acute in vivo seizure models and (ii) the binding of CBDV BDSs and their components at cannabinoid CB1 receptors.

EXPERIMENTAL APPROACH

The anticonvulsant profiles of two CBDV BDSs (50-422 mg·kg(-1) ) were evaluated in three animal models of acute seizure. Purified CBDV and CBD were also evaluated in an isobolographic study to evaluate potential pharmacological interactions. CBDV BDS effects on motor function were also investigated using static beam and grip strength assays. Binding of CBDV BDSs to cannabinoid CB1 receptors was evaluated using displacement binding assays.

KEY RESULTS

CBDV BDSs exerted significant anticonvulsant effects in the pentylenetetrazole (≥100 mg·kg(-1) ) and audiogenic seizure models (≥87 mg·kg(-1) ), and suppressed pilocarpine-induced convulsions (≥100 mg·kg(-1) ). The isobolographic study revealed that the anticonvulsant effects of purified CBDV and CBD were linearly additive when co-administered. Some motor effects of CBDV BDSs were observed on static beam performance; no effects on grip strength were found. The Δ(9) -tetrahydrocannabinol and Δ(9) -tetrahydrocannabivarin content of CBDV BDS accounted for its greater affinity for CB1 cannabinoid receptors than purified CBDV.

CONCLUSIONS AND IMPLICATIONS

CBDV BDSs exerted significant anticonvulsant effects in three models of seizure that were not mediated by the CB1 cannabinoid receptor and were of comparable efficacy with purified CBDV. These findings strongly support the further clinical development of CBDV BDSs for the treatment of epilepsy.

Have antiepileptic drug prescription claims changed following the FDA suicidality warning? An evaluation in a state Medicaid program

OBJECTIVE

In January 2008, the Food and Drug Administration (FDA) communicated concerns and, in May 2009, issued a warning about an increased risk of suicidality for all antiepileptic drugs (AEDs). This research evaluated the association between the FDA suicidality communications and the AED prescription claims among members with epilepsy and/or psychiatric disorder.

METHODS

A longitudinal interrupted time-series design was utilized to evaluate Oklahoma Medicaid claims data from January 2006 through December 2009. The study included 9289 continuously eligible members with prevalent diagnoses of epilepsy and/or psychiatric disorder and at least one AED prescription claim. Trends, expressed as monthly changes in the log odds of AED prescription claims, were compared across three time periods: before (January 2006 to January 2008), during (February 2008 to May 2009), and after (June 2009 to December 2009) the FDA warning.

RESULTS

Before the FDA warning period, a significant upward trend of AED prescription claims of 0.01% per month (99% CI: 0.008% to 0.013%, p<0.0001) was estimated. In comparison to the prewarning period, no significant change in trend was detected during (-20.0%, 99% CI: -70.0% to 30.0%, p=0.34) or after (80.0%, 99% CI: -20.0% to 200.0%, p=0.03) the FDA warning period. After stratification, no diagnostic group (i.e., epilepsy alone, epilepsy and comorbid psychiatric disorder, and psychiatric disorder alone) experienced a significant change in trend during the entire study period (p>0.01).

CONCLUSIONS

During the time period considered, the FDA AED-related suicidality warning does not appear to have significantly affected prescription claims of AED medications for the study population.

Inhibition of excitatory synaptic transmission in hippocampal neurons by levetiracetam involves Zn²⁺-dependent GABA type A receptor-mediated presynaptic modulation

Levetiracetam (LEV) is an antiepileptic drug with a unique but as yet not fully resolved mechanism of action. Therefore, by use of a simplified rat-isolated nerve-bouton preparation, we have investigated how LEV modulates glutamatergic transmission from mossy fiber terminals to hippocampal CA3 neurons. Action potential-evoked excitatory postsynaptic currents (eEPSCs) were recorded using a conventional whole-cell patch-clamp recording configuration in voltage-clamp mode. The antiepileptic drug phenytoin decreased glutamatergic eEPSCs in a concentration-dependent fashion by inhibiting voltage-dependent Na⁺ and Ca²⁺ channel currents. In contrast, LEV had no effect on eEPSCs or voltage-dependent Na⁺ or Ca²⁺ channel currents. Activation of presynaptic GABA type A (GABA(A)) receptors by muscimol induced presynaptic inhibition of eEPSCs, resulting from depolarization block. Low concentrations of Zn²⁺, which had no effect on eEPSCs, voltage-dependent Na⁺ or Ca²⁺ channel currents, or glutamate receptor-mediated whole cell currents, reduced the muscimol-induced presynaptic inhibition. LEV applied in the continuous presence of 1 µM muscimol and 1 µM Zn²⁺ reversed this Zn²⁺ modulation on eEPSCs. The antagonizing effect of LEV on Zn²⁺-induced presynaptic GABA(A) receptor inhibition was also observed with the Zn²⁺ chelators Ca-EDTA and RhodZin-3. Our results clearly show that LEV removes the Zn²⁺-induced suppression of GABA(A)-mediated presynaptic inhibition, resulting in a presynaptic decrease in glutamate-mediated excitatory transmission. Our results provide a novel mechanism by which LEV may inhibit neuronal activity.

The long-term safety of antiepileptic drugs

Antiepileptic drugs (AEDs) are used by millions of people worldwide for the treatment of epilepsy, as well as in many other neurological and psychiatric conditions. They are frequently associated with adverse effects (AEs), which have an impact on the tolerability and success of treatment. Half the people who develop intolerable AEs discontinue treatment early on after initiation, while the majority of people will continue to be exposed to their effects for long periods of time. The long-term safety of AEDs reflects their potential for chronic, cumulative dose effects; rare, but potentially serious late idiosyncratic effects; late, dose-related effects; and delayed, teratogenic or neurodevelopmental effects. These AEs can affect every body system and are usually insidious. With the exception of delayed effects, most other late or chronic AEs are reversible. To date, there is no clear evidence of a carcinogenic effect of AEDs in humans. While physicians are aware of the long-term AEs of old AEDs (the traditional liver enzyme-inducing AEDs and valproate), information about AEs of new AEDs (such as lamotrigine, levetiracetam, oxcarbazepine, topiramate or zonisamide), particularly of their teratogenic effects, has emerged over the years. Sporadic publications have raised issues about AEs of the newer AEDs eslicarbazepine, retigabine, rufinamide, lacosamide and perampanel but their long-term safety profiles may take years to be fully appreciated. Physicians should not only be aware of the late and chronic AEs of AEDs but should systematically enquire and screen for these according to the individual AED AE profile. Care should be taken for individuals with comorbid conditions that may render them more susceptible to specific AEs. Prevention and appropriate management of long-term AED AEs is expected to improve adherence to treatment, quality of life and control of epilepsy.

Self-reported symptoms in patients on antiepileptic drugs in monotherapy

OBJECTIVE

To ascertain the frequency of self-reported symptoms in patients taking antiepileptic drugs (AED).

METHODS

We included patients on carbamazepine (CBZ) n = 36, valproate (VPA) n = 21, levetiracetam (LEV) n = 12, phenytoin (PHT) n = 11, lamotrigine (LTG) n = 20, patients not taking anticonvulsive drugs n = 19, and healthy control subjects (CTRL) n = 41 to complete the Liverpool Adverse Event Profile (LAEP).

RESULTS

The mean LAEP scores were CBZ/PHT/LEV/VPA/LTG/noAED/CTRL = 44.97/42.00/41.00/40.33/32.42/42.00/30.80. LEV scored overall in the same range as the older AED but had a different adverse effect profile with self-reported anger (33%) and shaky hands (42%) particularly frequent. Patients with depression or uncontrolled epilepsy had significantly higher LAEP scores than patients without depression or uncontrolled epilepsy.

CONCLUSION

Our unblinded observational study of self-reported symptoms suggested LTG was overall the drug with the least self-reported symptoms. Larger studies are needed to determine whether this was a truly significant difference. LEV had a different side effect profile to older AED. Confounding factors were depression and uncontrolled epilepsy. This observation should be further tested with randomized studies.

Age and sex dependent changes in liver gene expression during the life cycle of the rat

Background

Age- and sex-related susceptibility to adverse drug reactions and disease is a key concern in understanding drug safety and disease progression. We hypothesize that the underlying suite of hepatic genes expressed at various life cycle stages will impact susceptibility to adverse drug reactions. Understanding the basal liver gene expression patterns is a necessary first step in addressing this hypothesis and will inform our assessments of adverse drug reactions as the liver plays a central role in drug metabolism and biotransformation. Untreated male and female F344 rats were sacrificed at 2, 5, 6, 8, 15, 21, 52, 78, and 104 weeks of age. Liver tissues were collected for histology and gene expression analysis. Whole-genome rat microarrays were used to query global expression profiles.

Results

An initial list of differentially expressed genes was selected using criteria based upon p-value (p < 0.05) and fold-change (+/- 1.5). Three dimensional principal component analyses revealed differences between males and females beginning at 2 weeks with more divergent profiles beginning at 5 weeks. The greatest sex-differences were observed between 8 and 52 weeks before converging again at 104 weeks. K-means clustering identified groups of genes that displayed age-related patterns of expression. Various adult aging-related clusters represented gene pathways related to xenobiotic metabolism, DNA damage repair, and oxidative stress.

Conclusions

These results suggest an underlying role for genes in specific clusters in potentiating age- and sex-related differences in susceptibility to adverse health effects. Furthermore, such a comprehensive picture of life cycle changes in gene expression deepens our understanding and informs the utility of liver gene expression biomarkers.

Antiepileptic drugs and quality of life in the elderly: results from a randomized double-blind trial of carbamazepine and lamotrigine in patients with onset of epilepsy in old age

During an international double-blind trial evaluating the efficacy and tolerability of lamotrigine and carbamazepine in patients aged >or=65 with newly diagnosed epilepsy, the comparative effects of the drugs on health-related quality of life were investigated based on screening and 12-, 28-, and 40-week data, using the modified Side Effect and Life Satisfaction (SEALS) Inventory and the Liverpool Adverse Event Profile. Of 167 patients, 29 discontinued before first follow-up, and data were incomplete for 13. In 125 eligible subjects (62 taking carbamazepine, 63 taking lamotrigine), comparable baseline data did not change significantly during medication, within or across treatments. A borderline difference in the SEALS Dysphoria subscores favored lamotrigine. No difference between completers and noncompleters was identified. Twelve-week data for noncompleters were comparable across treatments. Changes in the inventories up to 40 weeks correlated moderately. Neither lamotrigine nor carbamazepine seems likely to cause significant changes in health-related quality of life measures after 40 weeks at therapeutic doses.

The impact of 'social determinants of health' on epilepsy prevalence and reported medication use

There is a limited understanding of the complex relationship between poverty and epilepsy. To address the complex interaction of environmental and psychosocial factors in epilepsy a 'social determinants of health' model is presented where individual factors are influenced through three pathways (social environment, work and material factors). In the 2005 California Health Interview Survey, 246 of 604 (41%) persons with a history of epilepsy were in poverty, defined as <200% Federal Poverty Level (FPL). Multivariable logistic regression analyses revealed persons in poverty are not more likely to report a history of epilepsy compared to those not in poverty. However, persons with a history of epilepsy in poverty were significantly less likely than those not in poverty to report taking medication for epilepsy (OR 0.5) once material factors (annual income and living situation) and healthcare access were controlled for in the final sequential model. Healthcare practitioners must continue to recognize that connection to social services and the cost of medications are significant barriers to optimal care in persons with epilepsy. Improved connection to patient advocacy organizations and medication assistance programs may help close these gaps.

Designing clinical trials to assess antiepileptic drugs as monotherapy : difficulties and solutions

Designing monotherapy trials in epilepsy is fraught with many hurdles, including diagnostic and classification difficulties, sparse information regarding the natural history of the disorder, and ethical objections to the use of placebo or a suboptimal comparator in a condition where the consequences of therapeutic failure can be serious. These issues are further complicated by regulatory differences between the US and the EU.In the US, the FDA considers that evidence of efficacy requires demonstration of superiority to a comparator. Because available antiepileptic drugs possess relatively high efficacy, in most settings it is unrealistic to expect that a new treatment will be superior to a standard treatment used at optimized dosages. To circumvent this problem, trial designs have been developed whereby patients in the control group are assigned to receive a suboptimal comparator and are required to exit from the trial if seizure deterioration occurs. This allows demonstration of a between-group difference in efficacy endpoints, such as time to exit or time to first seizure. Although these trials have come under increasing criticism because of ethical concerns, extensive information is now available on the outcome of patients with chronic epilepsy randomized to suboptimal treatment in similarly designed conversion to monotherapy trials. This has allowed the construction of a dataset of historical controls against which response to a fully active treatment can be compared. A number of studies using this novel approach are now in progress.In the EU, in addition to requiring data on conversion to monotherapy in refractory patients, the European Medicines Agency stipulates that a monotherapy indication in newly diagnosed epilepsy can only be granted if a candidate drug has shown at least a similar benefit/risk balance compared with an acknowledged standard at its optimal use during an assessment period of no less than 1 year. This has led to the implementation of noninferiority trials, one of which has been completed and which led to approval of the monotherapy indication for levetiracetam in the EU. Noninferiority trials provide valuable data in a setting that most closely resembles routine clinical practice, but their interpretation can be complicated by uncertainties on assay sensitivity.Major evidence gaps in the treatment of epilepsy still remain and it is hoped that these will be addressed in the near future. High quality monotherapy trials are particularly needed to assess the comparative efficacy of older and newer drugs in less common epilepsy syndromes, including most generalized epilepsies, and to investigate the different treatment options in populations homogeneous not only in terms of syndromic classification, but also in terms of underlying aetiology and associated phenotypes.

Supportive management of patients with brain tumors

Management issues for patients with brain tumors include peritumoral edema, symptomatic seizures, venous thromboembolism, headache, pain, fatigue and neuropsychological complaints. Vasogenic edema is typically ameliorated with the lowest dose possible of corticosteroid. Seizures are managed with attention to additional or complicated side effects of antiepileptic drugs and their interactions with chemotherapy, and primary prevention with antiepileptic medications is not recommended. Appropriate treatments for headache, pain, fatigue and neuropsychological complaints are important, but are not yet well standardized. Above all, patients' personal goals regarding their priorities at the end of life have the most importance.

Use and safety profile of antiepileptic drugs in Italy

OBJECTIVE

To analyse and discuss the use and the safety profile of individual antiepileptic drugs (AEDs) in Italy.

METHODS

The AED safety data referred to the period January 1988-June 2005 and were obtained from the database of the Italian Interregional Group of Pharmacovigilance (GIF). This database collects all spontaneous reports of suspected adverse drug reactions (ADRs) from six Italian regions which are the main contributors to the Italian spontaneous reporting system. Individual AED consumption data (defined daily dose/1,000 inhabitants per day) in the GIF area and in the whole of Italy referred to the period January 2003-June 2005 and were derived from drug sales data (Institute for Medical Statistics Health).

RESULTS

Phenobarbital was the most frequently used AED in the GIF area (4.26 DDD/1,000 inhabitants per day) followed by carbamazepine (1.97), valproic acid (1.33) and gabapentin (1.10). AED consumption in the whole of Italy showed a similar pattern. Gabapentin was the most frequently used AED among newer AEDs. In the GIF database 37,906 reports (up to June 2005) were present; 666 of them (1.76%) were associated with at least one AED (Anatomical Therapeutic Chemical code N03A). The AED with the highest number of reports was carbamazepine (208 reports) followed by phenobarbital (98), gabapentin (80), phenytoin (56), valproic acid (55), lamotrigine (51), oxcarbazepine (43) and vigabatrin (35). Use and toxicity profile were evaluated only for AEDs associated with at least 30 reports. Skin reactions were the most frequently reported ADRs, followed by haematological, general condition, hepatic, neurological and gastrointestinal adverse reactions. Phenobarbital, lamotrigine, carbamazepine and phenytoin had the highest percentage of skin reactions (69, 67, 60 and 54%, respectively). Many haematological reactions were reported for each AED; the highest percentage was related to valproic acid (25%). Vigabatrin was associated with the highest percentage of reactions related to hearing, vision and other senses (97%). Phenytoin and valproic acid had the highest percentage of hepatic reactions (30 and 20%), whereas gabapentin of nervous system, psychiatric, gastrointestinal and urinary reactions (26, 21, 21 and 14%, respectively) and phenobarbital of musculoskeletal reactions (13%).

CONCLUSIONS

In Italy antiepileptic drug therapy appears to be still dominated by traditional drugs. Our analysis showed a different safety profile related to each AED. Some of the drug-adverse reaction associations discussed are not included in the Italian drug leaflets or have not been reported before in the literature.

Seletracetam (UCB 44212)

Better pharmacotherapies for epilepsy are needed for patients who are refractory to or have tolerability difficulties with current treatments. Seletracetam, a new drug in epilepsy development, is a pyrrolidone derivative structurally related to levetiracetam (trade name Keppra). It was discovered because of its high binding affinity to the synaptic vesicle 2A (SV2A) protein, which is now known to be the binding site for this family of compounds. Seletracetam shows very potent seizure suppression in models of acquired or genetic epilepsy, as well as high CNS tolerability in various animal models. Pharmacokinetic studies in animals suggest that seletracetam is rapidly and highly absorbed, with linear and time-independent pharmacokinetics. Seletracetam appears neither to inhibit nor to induce the major human drug metabolizing enzymes, and it demonstrates low plasma protein binding (<10%), which suggests a low potential for drug-drug interactions. Initial studies in humans demonstrated first-order monocompartmental kinetics with a half-life of 8 h and an oral bioavailability of >90%. Studies in healthy volunteers showed that the treatment emergent adverse events were of mild to moderate severity, were mostly of CNS origin and were resolved within 24 h. Altogether, these results suggest that seletracetam represents a promising new antiepileptic drug candidate, one that demonstrates a potent, broad spectrum of seizure protection and a high CNS tolerability in animal models, with initial clinical findings suggestive of straightforward pharmacokinetics and good tolerability.

Overtreatment in epilepsy: how it occurs and how it can be avoided

In pharmacotherapy, overtreatment may be defined as an excessive drug load (that is, excessive drug dosages or unnecessary polypharmacy) leading to a suboptimal risk-to-benefit ratio. The risk of overtreatment in the pharmacological management of epilepsy is substantial and may have serious consequences in terms of a greater incidence and severity of adverse effects. These effects can range from subtle CNS impairment to overt toxic effects, including teratogenicity. Overtreatment also causes increased treatment costs and may even lead to a paradoxical deterioration in seizure control. The prevention and correction of overtreatment requires a thorough understanding of the situations and mechanisms that lead to inappropriate prescribing of antiepileptic drugs. These include initiating treatment in conditions where it is not indicated (for example, long-term prophylaxis after head trauma or supratentorial surgery in seizure-free patients), use of excessively fast titration rates, prescription of excessively high initial target dosages, failure to consider conditions associated with reduced dosage requirements (for example, old age or comorbidities associated with impaired drug clearance), and failure to consider the dose-response characteristics of the selected drug. Many patients whose seizures do not respond to the initially prescribed medication can be optimally managed by switching to monotherapy with an alternative agent; premature use of combination therapy represents another common form of overtreatment. Overtreatment may also result from a failure to adjust the dosage to prevent or compensate for adverse pharmacokinetic or pharmacodynamic drug interactions, and from a failure to reduce drug load in patients who have not benefited from high dosages or polypharmacy. While the measurement of drug concentrations can aid in minimising adverse effects, there is also a danger of overtreatment resulting from inappropriate interpretation of drug concentration data. Continuation of drug therapy in seizure-free patients in whom the risk-benefit ratio is in favour of gradual withdrawal may also be regarded as overtreatment. Tailoring therapy to the needs of the individual patient is the key to the successful management of epilepsy. Even though the importance of complete seizure control cannot be overemphasised, no patient should be made to suffer more from the adverse effects of treatment than from the manifestations of the seizure disorder.

Active control trials: Endpoints beyond conventional efficacy and tolerability measures

Clinical trial endpoints often extend beyond conventional efficacy and tolerability measures. While it is generally assumed that seizure control without major adverse drug effects is by far the most important determinant of quality of life, other factors also are important. Pharmacokinetic endpoints could also provide relevant information for optimal drug use. Outcome measures could reveal drug effects on mood, headache, and sleep disorders, as well as overall quality of life and seizure severity.

Adverse effects of antiepileptic drugs

Adverse effects of antiepileptic drugs (AEDs) are common, can have a considerable impact on quality of life and contribute to treatment failure in up to 40% of patients. The adverse effect profiles of AEDs differ greatly and are often a determining factor in drug selection because of the similar efficacy rates shown by most AEDs. The most common adverse effects are dose dependent and reversible. Cognitive impairment is of particular concern, especially for patients who work or study. Idiosyncratic effects, such as skin rashes, and chronic effects, such as weight gain, can lead to high rates of treatment discontinuation and complicate clinical management. Nearly all conventional AEDs increase the risk of congenital malformations when taken during pregnancy, with valproate posing a potentially greater risk, whereas the potential teratogenicity of new generation AEDs is largely unknown. Most conventional AEDs have a poor record when it comes to drug interactions, largely because of their tendency to interfere with hepatic drug metabolism. Some newer AEDs have no effect on hepatic drug metabolizing enzymes and are renally excreted, resulting in a lower potential for drug interactions. However, further research is needed to confirm the apparent improvement in tolerability offered by some of the newer AEDs.

Carbamazepine extended-release capsules vs. oxcarbazepine: computer simulations of the effect of missed doses on drug plasma concentrations

OBJECTIVE

Plasma concentrations of antiepileptic drugs (AEDs) can vary and are not always an indication of clinical utility. However, adverse event occurrence can be correlated to fluctuations in plasma drug levels that occur with varying dosing regimens of the many AEDs. In this study, we present the results of computer simulations of plasma concentrations of the AEDs carbamazepine (CBZ) extended-release capsules (CBZ-ERC) (Carbatrol) and oxcarbazepine (OXC).

RESEARCH DESIGN AND METHODS

A one-compartment open model with first-order absorption and elimination was generated from the results of a previous study measuring plasma concentrations following one 400 mg fasting dose of CBZ-ERC. This model was used to simulate plasma concentrations of CBZ following multiple 400 mg doses of CBZ-ERC at 12-hour intervals, and then when a missed dose is taken 3, 6, or 9 hours late; when two doses are taken at one time; and when a single dose is taken at the time of the next dosing. In comparison, similar modeling was done for monohydroxy derivative (MHD) of OXC at doses of 600 or 1200 mg.

RESULTS

Plasma drug concentrations after 24 hours without medication were 4.1 mg/L for CBZ-ERC, 8 mg/L for 600 mg OXC, and 16 mg/L for 1200 mg OXC. If a patient was to take only a single dose 24 hours late, it would take 24 hours to reach steady-state trough values for CBZ-ERC, 36 hours for 600 mg OXC, and 2 days for 1200 mg OXC. The trough plasma concentration following a missed dose and the peak plasma concentration following a double dose (administered 12 hours after the missing of a dose) differed by a factor of two in the CBZ-ERC simulation, compared with a factor of three in both OXC simulations.

CONCLUSIONS

The ultimate goal of antiepileptic therapy is a seizure-free state without side effects. The current computer simulation study indicates that AEDs such as CBZ-ERC and OXC, which produce relatively stable plasma concentrations, should be useful in attaining this goal. Nonetheless, simulated plasma concentrations resulting from CBZ-ERC treatment tended to oscillate less dramatically compared with simulated plasma concentrations resulting from treatment with 600 or 1200 mg OXC.

An Introduction to Antiepileptic Drugs

In recent years, the number of commercially available antiepileptic drugs (AEDs) has increased steadily. Although this may complicate management choices, it also offers welcome new options to individualize treatment more effectively. Because each of the available AEDs differs from others in many clinically relevant properties, opportunities to tailor drug treatment to the characteristics of the individual patient have never been greater. Properties that are especially important in drug selection in patients with epilepsy include spectrum of efficacy in different seizure types, adverse effects profile, pharmacokinetic properties, susceptibility to cause or be a target of clinically important drug-drug interactions, ease of use, and cost. Other factors that need to be considered in tailoring drug choice include availability of user-friendly pediatric formulations, and potentially favorable effects on co-morbid conditions. In fact, a number of AEDs are efficacious and widely prescribed in additional indications, particularly psychiatric disorders, migraine prophylaxis, and neuropathic pain. Recently, advances have been made in understanding the mechanisms of actions of AEDs at the molecular level. While a fully mechanistic approach to the clinical use of these agents is not yet feasible, knowledge of mechanisms of action offers useful clues in predicting their efficacy profile and spectrum of potential adverse effects.

Efficacy and safety of levetiracetam: An add-on trial in children with refractory epilepsy

The aim of this multicentric, prospective and uncontrolled study was to evaluate the efficacy and safety of levetiracetam in 110 children with refractory epilepsy, of whom 21 were less than 4 years old. After a median follow-up period of 7 months, levetiracetam administration was effective (responders with >50% decrease in seizure frequency) in 39% of children, of whom 10 (9%) became seizure-free. The efficacy was higher in patients with localization-related epilepsy (58% of responders) than in those with generalized epilepsy (37% of responders). Levetiracetam was well tolerated. The main side effects of somnolence and irritability occurred in 14% of patients. In one patient acute choreoathetosis occurred after few doses of levetiracetam. Overall, the adverse effects were not severe. Children younger than 4 years were particularly tolerant. In conclusion, the present study confirms that levetiracetam is effective and well tolerated as an add-on treatment in children with refractory epilepsy. Our preliminary data also indicate that levetiracetam may be a valid therapeutic option for epilepsy in infants and young children.

Efficacy and safety of topiramate in infants according to epilepsy syndromes

Studies of the efficacy of topiramate (TPM) in infants and young children are few. Here we report an open, prospective, and pragmatic study of effectiveness of TPM in terms of epilepsy syndromes, in children aged less than 2 years. The median follow-up period was 11 months. We enrolled 59 children in the study: 22 affected by localization-related epilepsy (LRE), 23 by generalized epilepsy, six by Dravet's syndrome, and eight with unclassifiable epilepsy. TPM was effective (responders showed a decrease of more than 50% in seizure frequency) in 47% of patients, including 13% who were seizure-free at the last visit. TPM was more effective in localization-related epilepsy (48% of responders) than in generalized epilepsy (32% of responders). In the latter group, 19 patients suffered from infantile spasms. Four of six patients with cryptogenic infantile spasms became seizure-free. Of the 13 patients with symptomatic infantile spasms, only one was seizure-free. Results were poor for patients with Dravet's syndrome. In general, TPM was well tolerated. The most frequently reported adverse effects were drowsiness, irritability, hyperthermia, and anorexia. The present study concludes that TPM is effective for a broad range of seizures in infants and young children and represents a valid therapeutic option in this population.